Inductive device for inductively coupled plasma torches and methods and systems including same

Abstract

An induction device includes a helical structure including a first aperture and a non-helical structure including a second aperture. The first aperture and the second aperture define a passage configured to receive a portion of a body of an inductively coupled plasma (ICP) torch.

Description

Technical Field

[0001] The present technology relates to plasma sources, and more particularly, to inductively coupled plasma torches and induction devices used therewith. Background Art

[0002] Some inductively coupled plasma (ICP) devices use an ICP torch including an induction device to generate plasma. It is desirable to design the induction device such that a robust plasma is generated that can ionize challenging samples without extinguishing. Summary of the Invention

[0003] Some embodiments of the present technology are directed to an induction device including a spiral structure and a non-spiral structure, the spiral structure including a first orifice, the non-spiral structure including a second orifice. The first orifice and the second orifice define a passageway configured to receive a portion of the body of an inductively coupled plasma (ICP) torch, and the passageway defines a longitudinal axis.

[0004] In some embodiments, the spiral structure includes a spiral plate and the non-spiral structure includes a flat plate.

[0005] In some embodiments, the spiral plate includes a body including the first orifice and first and second legs extending away from the body. In some embodiments, the flat plate includes a body including the second orifice and first and second legs extending away from the body.

[0006] In some embodiments, the first leg of the spiral plate is axially spaced from the flat plate by a first distance, and the second leg of the spiral plate is axially spaced from the flat plate by a second distance. The second distance may be greater than the first distance. The first distance may be the minimum gap between the spiral plate and the flat plate, and the second distance may be the maximum gap between the spiral plate and the flat plate. The first distance may be 2 to 3 mm and / or the second distance may be 5 to 6 mm.

[0007] In some embodiments, the first leg of the spiral plate is axially aligned with the second leg of the flat plate, and the second leg of the spiral plate is laterally offset from the flat plate relative to the longitudinal axis.

[0008] In some embodiments, the second leg of the spiral plate and the first leg of the flat plate are each configured to be supplied with radio frequency current, and the first leg of the spiral plate and the second leg of the flat plate are configured to be connected to ground.

[0009] In some embodiments, the induction device further includes a spacer between the first leg of the spiral plate and the second leg of the flat plate. The spacer may contact each of the first leg of the spiral plate and the second leg of the flat plate.

[0010] In some embodiments, the sensing device further includes an electrode that is connected to each of the second leg of the spiral plate, the first leg of the flat plate, and the second leg of the flat plate.

[0011] In some embodiments, the sensing device further includes a conductive plate to which the spiral plate and the flat plate are coupled. The electrode and / or the conductive plate can be configured as a heat sink to facilitate cooling of the spiral plate and the flat plate.

[0012] In some embodiments, the body of the spiral plate is in the shape of a ring and makes substantially a single rotation or turn between the first leg and the second leg of the spiral plate.

[0013] In some embodiments, the spiral plate and the flat plate each have a thickness of about 2 mm.

[0014] In some embodiments, the spiral plate has a pitch of 4 to 6 mm per revolution.

[0015] In some embodiments, the spiral structure includes a coil. The coil can be a single coil.

[0016] In some embodiments, the spiral structure and / or the non-spiral structure is formed of aluminum.

[0017] In some embodiments, the spiral structure and / or the non-spiral structure is formed of copper.

[0018] Some other embodiments of the present technology are directed to an inductively coupled plasma (ICP) torch that includes: a syringe configured to receive a flow of sample fluid; a plurality of tubes disposed around the syringe and configured to receive and direct a flow of one or more torch gases; and a sensing device disposed around at least one of the plurality of tubes, the sensing device configured to receive a radio frequency current to inductively excite at least one of the one or more torch gases to generate a plasma near a distal end of the ICP torch. The sensing device includes a spiral structure and a non-spiral structure, the spiral structure includes a first orifice, and the non-spiral structure includes a second orifice. The first orifice and the second orifice define a passage configured to receive the at least one of the plurality of tubes, and the passage defines a longitudinal axis.

[0019] In some embodiments, the spiral structure includes a spiral plate, and the non-spiral structure includes a flat plate.

[0020] In some embodiments, the spiral plate includes a body that includes the first orifice and a first leg and a second leg that extend away from the body, and the flat plate includes a body that includes the second orifice and a first leg and a second leg that extend away from the body.

[0021] In some embodiments, a first leg of the helical plate is axially spaced from the flat plate by a first distance, a second leg of the helical plate is axially spaced from the flat plate by a second distance, and the second distance is greater than the first distance. The first distance may be the minimum clearance between the helical plate and the flat plate, and the second distance may be the maximum clearance between the helical plate and the flat plate. The first distance may be 2 to 3 mm and / or the second distance may be 5 to 6 mm.

[0022] In some embodiments, the first leg of the helical plate is axially aligned with the second leg of the flat plate, and the second leg of the helical plate is laterally offset from the flat plate relative to the longitudinal axis.

[0023] In some embodiments, the second leg of the helical plate and the first leg of the flat plate are each configured to be supplied with radio frequency current, and the first leg of the helical plate and the second leg of the flat plate are configured to be connected to ground.

[0024] In some embodiments, the ICP torch further includes a spacer between the first leg of the helical plate and the second leg of the flat plate. The spacer may contact each of the first leg of the helical plate and the second leg of the flat plate.

[0025] In some embodiments, the ICP torch further includes an electrode that is connected to each of the second leg of the helical plate, the first leg of the flat plate, and the second leg of the flat plate.

[0026] In some embodiments, the ICP torch further includes a conductive plate to which the helical plate and the flat plate are coupled. The electrode and / or the conductive plate may be configured as a heat sink to facilitate cooling of the helical plate and the flat plate.

[0027] In some embodiments, the body of the helical plate is in the shape of a ring and makes substantially a single rotation or turn between the first leg and the second leg of the helical plate.

[0028] In some embodiments, the helical plate and the flat plate each have a thickness of about 2 mm.

[0029] In some embodiments, the helical plate has a pitch of 4 to 6 mm per revolution.

[0030] In some embodiments, the helical structure includes a coil. The coil may be a single coil.

[0031] In some embodiments, the helical structure and / or the non-helical structure is formed of aluminum.

[0032] In some embodiments, the helical structure and / or the non-helical structure is formed of copper.

[0033] In some embodiments, the plurality of tubes includes: an intermediate tube that surrounds a syringe, wherein the syringe and the intermediate tube define an auxiliary gas channel configured to receive a flow of auxiliary gas; and a plasma tube that surrounds the intermediate tube, wherein the intermediate tube and the plasma tube define a plasma gