Sample delivery system for analytical instrument

Abstract

The invention provides a sample delivery system for an analytical instrument, comprising: a valve assembly comprising one or more valves, the valve assembly configured to receive an external sample from a sample source; and an external sample reservoir, the external sample reservoir being coupled to a sample dilution junction via the valve assembly, the valve assembly may be configured to alternatively allow (i) flow of the external sample from the sample source to the external sample reservoir, or (ii) flow of the external sample from the external sample reservoir to the sample dilution junction; a first fluid pump for controlling flow of the external sample from the external sample reservoir to the sample dilution junction; a second fluid pump for controlling flow of a diluent to the sample dilution junction, thereby diluting the external sample to produce a diluted sample; and an analytical sample reservoir configured to deliver an analytical sample contained therein to an analytical device of the analytical instrument, where the analytical sample reservoir is coupled to the sample dilution junction via the valve assembly, and where the analytical sample reservoir is configured to deliver the analytical sample contained therein to the analytical device of the analytical instrument. The valve assembly may be configured to alternatively allow (i) the external sample to flow along a continuous flow path from the sample source to the analytical sample reservoir, thereby bypassing the external sample reservoir, or (ii) the diluted sample to flow from the sample dilution junction to the analytical sample reservoir.

Description

[0001] This application claims priority to Australian Provisional Patent Application No. 2022901996 filed on July 15, 2022, the contents of which should be understood to be incorporated into this specification by this reference. Technical Field

[0002] The present invention relates to a sample delivery system for an analytical instrument, such as an inductively coupled plasma (ICP) spectrometer. The present invention further relates to a spectrometer comprising the sample delivery system, and to a method of performing analysis using a spectrometer. Background Art

[0003] Inductively coupled plasma (ICP) spectroscopy is an analytical technique for detecting and quantifying the isotopic distribution of chemical elements and / or chemical elements present in liquid samples. An ICP spectrometer includes a plasma torch powered by a radio frequency (RF) generator, which ionizes argon gas to produce argon plasma at a temperature of about 7000K. The liquid sample to be analyzed is typically atomized to form an aerosol suitable for contact with the plasma. The plasma evaporates the sample solvent and decomposes the analyte molecules into their constituent atoms, which are ionized and / or excited to higher energy states. The elemental composition of the sample is then determined by measuring the optical emission spectrum of the sample (in an ICP-OES spectrometer) or the mass spectrum of the ionized sample (in an ICP-MS spectrometer).

[0004] ICP spectroscopy is used as a routine analytical technique in a wide variety of industries. There is a strong motivation to automate the operation of ICP spectrometers, thereby minimizing human operator involvement and maximizing the average rate at which samples can be analyzed in an ICP spectrometer, thereby increasing instrument productivity.

[0005] ICP spectrometers typically require regular calibration by analyzing standard solutions containing known concentrations of various analyte elements and creating calibration curves. The calibration curve will span a range of concentrations that cover the concentrations typically expected in the sample to be analyzed and / or the concentrations within the range in which the instrument provides a linear response. However, it is common in practice that some samples (e.g., up to 20%) will be over-range for one or more analytes. Therefore, in order to obtain accurate quantification, it is necessary to dilute the sample to ensure that the over-range analyte is within the calibration range, reanalyze the diluted sample, and reversely calculate the analyte concentration in the undiluted sample based on the known dilution level of the diluted sample.

[0006] A variety of different methods have been used previously to dilute samples using ICP-MS and ICP-OES instruments. At its most basic, samples are diluted to a predetermined dilution level prior to analysis, either manually or by automated off-line dilution. However, systems that are unable to dilute to the instrument's required level do not offer the benefit of automatically diluting samples that are found to be out of range, and therefore have only a limited impact on instrument productivity. Other systems can provide automated off-line sample dilution or online sample dilution (in an autosampler) to reach the instrument's required dilution level, but there is a risk of carryover contamination because all samples are diluted in the same dilution vial.

[0007] Various online sample dilution systems have been proposed previously. U.S. Patent 9,239,581 discloses a sample delivery system for an ICP spectrometer in which a diluent can be mixed with the sample stream immediately before being delivered to the nebulizer. However, an ICP spectrometer requires a near-constant, low flow rate of liquid to the nebulizer to maintain plasma stability, and for the sampling arrangement of US 9,239,581, the flow to the nebulizer is interrupted between dilutions.

[0008] Both U.S. Patents 10,241,013 and 11,056,328 disclose an online dilution system with two modules. In the first (sample dilution) module, an external sample is loaded from an autosampler into a first sample loop. The sample then flows from the first sample loop and is diluted online with a diluent stream to produce a diluted sample with a target dilution level. The diluted sample is transferred to the second (sample delivery) module, where it is loaded into the second sample loop. The diluted sample then flows out of the second sample loop and is delivered to the ICP analyzer. Although this arrangement provides accurate online dilution of samples across a wide range of dilution levels, it has the following disadvantages: even if no dilution is required, all samples must pass through two modules of the online dilution system. Transferring the sample through the sample dilution module significantly increases the analysis time, wherein the undesirable impact on the instrument productivity is particularly evident in the use scenario where only a few samples need to be diluted. In addition, the first sample loop must accommodate a significantly larger volume than the second sample loop to allow the undiluted sample to be representatively transferred to the second loop for analysis.

[0009] While the foregoing discussion has focused on ICP spectroscopy, it will be apparent that similar considerations apply to sample delivery systems for a range of other analytical instruments, including but not limited to other spectrometers that include a plasma source for sample processing, such as microwave plasma spectrometers.

[0010]

[0006] Therefore, there is a continuing need for a sample delivery system for an analytical instrument that at least partially addresses one or more of the above-mentioned disadvantages or provides a useful alternative.

[0011] The reference herein to a patent document or other matter cited as prior art should not be taken as an admission that the document or matter was known or that the information it contained was part of the common general knowledge as at the priority date of any claim. Summary of the invention

[0012] The present invention provides a sample delivery system for an analytical instrument, and the sample delivery system can operate in two modes. In the first mode, the sample delivery system is configured to provide a continuous flow path from a sample source (such as an automatic sampler) to an analysis sample reservoir (typically configured as a sample loop). Therefore, an external sample can be directly loaded into the analysis sample reservoir from the sample source, and unloaded to the analyzer via a single (sample delivery) module without online dilution. In the second mode, the sample delivery system is configured to perform online dilution and sample delivery via two modules. In the sample dilution module, the external sample is initially loaded into the external sample reservoir (optionally also configured as a sample loop), then subsequently flows from the external sample reservoir and is diluted online by a controlled flow of a diluent. The diluted sample is transferred to a sample delivery module, where it flows to the analysis sample reservoir, and then unloaded to the analyzer similar to the first operating mode. Because the sample dilution module is bypassed in the first mode, undiluted samples can be analyzed quickly. The sample dilution module is only used for those samples that require dilution, thereby minimizing the impact on overall instrument productivity. Furthermore, the bypass arrangement allows the size of the external sample reservoir to be reduced, since the external sample contained therein is always diluted when transferred to the analytical sample reservoir.

[0013] According to a first aspect, the present invention provides a sample delivery system for an analytical instrument, comprising: a valve assembly, the valve assembly comprising one or more valves, the valve assembly being configured to receive an external sample from a sample source; an external sample reservoir, the external sample reservoir being connected to a sample dilution junction via the valve assembly, wherein the valve assembly can be configured to alternatively allow (i) the external sample to flow from the sample source to the external sample reservoir, or (ii) the external sample to flow from the external sample reservoir to the sample dilution junction; a first fluid pump, the first fluid pump being used to control the flow of the external sample from the external sample reservoir to the sample dilution junction; a second a fluid pump for controlling the flow of a diluent to the sample dilution junction, thereby diluting the external sample to produce a diluted sample; and an analytical sample reservoir, the analytical sample reservoir being configured to deliver the analytical sample contained therein to an analytical device of the analytical instrument, wherein the analytical sample reservoir is connected to the sample dilution junction via the valve assembly, and wherein the valve assembly can be configured to alternatively allow (i) the external sample to flow along a continuous flow path from the sample source to the analytical sample reservoir, thereby bypassing the external sample reservoir, or (ii) the diluted sample to flow from the sample dilution junction to the analytical sample reservoir.

[0014] In some embodiments, the analysis sample reservoir is configured as an analysis sample loop, which is coupled to two ports of a first multi-port valve of the valve assembly, wherein an analysis sample can be loaded into the analysis sample loop when the first multi-port valve is in a first valve position, and wherein the analysis sample can be delivered from the analysis sample loop to the analysis device when the first multi-port valve is switched to a second valve position. The sample delivery system may further include a third fluid pump for flowing a first carrier fluid to the first multi-port valve, wherein the first multi-port valve may be configured to flow the first carrier fluid directly through the first multi-port valve to the analysis device when the first multi-port valve is in the first valve position, and to divert the first carrier fluid through the analysis sample loop when the first multi-port valve is switched to the second valve position, thereby delivering the analysis sample from the analysis sample loop to the analysis device. Optionally, the sample delivery system may further include a bubble injector configured to inject gas bubbles to separate the first carrier fluid from the analysis sample when the first carrier fluid flows through the analysis sample loop.

[0015] In some embodiments, the sample delivery system further includes a fourth fluid pump or vacuum source preferably located downstream of the analysis sample reservoir, the fourth fluid pump or vacuum source being used to flow the external sample along the continuous flow path from the sample source to the analysis sample reservoir. The sample delivery system can be adapted to bypass the fourth fluid pump or vacuum source when the diluted sample flows from the sample dilution junction to the analysis sample reservoir. The valve assembly can be configurable to allow the fourth fluid pump or vacuum source to flow the external sample from the sample source to the external sample reservoir.

[0016] In some embodiments, the valve assembly can be configured to allow the first fluid pump to flow the external sample from the sample source to the external sample reservoir.

[0017] In some embodiments, the valve assembly includes a second multi-port valve coupled to the analysis sample reservoir, wherein the second multi-port valve can be switched between at least a first valve position and a second valve position, the first valve position allowing the flow of the external sample along the continuous flow path from the sample source to the analysis sample reservoir, and the second valve position allowing the flow of the diluted sample from the sample dilution junction to the analysis sample reservoir. The second multi-port valve can be switchable to a third valve position to allow the flow of the external sample from the sample source to the external sample reservoir. When the second multi-port valve is switched to the second valve position, the second fluid pump can control the flow of diluent through the second multi-port valve to the sample dilution junction. Optionally, the sample dilution junction is inside the second multi-port valve.

[0018] In some embodiments, the external sample reservoir is configured to be coupled to an external sample loop of a valve of the valve assembly.

[0019] In some embodiments, the external sample reservoir is configured as an external sample loop, the external sample loop is coupled to two ports of a third multi-port valve of the valve assembly, wherein the external sample can be loaded into the external sample loop when the third multi-port valve is in a second valve position, and wherein the external sample can be delivered from the external sample loop to the sample dilution junction when the third multi-port valve is switched to a first valve position. The valve assembly can be configured to allow the first fluid pump to flow a second carrier fluid through the external sample loop when the third multi-port valve is switched to the first valve position, thereby causing the external sample to flow from the external sample loop to the sample dilution junction. The sample delivery system can be configured to introduce gas bubbles when the second carrier fluid flows through the external sample loop to space the second carrier fluid from the external sample. The valve assembly can be configured to allow the second fluid pump to flow the diluent through the third multi-port valve to the sample dilution junction when the third multi-port valve is in the first valve position. Optionally, the sample dilution junction is inside the third multi-port valve. The valve assembly may be configurable to allow flow of the external sample along the continuous flow path from the sample source via the third multi-port valve to the analytical sample reservoir when the third multi-port valve is in the first valve position.

[0020] In some embodiments, the first fluid pump and the second fluid pump are configured to flow the external sample and the diluent at a relative flow rate (v / v) in a range from 10:1 to 1:1000 (e.g., in a range from 1:1 to 1:250).

[0021] In some embodiments, the first fluid pump and the second fluid pump are configured to flow the external sample and the diluent at a combined flow rate between 2 ml / min and 20 ml / min (e.g., between 5 ml / min and 15 ml / min, such as approximately 10 ml / min).

[0022] In some embodiments, the volume of the external sample reservoir is no more than 20% greater than the volume of the analytical sample reservoir. In some embodiments, the volume of the external sample reservoir is no greater than the volume of the analytical sample reservoir.

[0023] In some embodiments, the sample delivery system further comprises the sample source, wherein the sample source is coupled to the external sample reservoir and to the analytical sample reservoir via the valve assembly.The sample source may be selected from an autosampler and an automated interface adapted to sample process fluids.

[0024] According to a second aspect, the present invention provides a spectrometer comprising an analysis device and a sample delivery system according to any embodiment of the first aspect.

[0025] In some embodiments, the analytical device includes a plasma source.

[0026] In some embodiments, the spectrometer is an ICP-OES and / or ICP-MS spectrometer.

[0027] In some embodiments, the spectrometer further includes a computing device, which is used to control the sample delivery system to deliver an external sample for spectral analysis by method (a) or method (b), wherein: method (a) includes (i) causing the external sample to flow from the sample source to the analysis sample reservoir along the continuous flow path without diluting the external sample, and (ii) subsequently delivering the external sample from the analysis sample reservoir to the analysis device for spectral analysis, and method (b) includes (i) causing the external sample to flow from the sample source to the external sample reservoir, (ii) subsequently causing the external sample to flow from the external sample reservoir to the sample dilution junction, (iii) simultaneously causing a diluent to flow to the sample dilution junction thereby diluting the external sample to produce a diluted sample, (iv) causing the diluted sample to flow from the sample dilution junction to the analysis sample reservoir, and (v) subsequently delivering the diluted sample from the analysis sample reservoir to the analysis device for spectral analysis.

[0028] In some embodiments, the computing device is adapted to: deliver a first external sample for spectral analysis by method (a); determine a target dilution of the first external sample based on the spectral analysis of the first external sample; and deliver a diluted sample comprising the first external sample and the diluent for spectral analysis by method (b), wherein the first fluid pump and the second fluid pump are controlled to cause the first external sample and the diluent to flow at relative flow rates suitable for achieving the target dilution in the diluted sample.

[0029] According to a third aspect, the present invention provides a method for analysis using a spectrometer according to any embodiment of the second aspect, the method comprising: providing one or more external samples at a sample source for analysis; and analyzing at least a first sample of the one or more external samples by a first analysis method system without diluting the first sample, the first analysis method system comprising (i) allowing the first sample to flow from the sample source along the continuous flow path to the analysis sample reservoir, and (ii) subsequently delivering the first sample from the analysis sample reservoir to the analysis device for spectral analysis.

[0030] In some embodiments, the method includes analyzing at least the first sample or the second sample among the one or more external samples by a second analysis method system while performing online dilution on the first sample or the second sample, the second analysis method system including (i) allowing the first sample or the second sample to flow from the sample source to the external sample reservoir, (ii) subsequently allowing the first sample or the second sample to flow from the external sample reservoir to the sample dilution junction, (iii) simultaneously allowing a diluent to flow to the sample dilution junction thereby diluting the first sample or the second sample to produce a diluted sample, (iv) allowing the diluted sample to flow from the sample dilution junction to the analysis sample reservoir, and (v) subsequently delivering the diluted sample from the analysis sample reservoir to the analysis device for spectral analysis.

[0031] In some such embodiments, the method may further include: determining a target dilution of the first sample based on a spectral analysis of the first sample obtained by the first analytical methodology; and analyzing the first sample by the second analytical methodology, wherein the first fluid pump and the second fluid pump of the sample delivery system are controlled so that the first sample and the diluent flow at relative flow rates suitable for achieving the target dilution in the diluted sample.

[0032] In other such embodiments, the method may further include: providing a calibration sample for analysis at the sample source, the calibration sample having one or more analytes with known concentrations; analyzing the calibration sample by the first analytical methodology, thereby delivering the calibration sample to the analytical device for spectral analysis; and analyzing the calibration sample one or more times by the second analytical methodology, thereby delivering one or more diluted calibration samples having one or more analytes with known concentrations to the analytical device for spectral analysis.

[0033] In some embodiments, the method includes: providing multiple external samples for analysis at the sample source; analyzing the multiple external samples by the first analysis method system; identifying any out-of-range samples in the multiple external samples having an analyte concentration greater than a predetermined maximum concentration based on spectral analysis of the multiple external samples; and if identified, analyzing the out-of-range samples by a second analysis method system while performing online dilution on the out-of-range samples, the second analysis method system including (i) flowing the out-of-range samples from the sample source to the external sample reservoir, (ii) subsequently flowing the out-of-range samples from the external sample reservoir to the sample dilution junction, (iii) simultaneously flowing a diluent to the sample dilution junction thereby diluting the out-of-range samples to produce a diluted sample having an analyte concentration less than the predetermined maximum concentration, (iv) flowing the diluted sample from the sample dilution junction to the analysis sample reservoir, and (v) subsequently delivering the diluted sample from the analysis sample reservoir to the analysis device for spectral analysis.

[0034] When the terms "comprise", "comprising" and "including" are used in the specification (including claims), they should be interpreted as indicating stated features, integers, steps or components, but not excluding the presence of one or more other features, integers, steps or components or combinations thereof.

[0035] As used herein, the terms "first," "second," "third," etc., in connection with various features of the disclosed apparatus are arbitrarily designated and are intended only to distinguish between two or more such features that the apparatus may incorporate in various embodiments. These terms themselves do not indicate any particular orientation or order. Furthermore, it should be understood that the presence of a "first" feature does not imply the presence of a "second" feature, the presence of a "second" feature does not imply the presence of a "first" feature, and so on.

[0036] Further aspects of the invention will appear from the detailed description of the invention which follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Embodiments of the invention will herein be described, by way of example only, with reference to the accompanying drawings, in which:

[0038] Figure 1 A sample delivery system 100 according to an embodiment of the present invention is schematically depicted, the sample delivery system comprising a valve assembly having three multi-port valves switchable between a first valve position and a second valve position. The first multi-port valve 104 is in its first valve position, the second multi-port valve 106 is in its first valve position, and the third multi-port valve 108 is in its first valve position.

[0039] Figure 2 The sample delivery system 100 is schematically depicted with the first multi-port valve 104 in its second valve position, the second multi-port valve 106 in its first valve position, and the third multi-port valve 108 in its first valve position.

[0040] Figure 3 The sample delivery system 100 is schematically depicted with the first multi-port valve 104 in its first valve position, the second multi-port valve 106 in its second valve position, and the third multi-port valve 108 in its second valve position.

[0041] Figure 4 The sample delivery system 100 is schematically depicted with the first multi-port valve 104 in its first valve position, the second multi-port valve 106 in its second valve position, and the third multi-port valve 108 in its first valve position.

[0042] Figure 5 The sample delivery system 100 is schematically depicted with the first multi-port valve 104 in its second valve position, the second multi-port valve 106 in its second valve position, and the third multi-port valve 108 in its second valve position.

[0043] Figure 6 A sample delivery system 200 according to an embodiment of the present invention is schematically depicted, the sample delivery system comprising a valve assembly having two multi-port valves. A first multi-port valve 204 switchable between a first valve position and a second valve position is in its first valve position. A second multi-port valve 206 switchable between a first valve position, a second valve position, and a third valve position is in its first valve position.

[0044] Figure 7 The sample delivery system 200 is schematically depicted with the first multi-port valve 204 in its second valve position and the second multi-port valve 206 in its first valve position.

[0045] Figure 8 The sample delivery system 200 is schematically depicted with the first multi-port valve 204 in its second valve position and the second multi-port valve 206 in its third valve position.

[0046] Fig. 9 The sample delivery system 200 is schematically depicted with the first multi-port valve 204 in its first valve position and the second multi-port valve 206 in its second valve position.

[0047] Fig.10A sample delivery system 300 according to an embodiment of the present invention is schematically depicted, the sample delivery system comprising a valve assembly having two multi-port valves. A first multi-port valve 204 switchable between a first valve position and a second valve position is in its first valve position. A second multi-port valve 206 switchable between a first valve position, a second valve position, and a third valve position is in its second valve position.

[0048] Fig.11 is a flow chart illustrating a method 1100 of performing analysis using a spectrometer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention relates to a sample delivery system for an analytical instrument. The sample delivery system includes a valve assembly, which includes one or more valves and is configured to receive an external sample from a sample source (such as an automatic sampler). The sample delivery system includes an external sample reservoir (for example, in the form of a sample loop), which is connected to a sample dilution junction via a valve assembly and is connected to the sample source in use. The valve assembly can be configured to alternatively allow (i) the flow of an external sample from a sample source to the external sample reservoir or (ii) the flow of an external sample from the external sample reservoir to the sample dilution junction. Therefore, representative aliquots of the external sample can be sequentially transferred to the external sample reservoir and then transferred out of the external sample reservoir. The sample delivery system includes: a first fluid pump, which is used to control the flow of an external sample from the external sample reservoir to the sample dilution junction; and a second fluid pump, which is used to control the flow of a diluent to the sample dilution junction, thereby diluting the external sample to produce a diluted sample.

[0050] The sample delivery system further comprises an analysis sample reservoir (e.g., in the form of a sample loop) configured to deliver the analysis sample contained therein to an analysis device of an analysis instrument. The analysis sample reservoir is coupled to the sample dilution junction via a valve assembly and is coupled to a sample source in use. The valve assembly may be configured to alternatively allow (i) flow of an external sample along a continuous flow path from the sample source to the analysis sample reservoir, thereby bypassing the external sample reservoir, or (ii) flow of a diluted sample from the sample dilution junction to the analysis sample reservoir. Valve components

[0051] The sample delivery system includes a valve assembly, and the valve assembly includes one or more valves, for example, two or more valves, such as two or three valves. In some embodiments, one or more valves in the valve are multi-port switching valves, which can be switched between at least two separated valve positions (for example, two or three valve positions) to reconfigure the internal flow channel of the valve between the ports of the valve. Suitable multi-port valves can be rotary switching valves including at least 4 and usually at least 5, 6 or 7 ports. In some exemplary embodiments, the valve assembly includes one or more seven-port rotary valves, for example, the Cheminert switching valve supplied by Valco Instruments Company Inc. (VICI). The valve assembly can include one or more other types of valves, for example, solenoid valves or stop valves. As will be appreciated by the technician, the valve assembly consistent with the principle disclosed herein can include a wide range of valve types and configurations.

[0052] The valve assembly is configured to receive an external sample from a sample source (such as an autosampler) and optionally deliver the sample (undiluted or diluted) via a nebulizer for analysis in an analytical device (e.g., an analytical device including a plasma source, such as in an ICP spectrometer). The valve assembly may include various fluid flow lines, including: (i) a sample source line coupled to a valve of the valve assembly, through which the external sample is received from the sample source; (ii) one or more sample transfer lines, each coupled to two valves of the valve assembly for transferring a sample or other fluid between the valves; and (iii) a sample delivery line coupled to a valve of the valve assembly, the sample delivery line for delivering the sample for analysis to the analytical device. The internal flow passages between these lines and the valve internal ports are typically narrow (e.g., 1 mm or 2 mm internal diameter) to allow fluid to flow through the valve assembly in a substantially plug flow pattern.

[0053] As used herein, when two components are "coupled," it means that the components are connected, directly or via other components, to allow fluid to flow therebetween, and provided that the valve assembly has been configured to allow such flow. External sample reservoir

[0054] The sample delivery system includes an external sample reservoir coupled to the sample dilution junction via a valve assembly. The valve assembly can be configured to alternatively allow (i) flow of an external sample from a sample source to the external sample reservoir (i.e., loading) or (ii) flow of an external sample retained in the external sample reservoir to the sample dilution junction (i.e., unloading).

[0055] As used herein, an external sample reservoir is adapted to receive and hold a representative aliquot of an external sample, the volume of the representative aliquot being sufficient to be transferred and subsequently diluted to a desired dilution level for analysis. Preferably, the external sample reservoir comprises a narrow fluid line (e.g., 1 mm or 2 mm inner diameter) having a length sufficient to provide the desired holding capacity, thereby allowing fluid to flow into and out of the external sample reservoir in a substantially plug flow pattern.

[0056] In some embodiments, the external sample reservoir is configured as a sample loop ("external sample loop") that is coupled to two ports of a multiport valve of a valve assembly. In this case, the external sample can be loaded into the external sample loop when the multiport valve is in one valve position, and delivered from the external sample loop to the sample dilution junction when the multiport valve is switched to another valve position. The flow of the external sample into the external sample loop can be driven by a fluid pump (e.g., a high-flow piston pump or a vacuum pump) or a vacuum source that is preferably located in the flow path to the drain (sample waste) downstream of the valve assembly.

[0057] Other configurations of the external sample reservoir can also be envisioned. For example, the external sample reservoir can include a pipeline that is connected to a multi-port valve of the valve assembly at only one end. Alternatively, the other end can be connected to a reversible fluid pump. In this case, the external sample can be loaded into the external sample reservoir and discharged from the external sample reservoir using a reversible fluid pump. A first fluid pump, a second fluid pump, and a sample dilution junction

[0058] The sample delivery system includes a first fluid pump and a second fluid pump to control the dilution degree of the external sample when dilution is required. The first fluid pump controls the flow of the external sample from the external sample reservoir to the sample dilution junction, and the second fluid pump controls the flow of the diluent from the diluent source to the sample dilution junction. The two independently controllable flows thus converge at the sample dilution junction, thereby diluting the external sample to produce a diluted sample.

[0059] In some embodiments, the first fluid pump causes the carrier fluid to flow through the external sample reservoir, thereby causing the external sample to flow ("push") from the external sample reservoir to the sample dilution junction. The use of a carrier fluid provides the advantage that the external sample never comes into contact with the first fluid pump. Alternatively, the system can be adapted to introduce gas bubbles to separate the carrier fluid from the external sample, thereby avoiding or acceptably limiting mixing between the two fluids.

[0060] In some embodiments, the second fluid pump is located upstream of the sample dilution junction, thus directly acting on the diluent when the diluent is made to flow from a diluent source (e.g., the internal volume of a tank or pump) through the second fluid pump to the sample dilution junction. However, the second fluid pump is not required to directly act on the diluent. For example, the second fluid pump can be located downstream of the sample dilution junction, and is preferably located downstream of the valve assembly in the flow path leading to the discharge port (sample waste). The second fluid pump directly acts on other fluids further downstream in the diluted sample or flow path, thus accurately controlling the total merged flow of the external sample and the diluent. The first fluid pump only accurately controls the flow velocity of the external sample. Thus, the diluent is extracted to the sample dilution junction with the required flow velocity (i.e., as the difference between the flow velocity of the first fluid pump and the second fluid pump). In this way, the second fluid pump indirectly controls the flow of the diluent to the sample dilution junction.

[0061] It will also be understood that the first fluid pump can be located downstream to accurately control the total combined flow of the external sample and diluent, while the second fluid pump accurately controls only the diluent flow. Thus, the first fluid pump indirectly controls the flow of the external sample to the sample dilution junction. In all cases, the sample delivery system must remain appropriately configured to allow the initial transfer of the external sample from the sample source to the sample reservoir prior to a subsequent dilution step in which the first fluid pump and the second fluid pump operate as described herein.

[0062] The first fluid pump and the second fluid pump can be syringe pumps or other positive displacement pumps (such as piston pumps) appropriately, and it is possible to accurately control the fluid flow rate within the required range. Alternatively, the pump can be used in combination with a flow meter to accurately control flow. In some embodiments, the first fluid pump and the second fluid pump are configured to make an external sample and a diluent flow with a relative flow rate (v / v) in the range of from 10:1 to 1:1000 (such as in the range of from 1:1 to 1:400, such as from 1:1 to 1:250). In some embodiments, the first fluid pump and the second fluid pump are configured to make the external sample and the diluent flow with a combined flow rate between 2ml / min and 20ml / min (preferably between 5ml / min and 15ml / min, such as about 10ml / min).

[0063] The controlled flows of the external sample and the diluent converge at the sample dilution junction, so that the external sample is diluted to produce a diluted sample with a desired dilution level. The sample dilution junction can optionally be internal to a multi-port valve of a valve assembly, for example, at a port of the valve, such as where two internal flow channels passing through the valve converge. However, any sample dilution junction configuration that enables the two flows to converge and then mix is ​​contemplated. Analytical sample reservoir

[0064] The sample delivery system comprises an analysis sample reservoir configured to deliver the analysis sample contained therein to an analysis device. The analysis sample reservoir is coupled to a sample dilution junction via a valve assembly and, at least in use, to a sample source, and the valve assembly is configurable to alternatively allow (i) flow of an external sample along a continuous flow path from the sample source to the analysis sample reservoir, thereby bypassing the external sample reservoir (i.e., loading an undiluted analysis sample), or (ii) flow of a diluted sample from the sample dilution junction to the analysis sample reservoir (i.e., loading a diluted analysis sample).

[0065] As used herein, an analytical sample reservoir is adapted to receive and hold a representative aliquot of a diluted or undiluted sample, the volume of the representative aliquot being sufficient to be subsequently transferred to an analyzer (e.g., via a nebulizer) for spectroscopic analysis. Preferably, the analytical sample reservoir comprises a narrow fluid line (e.g., 1 mm or 2 mm inner diameter) having a length sufficient to provide the required holding capacity, thereby allowing fluid to flow into and out of the analytical sample reservoir in a substantially plug flow pattern.

[0066] The flow of the external sample along the continuous flow path from the sample source to the analytical sample reservoir can be driven by a fluid pump (e.g., a high flow rate piston pump or a vacuum pump) or a vacuum source preferably located downstream of the analytical sample reservoir in the flow path leading to the exhaust port (sample waste). The flow of the diluted sample from the sample dilution junction to the analytical sample reservoir is driven by the first fluid pump and the second fluid pump.

[0067] In some embodiments, the analysis sample reservoir is configured as a sample loop ("analysis sample loop") that is coupled to two ports of a multiport valve of a valve assembly. In this case, the analysis sample can be loaded into the analysis sample loop when the multiport valve is in one valve position, and delivered from the analysis sample loop to the analysis device when the multiport valve is switched to another valve position. Optionally, a fluid pump can be provided to cause the carrier fluid to flow directly through the multiport valve to the analysis device when the multiport valve is in a first valve position, and to divert the carrier fluid to pass through the analysis sample loop when the multiport valve is switched to a second valve position. This delivers ("pushes") the analysis sample from the analysis sample loop to the analysis device without interrupting the continuous flow of the liquid to the analyzer. Optionally, the system may include a bubble injector for injecting gas bubbles to space the carrier fluid from the analysis sample.

[0068] Other configurations of the analytical sample reservoir are also contemplated. For example, the analytical sample reservoir may include a pipeline that is coupled to a multi-port valve of a valve assembly at only one end. The other end may be coupled to a reversible fluid pump. In this case, the analytical sample may be loaded into and discharged from the analytical sample reservoir using the reversible fluid pump.

[0069] The feature of the sample delivery system disclosed herein is that the external sample stored in the external sample reservoir is always diluted when being transferred to the analysis sample reservoir during normal operation. Therefore, the external sample reservoir can have a smaller volume (sample holding capacity) than if the representative external sample is transferred to the analysis sample reservoir without dilution. As an example, the external sample reservoir and the analysis sample reservoir can be approximately equal in size. If the minimum dilution ratio is 1: 1, this provides a sufficient volume of diluted sample to rinse the analysis sample loop and leave a representative aliquot of the diluted sample in the analysis sample loop. Advantageously, the analysis sample system therefore does not require more samples than other comparable sample delivery systems with analysis sample reservoirs but without online dilution capabilities. Sample source

[0070] The sample delivery system may include a sample source for providing one or more external samples for analysis. As used herein, an external sample is a sample provided outside and upstream of the sample delivery system. The sample source may be permanently or removably coupled to the valve assembly via a sample source line. In use, the sample source is located upstream of all valves of the valve assembly, and specifically it is not coupled to an online sample loop of a valve of the valve assembly.

[0071] The sample source can be an autosampler adapted to sequentially sample a plurality of separate external samples (e.g., in sample vials) provided for analysis. Optionally, such an autosampler can also include a cleaning fluid source that can be used to flush the valve assembly and any sample reservoir in various operating modes.

[0072] However, it will be understood that the sample source can in principle be any vessel or device that can provide an external sample for analysis via a valve assembly. For example, an analytical instrument (such as an ICP spectrometer) can be integrated into an industrial process for online monitoring purposes, and in this case, the sample source can take the form of an automated interface comprising one or more pumps, selection valves, etc. and adapted to sample the process fluid. The automated interface can even subject the primary sample to one or more sample preparation processes, including (but not limited to) digestion and reagent addition, thereby providing a pre-treated external sample for transfer to the valve assembly of the sample delivery system. Exemplary embodiments

[0073] exist Figures 1 to 5 A sample delivery system 100 according to an embodiment of the present invention is depicted in . System 100 includes a valve assembly 102, the valve assembly including a first multi-port valve 104, a second multi-port valve 106, and a third multi-port valve 108, each of which can be switched between a first valve position and a second valve position, and the three internal flow channels of the valve in the first valve position and the second valve position provide different connection combinations between the two ports of the valve. Multi-port valves 104, 106, and 108 can each be a seven-port rotary valve. The second multi-port valve 106 does not utilize all seven ports, and the unutilized ports 1 and 7 are simply blocked. Alternatively, valve 106 can be a customized five-port valve.

[0074] The first multi-port valve 104 is coupled to an analytical sample loop 110, which is connected to port 1 and port 4 of the valve 104. The analytical sample loop 110 includes a coil of small diameter tubing (e.g., 1 mm or 2 mm inner diameter) having a sufficient volume (depending on the application, e.g., 0.25 ml to 4 ml, such as 1 ml to 2 ml) to accommodate an analytical sample for subsequent analysis in an analytical device 124. The valve 104 is also coupled to a second multi-port valve 106 via a loading line 112, which is connected to port 6 of the valve 104 and port 4 of the valve 106. When the first multi-port valve 104 is in its first valve position, as shown in FIG. Figure 1 As depicted, analytical sample may be loaded into analytical sample loop 110 by flowing an undiluted or diluted sample to be analyzed from loading line 112 through analytical sample loop 110 and out of port 5 of valve 104 to exhaust line 113, wherein flow continues at least until analytical sample loop 110 contains a representative sample.

[0075] The system 100 further comprises a third fluid pump 114 to flow a first carrier fluid 116 (also referred to as a cleaning fluid) to the first multi-port valve 104 via a carrier fluid line 118 connected to port 3 of the valve 104. The third fluid pump 114 may be a peristaltic pump configured to deliver a substantially constant flow rate of carrier fluid in use (depending on the application, e.g., 0.3 ml / min for ICP-MS and 1 ml / min for ICP-OES). When the first multi-port valve 104 is in its first valve position, as shown in FIG. Figure 1 As depicted, pump 114 causes a first carrier fluid 116 to flow directly through valve 104, exit via port 2, and then proceed to nebulizer 122 via sample delivery line 120. The nebulized droplets may then be sorted in a spray chamber (not shown) and sent to an analytical device 124 (e.g., an ICP-OES or ICP-MS analyzer).

[0076] Once the analytical sample representing the undiluted or diluted sample to be analyzed has been loaded into the analytical sample loop 110, the analytical sample is delivered to the nebulizer 122 via the sample delivery line 120 by switching the first multi-port valve 104 to its second valve position, as shown in FIG. Figure 2 Thus, the flow of the first carrier fluid 116 is diverted through the analytical sample loop 110 , pushing the analytical sample out of the valve 104 via the sample delivery line 120 to the nebulizer 122 where it is atomized and subsequently analyzed in an analytical device 124 .

[0077] The system 100 may optionally include a bubble injector 126 configured to inject a gas bubble (e.g., pressurized argon) into the carrier fluid line 118 immediately before the carrier fluid line connects to port 3 of the valve 104. The bubble is injected when the first multi-port valve 104 is switched to its second valve position to divert the first carrier fluid 116 through the analytical sample loop 110. Thus, the bubble physically separates the first carrier fluid 116 from the analytical sample as the carrier fluid flows through the analytical sample loop and pushes the analytical sample to the nebulizer 122. This prevents or mitigates any undesirable dilution of the analytical sample as it is carried to the nebulizer 122.

[0078] The system 100 may further include a fifth fluid pump 128 (optionally also a peristaltic pump) to flow the internal standard 130 to the sample delivery line 120. Typically, the pumps 114 and 128 are two channels of a single peristaltic pump unit, which advantageously ensures a consistent ratio of the flow of the internal standard 30 and the first carrier fluid 116. Regardless of whether the valve 104 is in its first valve position or its second valve position, the flow of the internal standard 130 can be directed through the first multi-port valve 104, into port 7 and out of port 2, as shown. Figure 1 and Figure 2 The internal standard is thus mixed with the flow of the first carrier fluid 116 and / or the analytical sample before it reaches the nebulizer 122. Alternatively, the flow of the internal standard 130 may be joined to the sample delivery line 120 downstream of the valve 104.

[0079] The system 100 is configured to deliver a substantially continuous flow of liquid to the nebulizer 122, the flow of liquid being set by the combined flow rates of the third fluid pump 114 and the fifth fluid pump 128 (if present), despite discontinuity in the delivery of the analytical sample from the analytical sample loop 110. This arrangement is particularly desirable when the analytical device 124 includes a plasma source for sample processing, as the constant flow of liquid helps maintain the stability of the plasma flame.

[0080] like Figure 1As depicted, the system 100 is configured such that an undiluted or diluted sample to be analyzed is loaded into the analysis sample loop 110 via port 1 and is delivered out of port 1 for analysis ("last in, first out"). Alternatively, the loading line 112 may be connected to port 5 and the drain line 113 connected to port 6 of the valve 104, such that the fluid to be analyzed is loaded into the analysis sample loop 110 via port 4 but is still delivered out of port 1 for analysis ("first in, first out").

[0081] The second multi-port valve 106 is coupled to the third multi-port valve 108 via a sample transfer line 132, which is connected to port 5 of the valve 106 and port 6 of the valve 108. The third multi-port valve 108 is coupled to a sample source 134 via a sample source line 136, which is connected to port 5 of the valve 108. The sample source 134 is configured to provide one or more external samples for analysis, and may be an autosampler adapted to sequentially sample a plurality of separate external samples (e.g., in sample vials) provided for analysis. However, the sample source 134 is not limited thereto, and may be, for example, an automated interface for periodic online monitoring of a process fluid (e.g., a process stream from an industry or food processing).

[0082] like Figure 1 As depicted, the first multi-port valve 104, the second multi-port valve 106, and the third multi-port valve 108 are each in their first valve positions. The valve assembly 102 is thus configured to allow flow of an external sample along a continuous flow path from the sample source 134 to the analytical sample loop 110 (via the sample source line 136, the valve 108, the sample transfer line 132, the valve 106, the loading line 112, and the valve 104).

[0083] The system 100 includes a fourth fluid pump 142 that is located downstream of the first multi-port valve 104 and in the flow path between the valve 104 and the exhaust port 140 when the bypass valve 138 is in the first configuration. The fourth fluid pump 142 may be a high flow rate piston pump or a vacuum pump (depending on the flow rate of the application, e.g., 0 ml / min to 50 ml / min). Figure 1 When configured as depicted, the fourth fluid pump 142 can thus be operated to cause the external sample (e.g., at a flow rate of about 30 ml / min) to flow directly from the sample source 134 through the sample loop 110 and onward to the exhaust port 140 until an analytical sample representing the external sample has been loaded into the sample loop 110. Alternatively, a vacuum source can be used in place of the fourth fluid pump 142 to draw the external sample through the sample loop 110. In either case, the analytical sample so loaded can then be analyzed by switching the first multi-port valve 104 to the second valve position, as described herein and Figure 2 Depicted.

[0084] With both valves 106 and 108 maintained in their first valve positions, as Figure 1 and Figure 2 As depicted, one or more samples provided at the sample source 134 can thus be analyzed without in-line dilution, as described herein. Due to the continuous flow path from the sample source 134 to the analysis sample loop 110, the one or more external samples advantageously flow directly to the analysis sample loop without passing through the dilution module, thus minimizing the time required for each analysis.

[0085] However, system 100 may also be configured to allow for on-line dilution of one or more samples provided at sample source 134 to, for example, an instrument-required dilution level determined based on an initial analysis of an undiluted external sample as described herein.

[0086] Thus, the third multi-port valve 108 is coupled to an external sample reservoir 144, which is configured as a sample loop connected to port 1 and port 4 of the valve 108. The sample loop may include a coil of thin tubing (e.g., 1 mm or 2 mm inner diameter) having sufficient volume to accommodate the external sample for subsequent dilution and analysis in the analysis device 124. When the third multi-port valve 108 and the second multi-port valve 106 are switched to their second valve positions, as shown in FIG. Figure 3 As depicted, the external sample may be loaded into the external sample reservoir 144 by allowing the fourth fluid pump 142 to flow the external sample (e.g., at a flow rate of about 30 ml / min) from the sample source 134 via the sample source line 136, the external sample reservoir 144, the sample transfer line 132, the valve 106, and the exhaust line 148 to the exhaust port 140, wherein the flow continues at least until the external sample reservoir 144 contains a representative sample of the external sample. The valve assembly 102 may thus be configured to allow the fourth fluid pump 142 to flow the external sample from the sample source 134 to the external sample reservoir 144.

[0087] The system 100 includes a first fluid pump 150 to flow a second carrier fluid 152 to the third multi-port valve 108 via a carrier fluid line 154, entering at port 3. The system 100 also includes a second fluid pump 156 to flow a diluent 158 ​​to the third multi-port valve 108 via a diluent fluid line 160, entering at port 7 and exiting at port 2, regardless of whether the valve 108 is in its first valve position or its second valve position. Figure 3 and Figure 4A first fluid pump 150 and a second fluid pump 156, which may suitably be syringe pumps or other positive displacement pumps such as piston pumps, are configured to accurately control the relative flow rates of a second carrier fluid 152 and a diluent 158 ​​to achieve a target dilution of an external sample contained in an external sample reservoir 144.

[0088] In one implementation, the first fluid pump 150 may be controlled within a flow rate range between 0.04 ml / min and 5.0 ml / min, and the second fluid pump 156 may be controlled within a flow rate range between 5.0 ml / min and 9.96 ml / min, thereby providing a dilution factor in the range of 2 to 250 at a constant combined flow rate of 10 ml / min. In such an implementation, it has been found that due to the minimum dilution factor of 2, the volume of the external sample reservoir 144 can be approximately equal to the volume of the analytical sample loop 110 (and can even be slightly smaller). In contrast, for prior art designs that cannot bypass the dilution module, a significantly larger first sample loop would be required because the size of the first sample loop needs to be determined to transfer the undiluted sample to the analytical sample loop. Therefore, the present invention advantageously allows a smaller volume of external sample to be loaded into the external sample reservoir 144 more quickly than is possible with prior art designs, the degree of advantage corresponding to the minimum dilution factor.

[0089] The system 100 may include only a single first fluid pump 150 and a single second fluid pump 156, as depicted in the figure, but it will be appreciated that the system 100 may alternatively include two or more first fluid pumps 150 and / or two or more second fluid pumps 156 arranged in parallel and having different flow rate ranges. This may advantageously expand the range of relative flow rates (v / v) of the second carrier fluid 152 and the diluent 158 ​​that may be delivered, thereby allowing a wider range of sample dilutions to be achieved. The first fluid pump 150 and the second fluid pump 156 may obtain the second carrier fluid 152 and the diluent 158 ​​from a single diluent source 162, such as Figure 3 and Figure 4 As depicted, and in fact the first carrier fluid 116 may also be obtained from the same source. However, it will be appreciated that the second carrier fluid 152, the diluent 158 ​​and the first carrier fluid 116 may in principle each be obtained from different sources and have different compositions.

[0090] Once the external sample reservoir 144 contains the representative external sample loaded from the sample source 134, the third multi-port valve 108 is switched back to its first valve position, such as Figure 4The first fluid pump 150 is activated to flow the second carrier fluid 152 through the external sample reservoir 144 at a predetermined flow rate, thereby pushing the external sample out of the valve 108, exiting through port 2 and into the diluted sample transfer line 146. The second fluid pump 156 is activated to flow the diluent 158 ​​through the valve 108, exiting through port 2 and into the diluted sample transfer line 146. Port 2 of the valve 108 thus operates as a sample dilution junction 164, wherein the external sample contacts and mixes with the diluent 158 ​​to produce a diluted sample, the dilution level of which is controlled by the relative flow rates of the second carrier fluid 152 and the diluent 158.

[0091] The system 100 can be configured to introduce gas bubbles (e.g., air 166) to isolate the second carrier fluid 152 from the external sample as the second carrier fluid 152 flows through the external sample reservoir 144. For example, when both valves 108 and 106 are in their second valve positions (e.g., Figure 3 After flushing the second carrier fluid 152 and diluent 158 ​​through both valves at the time of the second multi-port valve 106 (as depicted), the second multi-port valve 106 is switched to its first valve position and the flow directions of the first fluid pump 150 and the second fluid pump 156 are reversed. Thus, air 166 is drawn into the dilution sample transfer line 146 via the gas inlet 168, wherein the liquid continues to flow in the reverse direction until the air is just drawn into the carrier fluid line 154 and the dilution fluid line 160, i.e., until the gas bubble just passes through ports 3 and 7 of the valve 108, respectively. Thus, as the carrier fluid flows through the external sample reservoir 144 and pushes the external sample to the sample junction 164, the resulting air bubble physically separates the second carrier fluid 152 from the sample (one ahead of the diluted sample and one behind the external sample). This prevents or mitigates any undesirable dilution of the external sample before the intended dilution occurs at the sample dilution junction 164.

[0092] like Figure 3 and Figure 4 As depicted, the system 100 is configured such that an external sample is loaded into the external sample reservoir 144 via port 4 and is delivered out of port 1 to the sample dilution junction 164 ("first in, first out"). Alternatively, the sample source line 136 may be connected to port 6, and the sample transfer line 132 connected to port 5 of the valve 108, such that an external sample is loaded into the analytical sample loop 110 via port 1 and is delivered out of port 1 to the sample dilution junction 164 ("last in, first out").

[0093] Continue to refer to Figure 4, the diluted sample generated at the sample dilution junction 164 flows through the analysis sample loop 110 to the exhaust port 140 via the valve 106 (in its second valve position) and the loading line 112, wherein the flow continues at least until the analysis sample loop 110 contains a representative sample of the diluted sample. The fourth fluid pump 142 is preferably bypassed by switching the bypass valve 138 to its second configuration, as the flow is not required and may interfere with the accurate operation of the pumps 150 and 156.

[0094] The analytical sample thus loaded into the analytical sample loop 110 is then delivered to the nebulizer 122 via the sample delivery line 120 by switching the first multiport valve 104 to its second valve position, as shown in FIG. Figure 5 With valve 108 in its second valve position, Figure 5 , the external sample reservoir 144 can then be flushed with a rinse fluid provided via the sample source line 136 (e.g., from an autosampler) during the analysis step. The external sample reservoir 144 can then be reloaded with the external sample from the sample source 134, thereby facilitating a rapid turnaround between successive online dilution analyses. Optionally, the flow of the second carrier fluid 152 and / or diluent 158 ​​can continue while the diluted sample is being analyzed, thereby flushing the diluted sample out of the flow path from the sample dilution junction 164 to the exhaust port 140. If desired, the pumps 150 and 156 can also be refilled with the second carrier fluid 152 and the diluent 158 ​​from the diluent source 162 during the analysis step.

[0095] Thus, if necessary, the system 100 allows the external sample provided by the sample source 134 to be accurately diluted online. The online dilution is performed through a three-stage process (i.e., stage 1: loading the external sample into the external sample reservoir 144; stage 2: unloading the external sample reservoir, diluting the sample and reloading it into the analysis sample loop 110; and stage 3: unloading the diluted sample to the analysis device 124). This necessarily increases the time spent on each analysis. However, as described herein, the system 100 is advantageously configured so that samples that do not require dilution or require initial analysis without dilution can be analyzed in only two stages by bypassing the dilution module including the external sample reservoir 144, thereby improving instrument productivity.

[0096] exist Figures 6 to 9200 according to an embodiment of the present invention. System 200 includes a valve assembly 202, which includes a first multi-port valve 204 and a second multi-port valve 206. Valve 204 is switchable between a first valve position and a second valve position, in which three internal flow channels of the valve provide different connection combinations between two ports of the valve. Valve 206 has two internal flow channels (in Figure 6-Figure 9 The invention also provides a first valve position and a second valve position, wherein the flow channel provides different connection combinations between the ports.

[0097] The first multi-port valve 204 is coupled to an analytical sample loop 210, which includes a coil of small diameter tubing having sufficient volume to contain an analytical sample for subsequent analysis in an analytical device 224. The valve 204 is also coupled to a second multi-port valve 206 via a loading line 212. When the first multi-port valve 204 is in its first valve position, as shown in FIG. Figure 6 As depicted, analytical sample may be loaded into analytical sample loop 210 by flowing an undiluted or diluted sample to be analyzed from loading line 212 through analytical sample loop 210 and out of valve 204 to exhaust line 213, wherein flow continues at least until analytical sample loop 210 contains a representative sample.

[0098] The system 200 further includes a third fluid pump 214 (e.g., a peristaltic pump) to flow a first carrier fluid 216 (also referred to as a cleaning fluid) to the first multi-port valve 204 via a carrier fluid line 218. When the first multi-port valve 204 is in its first valve position, as shown in FIG. Figure 6 As depicted, pump 214 causes a first carrier fluid 216 to flow directly through valve 204 and to nebulizer 222 via sample delivery line 220 .

[0099] Once the analytical sample representing the undiluted or diluted sample to be analyzed has been loaded into the analytical sample loop 210, the analytical sample is delivered to the nebulizer 222 via the sample delivery line 220 by switching the first multi-port valve 204 to its second valve position, as shown in FIG. Figure 7 Thus, the flow of the first carrier fluid 216 is diverted through the analytical sample loop 210, pushing the analytical sample out of the valve 204 via the sample delivery line 220 to the nebulizer 222 where it is atomized and subsequently analyzed in an analytical device 224 (e.g., an ICP-OES or ICP-MS analyzer).

[0100] As with system 100, system 200 may optionally include a bubble injector (not shown) configured to inject spacer gas bubbles into carrier fluid line 218 just prior to its connection with 204, and a fluid pump to flow an internal standard into sample delivery line 220 (also not shown). Analysis sample loop 210 may be appropriately configured for last-in, first-out or first-in, first-out operation.

[0101] The second multi-port valve 206 is coupled to a sample source 234 via a sample source line 236. The sample source 234 is configured to provide one or more external samples for analysis and may be an autosampler or other sample delivery device as disclosed herein. Figure 6 As depicted, the first multi-port valve 204 and the second multi-port valve 206 are each in their first valve positions. The valve assembly 202 is thus configured to allow flow of an external sample along a continuous flow path from the sample source 234 to the analytical sample loop 210 (via the sample source line 236, the valve 206, the loading line 212, and the valve 204).

[0102] The system 200 includes a fourth fluid pump 242 (suitably a high flow rate piston pump or a vacuum pump) located downstream of the first multi-port valve 204 and in the flow path between the valve 204 and the exhaust port 240. The fourth fluid pump 242 can thus be operated to cause the external sample to flow directly from the sample source 234 through the sample loop 210 and onward to the exhaust port 240 until an analytical sample representing the external sample has been loaded into the sample loop 210. The analytical sample so loaded can then be analyzed by switching the first multi-port valve 204 to the second valve position, as described herein and Figure 7 Depicted.

[0103] With valve 206 maintained in its first valve position, as Figure 6 and Figure 7 As depicted, one or more samples provided at the sample source 234 can thus be analyzed without in-line dilution, as described herein. Due to the continuous flow path from the sample source 234 to the analysis sample loop 210, the one or more external samples advantageously flow directly to the analysis sample loop without passing through the dilution module, thus minimizing the time required for each analysis.

[0104] However, system 200 may also be configured to allow for on-line dilution of one or more samples provided at sample source 234 to, for example, an instrument-required dilution level determined based on an initial analysis of an undiluted external sample as described herein.

[0105] Thus, the second multi-port valve 206 is coupled to an external sample reservoir 244, which in the system 200 is not configured as a sample loop connected to two ports of a multi-port valve, but rather as a line coupled to the second multi-port valve 206 at one end and to a switching valve 251 and a first fluid pump 250 at the other end. When the switching valve 251 is configured to connect the pump 250 to the external sample reservoir 244 (as seen in the figure), the pump 250 is capable of flowing fluid in two directions: from the valve 206 to fill the external sample reservoir 244; and inversely thereto, to accurately control the flow of an external sample from the external sample reservoir 244 for dilution. Thus, the pump 250 can be a syringe pump or other positive displacement pump (such as a piston pump) that can accurately control the fluid flow rate within a desired range. The external sample reservoir 244 can include a coil of small diameter tubing (e.g., an inner diameter of 1 mm or 2 mm) with sufficient volume to accommodate an external sample for subsequent dilution and analysis in the analysis device 224.

[0106] Preferably, the external sample to be diluted and analyzed does not contact the pump 250 during loading and unloading of the external sample reservoir 244, thereby avoiding contamination of the sample. Therefore, in some embodiments, the pump 250 can be operated with the carrier fluid in its internal volume, which has the additional advantage of minimizing contamination of the pump. For example, in the case where the second multi-port valve 206 is switched to its third valve position (such as Figure 8 244 into its internal volume (optionally, as desired, excess carrier fluid is discharged to drain port 241 by reconfiguring switching valve 251). Alternatively, diluent 258 may be used to fill external sample reservoir 244 and pump 250 (with valve 206 in its first position, as in Figure 7 ).

[0107] With the second multi-port valve 206 in its third valve position, the pump 250 may be used to load the external sample from the sample source 234 via the sample source line 236 into the external sample reservoir 244. Preferably, the carrier fluid previously loaded into the external sample reservoir 244 is thus drawn into the interior volume of the first fluid pump 250, where the flow stops before the external sample enters the switching valve 251. Optionally, a spacer gas bubble may be introduced to space the external sample from the carrier fluid, thereby avoiding or acceptably limiting mixing between the two fluids and ensuring that the external sample reservoir 244 contains a representative aliquot of the external sample. The valve assembly 202 may therefore be configured to allow the first fluid pump 250 to flow the external sample from the sample source 234 to the external sample reservoir 244.

[0108] Optionally, an external sample may be loaded into the external sample reservoir 244 while the analysis sample previously loaded into the analysis sample loop 210 is being analyzed. Thus, the multi-port valve 204 may be maintained in its second valve position (e.g., Figure 8 ), and when the external sample reservoir 244 is loaded with a new external sample, the analysis sample loop 210 and the nebulizer can be flushed using a continuous flow of the first carrier fluid 216 to the nebulizer. The valve 204 can then be switched to its first valve position, ready to load another analysis sample.

[0109] Once the external sample reservoir 244 contains a representative external sample loaded from the sample source 234, the second multi-port valve 206 is switched to its second valve position and the first multi-port valve 204 is switched to its first valve position (if not already done), as shown. Fig. 9 Depicted. The first fluid pump 250 is started so that the external sample flows back to the valve 206 from the external sample reservoir 244, and the external sample is typically pushed out using the carrier fluid inside the pump. The pump 250 is designed so that the reverse flow toward the valve 206 required for dilution from the external sample reservoir 244 never exceeds its internal volume. The second fluid pump 256 (suitably, alternatively, the injection pump that can be connected to the source of the valve 206 or the diluent 258 via the switching valve 257) is started so that the diluent 258 flows to the valve 206, and the diluent contacts and dilutes the flow of the external sample at the sample dilution junction 264 inside the valve 206, to produce a diluted sample. The first fluid pump 250 and the second fluid pump 256 are configured to accurately control the relative flow rate of the external sample and the diluent 258 from the external sample reservoir 244 to achieve the target dilution.

[0110] The system 200 may optionally be configurable to introduce one or more spacer gas bubbles, for example, bubbles from the dilution line 260 to precede the diluted sample and / or bubbles trailing the undiluted external sample to separate it from the liquid in the pump 250 .

[0111] Continue to refer to Fig. 9 The diluted sample produced at the sample dilution junction 264 flows through the analytical sample loop 210 via the loading line 212 to the exhaust port 240 (preferably via, for example, a one-way valve 238 or alternatively, such as Figure 1-Figure 5 The analytical sample loop 210 is then switched to bypass the fourth fluid pump 242 by switching the first multi-port valve 204 to its second valve position, wherein the flow continues at least until the analytical sample loop 210 contains a representative sample of the diluted sample. Simultaneously, the first carrier fluid (also referred to as a wash fluid) flows directly to the nebulizer 222 through the valve 204. The analytical sample thus loaded into the analytical sample loop 210 is then delivered to the nebulizer 222 via the sample delivery line 220 by switching the first multi-port valve 204 to its second valve position, as described herein.

[0112] Optionally, the flow of diluent 258 may continue while the diluted sample is being analyzed for a time sufficient to flush the remaining diluted sample out of the flow path from sample dilution junction 264 to drain 240. The valve 206 is then switched to its third valve position (again as shown in FIG. Figure 8 ), the external sample reservoir 244 may then be flushed with a rinse fluid (e.g., from an autosampler) provided via the sample source line 236. The external sample reservoir 244 may then be reloaded with the external sample from the sample source 234, thereby facilitating a rapid turnaround between successive online dilution analyses. Alternatively, the valve 206 may be switched to its first valve position (again as shown in Figure 7 ), the loading line 212 may then be flushed with a rinse fluid (e.g., from an autosampler) provided via the sample source line 236 in preparation for subsequent analysis with or without dilution. The external sample reservoir 244 may also be flushed with a diluent 258, e.g., when the sample is analyzed without dilution, as described herein with reference to Figure 6 and Figure 7 as described.

[0113] Thus, if desired, the system 200 allows for accurate online dilution of external samples provided by the sample source 234 in a dilution module including the external sample reservoir 244. This necessarily increases the time taken for each analysis. However, as described herein, the system 200 is advantageously configured such that samples that do not require dilution or require initial analysis without dilution can bypass the external sample reservoir 144, thereby increasing instrument productivity.

[0114] exist Fig.10 200 . A sample delivery system 300 according to an embodiment of the present invention is depicted in FIG. System 300 is a variation of system 200 in which fluid pump 256 for pumping diluent 258 is absent. When an online dilution of the sample is desired, the external sample is loaded into external sample reservoir 244 as described herein for system 200. The second multi-port valve 206 is then switched to its second valve position, and the first multi-port valve is switched to its first valve position (if not already done), as shown in FIG. Fig.10Depicted. The first fluid pump 250 is activated to flow the external sample from the external sample reservoir 244 back to the valve 206. The fluid pump 242 (operating here in place of the second fluid pump 256) is activated to flow the diluted sample from the sample dilution junction 264 through the analysis sample loop 210 to the exhaust port 240 via the loading line 212. The fluid pump 242 accurately controls the total flow rate of the diluted sample, while the first fluid pump 250 accurately controls the external sample flow rate. Therefore, the diluent 258 is drawn to the sample dilution junction 264 at the desired flow rate (i.e., the difference between the flow rates of the pumps 242 and 250). In this way, the fluid pump 242 indirectly controls the flow of the diluent 258 to the sample dilution junction, and thus controls the dilution level of the diluted sample loaded into the analysis sample loop 210.

[0115] In system 300, fluid pump 242 thus serves two main functions: (1) loading external sample into analysis sample loop 210 (when analyzing undiluted samples), which is preferably fast but not necessarily accurate; and (2) controlling the flow of diluent (when analyzing diluted samples), which is typically slower but must be accurate. Therefore, pump 242 is optionally implemented as two pumps in parallel to best achieve both purposes.

[0116] In another envisioned variation of system 200 (not shown), the analysis sample loop 210 is replaced by an analysis sample reservoir in the form of a pipeline connected to valve 204 at one end and to a first fluid pump 242 at the other end. Thus, the diluted or undiluted sample to be analyzed is pumped into the analysis sample reservoir by pump 242. When the resulting representative analysis sample is to be analyzed, pump 242 reverses direction (while switching valve 204) so ​​that the analysis sample flows to analyzer 224. In this embodiment, pump 242 is designed so that the reverse flow to the analyzer never exceeds its internal volume, thereby not requiring a carrier fluid to transport the analysis sample from the analysis sample reservoir for analysis. Therefore, in this embodiment, the analysis sample reservoir has a design and operation similar to that of the external sample reservoir 244. Spectrometer

[0117] The present invention also relates to a spectrometer comprising an analytical device and a sample delivery system as disclosed herein. The analytical device can be permanently or removably connected to the sample delivery line of the analytical sample device. In some embodiments, the analytical device is a conventional analytical device for a plasma spectrometer, and therefore includes components such as a nebulizer, a spray chamber for classifying aerosolized samples, a plasma torch (optionally powered by an RF generator), and an optical or ion mass detector. The spectrometer can be an ICP-OES and / or ICP-MS spectrometer. Alternatively, it can be a microwave plasma spectrometer.

[0118] A computing device may be provided to control the operation of the spectrometer. The computing device may include one or more tangible non-transitory computer-readable media having computer-executable instructions for executing a computer-implemented method to control the operation of the spectrometer according to the principles disclosed herein. Typically, the computer-implemented method is automatically executed on a computer processor, which is provided together with or separately from the spectrometer. The computer processor may include a software application installed thereon for executing one or more steps of the computer-implemented method. In alternative embodiments, the software application may be a cloud-based application accessible via a network such as the Internet. In some embodiments, the software application may be remotely accessed via a local network.

[0119] In some embodiments, the spectrometer controlled by the computing device is thus adapted to deliver an external sample for spectroscopic analysis by method (a) or method (b). Method (a) is a computer-implemented method for spectroscopic analysis of an external sample without online dilution, and method (b) is a computer-implemented method for spectroscopic analysis of an external sample with online dilution.

[0120] Method (a) comprises: (i) flowing the external sample along a continuous flow path from a sample source to an analytical sample reservoir without diluting the external sample; and (ii) The external sample is then delivered from the analytical sample reservoir to the analytical device for spectroscopic analysis.

[0121] Method (b) comprises: (i) flowing an external sample from a sample source to an external sample reservoir; (ii) subsequently flowing the external sample from the external sample reservoir to the sample dilution junction; (iii) simultaneously flowing a diluent to the sample dilution junction, thereby diluting the external sample to produce a diluted sample; (iv) flowing the diluted sample from the sample dilution junction to the analytical sample reservoir; and (v) The diluted sample is then delivered from the analytical sample reservoir to an analytical device for spectroscopic analysis.

[0122] In some embodiments, a spectrometer controlled by a computing device is adapted to: deliver an external sample for spectral analysis by method (a), thereby determining a target dilution of the external sample based on the spectral analysis of the external sample in method (a); and deliver a diluted sample comprising a first external sample and a diluent for spectral analysis by method (b). The first fluid pump and the second fluid pump of the sample delivery device are therefore controlled by the computing device so that the first external sample and the diluent flow at relative flow rates suitable for achieving a target dilution in the diluted sample. Determining the target dilution may include: determining that the analyte concentration in the external sample measured in method (a) is greater than a predetermined maximum concentration (e.g., an upper limit of a calibration range); and calculating or estimating the target dilution of the external sample so that the analyte concentration of the diluted sample is less than the predetermined maximum concentration. Analytical methods

[0123] The present invention also relates to a method of analysis using a spectrometer as disclosed herein. Fig.11 As schematically shown in FIG. 1 , the analysis method 1100 includes: providing one or more external samples for analysis at a sample source step 1110; and analyzing at least the first sample of the one or more external samples by a first analysis method system without diluting the first sample 1130. In some embodiments, the analysis method 1100 further includes step 1150: analyzing at least the first sample or the second sample of the one or more external samples by a second analysis method system while performing online dilution on the first sample or the second sample.

[0124] The first analysis method system of step 1130 includes: (i) flowing a first sample along a continuous flow path from a sample source to an analytical sample reservoir, sub-step 1132; and (ii) Sub-step 1134 of subsequently delivering the first sample from the analytical sample reservoir to an analytical device for spectroscopic analysis.

[0125] The second analysis method system of step 1150 includes: (i) allowing the first sample or the second sample to flow from the sample source to the external sample reservoir, sub-step 1152; (ii) after sub-step 1152, sub-step 1154 of flowing the first sample or the second sample from the external sample reservoir to the sample dilution junction; (iii) simultaneously with sub-step 1154, flowing a diluent to the sample dilution junction thereby diluting the first sample or the second sample to produce a diluted sample, sub-step 1156; (iv) flowing the diluted sample from the sample dilution junction to the analytical sample reservoir, sub-step 1158; and (v) Following sub-step 1158, sub-step 1160 of delivering the diluted sample from the analytical sample reservoir to an analytical device for spectral analysis.

[0126] In some embodiments, method 1100 includes determining a target dilution of the first sample based on the spectral analysis of the first sample in substep 1134, and analyzing the first sample (i.e., the same external sample) by a second analysis methodology in step 1150. A first fluid pump and a second fluid pump of the sample delivery system are controlled in substeps 1154 and 1156 to flow the first sample and the diluent at relative flow rates suitable for achieving the target dilution in the diluted sample.

[0127] Determining the target dilution may include: determining that the analyte concentration in the first sample is greater than a predetermined maximum concentration (e.g., the upper limit of the calibration range); and calculating or estimating the target dilution for the first sample so that the analyte concentration of the diluted sample produced in substep 1156 is below the predetermined maximum concentration. Thus, methods according to such embodiments may be useful for online dilution of samples in which one or more analytes are found to be out of range in initial analysis.

[0128] In some embodiments, method 1100 includes: providing a plurality of external samples for analysis at a sample source in step 1110; analyzing the plurality of external samples by a first analysis methodology in step 1130; identifying any out-of-range samples in the plurality of external samples having an analyte concentration greater than a predetermined maximum concentration (e.g., an upper limit of a calibration range) based on the spectral analysis of the plurality of external samples obtained in sub-step 1134; and analyzing the out-of-range sample (if identified) by a second analysis methodology in step 1150. Controlling the first fluid pump and the second fluid pump in sub-steps 1154 and 1156 of the second analysis methodology causes the out-of-range sample and the diluent to flow at relative flow rates suitable for providing an analyte concentration of the diluted sample below the predetermined maximum concentration.

[0129] The method according to such an embodiment is useful for spectroscopically analyzing a series of external samples and then reanalyzing only those samples found to be out of range using appropriate online dilution to bring the analyte concentration down to within the analytical range. Since the sample bypasses the dilution system of the sample delivery system during the initial analysis, the method system provides excellent instrument productivity.

[0130] In some embodiments, the methods disclosed herein can be used to generate calibration data for a calibration curve. Thus, method 1100 includes: in step 1100, providing a calibration sample for analysis at a sample source, the calibration sample having one or more analytes of known concentration; in step 1130, analyzing the calibration sample by a first analysis method system, thereby delivering the calibration sample to an analysis device for spectral analysis; and in step 1150, analyzing the calibration sample one or more times by a second analysis method system, thereby delivering one or more diluted calibration samples having one or more analytes of known concentration to an analysis device for spectral analysis.

[0131] Now we will refer to Figures 1 to 5 To describe an analysis method according to an embodiment of method 1100 , these figures depict an ICP-OES or ICP-MS spectrometer including a sample delivery system 100 and an analysis device 124 .

[0132] The method includes providing one or more external samples for analysis at a sample source 134 (step 1110). Suitably, the sampler 134 is an autosampler, and the plurality of external samples (e.g., in vials) are provided in the autosampler for analysis. The method includes analyzing at least a first sample of the samples provided at the sample source 134 by a first analysis methodology without diluting the first sample (step 1130). As desired, the method may further include analyzing at least the first sample or the second sample of the one or more external samples by a second analysis methodology with an online dilution of the first sample or the second sample (step 1150).

[0133] In step 1130, the first analytical method requires that the second multi-port valve 106 and the third multi-port valve 108 be maintained in their first valve positions, such as Figure 1 and Figure 2 The first multi-port valve 104 is also initially in its first valve position, as shown in FIG. Figure 1102 is configured to provide a continuous flow path from the sample source 134 to the analytical sample loop 110. A fourth fluid pump 142 located downstream of the analytical sample loop 110 is activated to flow the first sample along the continuous flow path from the sample source 134 to the analytical sample loop 110 and all the way to the exhaust port 140 (sub-step 1132). The flow rate can be high (e.g., about 30 ml / min) to allow rapid loading of the first sample, and the flow continues for a time sufficient to flush the line and ensure that a representative aliquot of the first sample is obtained in the analytical sample loop 110. At the same time, the third fluid pump 114 and the fifth fluid pump 128 cause a constant flow rate of the first carrier fluid 116 (e.g., 0.3 ml / min for ICP-MS and 1 ml / min for ICP-OES) and the internal standard 130 to flow through the first multi-port valve 104 to the nebulizer 122.

[0134] Once a representative analytical sample of the first sample has been loaded into analytical sample loop 110, the analytical sample is delivered to nebulizer 122 via sample delivery line 120 by switching first multi-port valve 104 to its second valve position, as shown in FIG. Figure 2 Thus, the flow of the first carrier fluid 116 is diverted through the analytical sample loop 110, pushing the analytical sample out of the valve 104 (where it is mixed with the flow of the internal standard) and via the sample delivery line 120 to the nebulizer 122, where it is atomized and subsequently analyzed in the analytical device 124 for spectral analysis (sub-step 1134). Optionally, when the first multi-port valve 104 is switched to its second valve position, the bubble injector 126 injects bubbles to physically separate the first carrier fluid 116 from the first sample.

[0135] After the first sample has been delivered for analysis, the first multi-port valve 104 switches back to its first valve position so that the flow of the first carrier fluid 116 is again directed to the nebulizer through the valve 104. Optionally, the continuous flow path from the sample source 134 to the analytical sample loop 110 and onward to the exhaust port 140 is then flushed with a cleaning fluid between analyses. For example, the cleaning fluid can be provided from a cleaning fluid source in the autosampler.

[0136] With both valves 106 and 108 maintained in their first valve positions, as Figure 1 and Figure 2 As depicted, any number of samples provided at the sample source 134 may be sequentially analyzed by the first analysis methodology, as described herein. Due to the continuous flow path from the sample source 134 to the analysis sample loop 110, one or more external samples advantageously flow directly to the analysis sample loop 110 without passing through the external sample loop 144, thereby minimizing the total time required for each analysis.

[0137] In step 1150, a sample (the first sample or the second sample) of the one or more external samples may be analyzed by a second analysis method. Initiating the second analysis method requires that the second multi-port valve 106 and the third multi-port valve 108 are switched to their second valve positions, wherein the first multi-port valve 104 is in its first valve position, such as Figure 3 As depicted. The valve assembly 102 is thus configured to allow flow of the external sample from the sample source 134 to the external sample reservoir 144. The fourth fluid pump 142 is activated to allow the first sample or the second sample to flow from the sample source 134 to the external sample reservoir 144 and all the way to the discharge port 140 (sub-step 1152). The flow rate can be high (e.g., about 30 ml / min) to allow rapid sample addition, and the flow continues for a time sufficient to flush the line and ensure that a representative aliquot of the first sample or the second sample is obtained in the external sample reservoir 144.

[0138] The second method system may also include the sub-step of preparing the delivery system for the second carrier fluid 152 and the diluent 158. Thus, the bypass valve 138 may be switched to its second configuration (also as Figure 3 ), and the first fluid pump 150 and the second fluid pump 156 may be activated to flush the analytical sample loop 110 and other lines in the flow path to the exhaust port 140 with the second carrier fluid 152 and the diluent 158. Optionally, spacer gas bubbles may be introduced into the carrier fluid line 154 and the dilution fluid line 160 by temporarily switching the second multi-port valve 106 to its first valve position and reversing the flow direction of the first fluid pump 150 and the second fluid pump 156, as previously described herein.

[0139] Once the external sample reservoir 144 contains a representative sample of the first sample or the second sample, and the delivery system for the second carrier fluid 152 and the diluent 158 ​​is appropriately prepared, the third multi-port valve 108 is switched back to its first valve position, such as Figure 4 The first fluid pump 150 is activated to flow the second carrier fluid 152 through the external sample reservoir 144, pushing the first sample or the second sample out of the valve 108 via the sample dilution junction 164 (sub-step 1154). The second fluid pump 156 is activated to flow the diluent 158 ​​through and out of the valve 108 via the sample dilution junction 164, thereby contacting and mixing the first sample or the second sample with the diluent 158 ​​to produce a diluted sample (sub-step 1156). The dilution level of the diluted sample is controlled by the relative flow rates of the second carrier fluid 152 and the diluent 158.

[0140] Continue to refer to Figure 4, the diluted sample flows from the sample dilution junction 164 via the valve 106 (in its second valve position) to the analytical sample loop 110 and on to the exhaust port 140, wherein the flow continues at least until the analytical sample loop 110 contains a representative aliquot of the diluted sample (sub-step 1158). The diluted analytical sample thus loaded into the analytical sample loop 110 is then delivered to the nebulizer 122 by switching the first multi-port valve 104 to its second valve position (sub-step 1160), as shown. Figure 5 Depicted and in a manner similar to that described herein for the first analytical methodology.

[0141] Valve 108 can be switched to its second valve position simultaneously with valve 104, such as Figure 5 As depicted, the flow path from the sample source 134 through the external sample reservoir 144 and all the way to the discharge port 140 can be flushed with a cleaning fluid between analyses. For example, the cleaning fluid can be provided from a cleaning fluid source in the autosampler. The flow of the second carrier fluid 152 and / or the diluent 158 ​​can also continue, thereby flushing the diluted sample out of the flow path from the sample dilution junction 164 to the discharge port 140. If necessary, the pumps 150 and 156 can then be refilled with the second carrier fluid 152 and the diluent 158 ​​from the diluent source 162.

[0142] The external sample reservoir 144 may then be reloaded with another external sample of the plurality of external samples provided at the sample source 134, thereby facilitating a rapid turnaround between successive in-line dilution analyses.

[0143] As will be clear to the skilled person, it is possible to use methods including Figures 6 to 10 The depicted sample delivery system 200 or sample delivery system 300 and the ICP-OES or ICP-MS spectrometer of the analysis device 224 perform a similar analysis method (according to another embodiment of the method 1100).

[0144] The analysis methods previously described herein generally involve analysis of one or more samples, wherein at least one sample is spectrally analyzed without online dilution. As previously explained, such methods advantageously allow for rapid analysis of undiluted samples because an external sample reservoir is bypassed when transferring the sample from a sample source to an analysis sample reservoir. However, the sample delivery system disclosed herein is also suitable for analyzing a sample or a series of samples in which each sample is diluted online to a specified dilution level (i.e., a dilution level not determined based on an initial undiluted analysis).

[0145] Therefore, the present disclosure also provides a method for analysis using a spectrometer as disclosed herein, the method comprising: providing one or more external samples at a sample source for analysis; and analyzing at least a first sample of the one or more external samples by an analysis method system without diluting the first sample, the analysis method system comprising (i) allowing the first sample to flow from the sample source to an external sample reservoir, (ii) subsequently allowing the first sample to flow from the external sample reservoir to a sample dilution junction, (iii) simultaneously allowing a diluent to flow to the sample dilution junction to thereby dilute the first sample to produce a diluted sample, (iv) allowing the diluted sample to flow from the sample dilution junction to an analysis sample reservoir, and (v) subsequently delivering the diluted sample from the analysis sample reservoir to an analysis device for spectral analysis.

[0146] Those skilled in the art will appreciate that the invention described herein is susceptible to changes and modifications other than those specifically described. It should be understood that the present invention includes all such changes and modifications within the spirit and scope of the present invention.

Claims

1. A sample delivery system for an analytical instrument, comprising: a valve assembly comprising one or more valves, the valve assembly being configured to receive an external sample from a sample source; an external sample reservoir coupled to a sample dilution junction via the valve assembly, wherein the valve assembly is configurable to alternatively allow (i) flow of the external sample from the sample source to the external sample reservoir, or (ii) flow of the external sample from the external sample reservoir to the sample dilution junction; a first fluid pump for controlling the flow of the external sample from the external sample reservoir to the sample dilution junction; a second fluid pump for controlling the flow of a diluent to the sample dilution junction, thereby diluting the external sample to produce a diluted sample; and An analytical sample reservoir configured to deliver the analytical sample contained therein to an analytical device of the analytical instrument, wherein the analytical sample reservoir is connected to the sample dilution junction via the valve assembly, and wherein the valve assembly can be configured to alternatively allow (i) the external sample to flow along a continuous flow path from the sample source to the analytical sample reservoir, thereby bypassing the external sample reservoir, or (ii) the diluted sample to flow from the sample dilution junction to the analytical sample reservoir.

2. The sample delivery system according to claim 1, wherein: The analysis sample reservoir is configured as an analysis sample loop, which is coupled to two ports of a first multi-port valve of the valve assembly, wherein an analysis sample can be loaded into the analysis sample loop when the first multi-port valve is in a first valve position, and wherein the analysis sample can be delivered from the analysis sample loop to the analysis device when the first multi-port valve is switched to a second valve position.

3. The sample delivery system of claim 2, further comprising a third fluid pump for flowing a first carrier fluid to the first multi-port valve, wherein: The first multi-port valve may be configured to allow the first carrier fluid to flow directly through the first multi-port valve to the analysis device when the first multi-port valve is in the first valve position, and to divert the first carrier fluid to pass through the analysis sample loop when the first multi-port valve is switched to the second valve position, thereby delivering the analysis sample from the analysis sample loop to the analysis device.

4. The sample delivery system of claim 3, further comprising a bubble injector configured to inject gas bubbles to separate the first carrier fluid from the analytical sample when the first carrier fluid flows through the analytical sample loop.

5. The sample delivery system according to any one of claims 1 to 4, further comprising a fourth fluid pump or vacuum source, which is used to make the external sample flow along the continuous flow path from the sample source to the analytical sample reservoir.

6. The sample delivery system of claim 5, adapted to bypass the fourth fluid pump or vacuum source when the diluted sample flows from the sample dilution junction to the analytical sample reservoir.

7. A sample delivery system according to claim 5 or claim 6, wherein: The valve assembly may be configured to allow the fourth fluid pump or vacuum source to cause the external sample to flow from the sample source to the external sample reservoir.

8. The sample delivery system according to any one of claims 1 to 6, wherein: The valve assembly may be configured to allow the first fluid pump to flow the external sample from the sample source to the external sample reservoir.

9. The sample delivery system according to any one of claims 1 to 8, wherein: The valve assembly includes a second multi-port valve connected to the analytical sample reservoir, wherein the second multi-port valve is switchable between at least a first valve position and a second valve position, the first valve position allowing the external sample to flow along the continuous flow path from the sample source to the analytical sample reservoir, and the second valve position allowing the diluted sample to flow from the sample dilution junction to the analytical sample reservoir.

10. The sample delivery system according to claim 9, wherein: The second multi-port valve is switchable to a third valve position to allow flow of the external sample from the sample source to the external sample reservoir.

11. The sample delivery system of claim 10, wherein: The second fluid pump controls the flow of diluent through the second multi-port valve to the sample dilution junction when the second multi-port valve is switched to the second valve position.

12. The sample delivery system according to any one of claims 1 to 11, wherein: The external sample reservoir is configured to be coupled to an external sample loop of a valve of the valve assembly.

13. The sample delivery system according to any one of claims 1 to 12, wherein: The external sample reservoir is configured as an external sample loop coupled to two ports of a third multi-port valve of the valve assembly, wherein the external sample can be loaded into the external sample loop when the third multi-port valve is in a second valve position, and wherein the external sample can be delivered from the external sample loop to the sample dilution junction when the third multi-port valve is switched to a first valve position.

14. The sample delivery system of claim 13, wherein: The valve assembly may be configured to allow the first fluid pump to flow a second carrier fluid through the outer sample loop when the third multi-port valve is switched to the first valve position, thereby causing the external sample to flow from the outer sample loop to the sample dilution junction.

15. The sample delivery system of claim 14, the sample delivery system being configurable to introduce gas bubbles to space the second carrier fluid from the external sample as the second carrier fluid flows through the external sample loop.

16. The sample delivery system according to any one of claims 13 to 15, wherein: The valve assembly may be configured to allow the second fluid pump to flow the diluent through the third multi-port valve to the sample dilution junction when the third multi-port valve is in the first valve position.

17. The sample delivery system according to any one of claims 13 to 16, wherein: The valve assembly may be configured to allow flow of the external sample along the continuous flow path from the sample source via the third multi-port valve to the analytical sample reservoir when the third multi-port valve is in the first valve position.

18. The sample delivery system according to any one of claims 1 to 17, wherein: The first fluid pump and the second fluid pump are configured to flow the external sample and the diluent at a relative flow rate (v / v) ranging from 10:1 to 1:1000.

19. The sample delivery system according to any one of claims 1 to 18, wherein: The first fluid pump and the second fluid pump are configured to flow the external sample and the diluent at a combined flow rate between 2 ml / min and 20 ml / min.

20. The sample delivery system according to any one of claims 1 to 19, wherein: The volume of the external sample reservoir is no more than 20% greater than the volume of the analytical sample reservoir.

21. The sample delivery system according to any one of claims 1 to 20, further comprising the sample source, wherein The sample source is coupled to the external sample reservoir and to the analytical sample reservoir via the valve assembly.

22. The sample delivery system of claim 21, wherein: The sample source is selected from an autosampler and an automated interface adapted to sample a process fluid.

23. A spectrometer comprising an analytical device and a sample delivery system according to any one of claims 1 to 22.

24. The spectrometer according to claim 23, wherein: The analytical device comprises a plasma source.

25. A spectrometer according to claim 23 or claim 24, which is an ICP-OES and / or ICP-MS spectrometer.

26. The spectrometer according to any one of claims 23 to 25, further comprising a computing device for controlling the sample delivery system to deliver an external sample for spectral analysis by method (a) or method (b), wherein: The method (a) comprises (i) flowing the external sample from the sample source to the analytical sample reservoir along the continuous flow path without diluting the external sample, and (ii) subsequently delivering the external sample from the analytical sample reservoir to the analytical device for spectroscopic analysis, and Method (b) includes (i) causing the external sample to flow from the sample source to the external sample reservoir, (ii) subsequently causing the external sample to flow from the external sample reservoir to the sample dilution junction, (iii) simultaneously causing a diluent to flow to the sample dilution junction thereby diluting the external sample to produce a diluted sample, (iv) causing the diluted sample to flow from the sample dilution junction to the analysis sample reservoir, and (v) subsequently delivering the diluted sample from the analysis sample reservoir to the analysis device for spectral analysis.

27. The spectrometer according to claim 26, wherein The computing device is adapted to: delivering a first external sample for spectroscopic analysis by method (a); determining a target dilution of the first external sample based on a spectral analysis of the first external sample; and Delivering a diluted sample comprising the first external sample and the diluent for spectral analysis by method (b), wherein the first fluid pump and the second fluid pump are controlled to cause the first external sample and the diluent to flow at relative flow rates suitable for achieving the target dilution in the diluted sample.

28. A method for analysis using a spectrometer according to any one of claims 23 to 27, comprising: providing one or more external samples at a sample source for analysis; as well as At least a first sample of the one or more external samples is analyzed by a first analytical method system without diluting the first sample, the first analytical method system comprising (i) allowing the first sample to flow from the sample source to the analytical sample reservoir along the continuous flow path, and (ii) subsequently delivering the first sample from the analytical sample reservoir to the analytical device for spectral analysis.

29. The method of claim 28, further comprising analyzing at least the first sample or the second sample among the one or more external samples by a second analysis method system while performing online dilution on the first sample or the second sample, the second analysis method system comprising (i) flowing the first sample or the second sample from the sample source to the external sample reservoir, (ii) subsequently flowing the first sample or the second sample from the external sample reservoir to the sample dilution junction, (iii) simultaneously flowing a diluent to the sample dilution junction to thereby dilute the first sample or the second sample to produce a diluted sample, (iv) flowing the diluted sample from the sample dilution junction to the analysis sample reservoir, and (v) subsequently delivering the diluted sample from the analysis sample reservoir to the analysis device for spectral analysis.

30. The method of claim 29, comprising: determining a target dilution of the first sample based on a spectral analysis of the first sample obtained by the first analytical methodology; as well as The first sample is analyzed by the second analytical methodology, wherein the first and second fluid pumps of the sample delivery system are controlled to flow the first sample and the diluent at relative flow rates suitable for achieving the target dilution in the diluted sample.

31. The method of claim 29, comprising: providing a calibration sample for analysis at the sample source, the calibration sample having a known concentration of one or more analytes; analyzing the calibration sample by the first analytical methodology, thereby delivering the calibration sample to the analytical device for spectral analysis; as well as The calibration samples are analyzed one or more times by the second analytical methodology, whereby one or more diluted calibration samples having known concentrations of one or more analytes are delivered to the analytical device for spectroscopic analysis.

32. The method of claim 28, comprising: providing a plurality of external samples at the sample source for analysis; Analyzing the plurality of external samples by the first analytical method system; identifying any out-of-range sample from the plurality of external samples having an analyte concentration greater than a predetermined maximum concentration based on the spectral analysis of the plurality of external samples; as well as If identified, the out-of-range sample is analyzed by a second analysis method system while performing online dilution on the out-of-range sample, the second analysis method system comprising (i) flowing the out-of-range sample from the sample source to the external sample reservoir, (ii) subsequently flowing the out-of-range sample from the external sample reservoir to the sample dilution junction, (iii) simultaneously flowing a diluent to the sample dilution junction to thereby dilute the out-of-range sample to produce a diluted sample having an analyte concentration less than the predetermined maximum concentration, (iv) flowing the diluted sample from the sample dilution junction to the analysis sample reservoir, and (v) subsequently delivering the diluted sample from the analysis sample reservoir to the analysis device for spectral analysis.

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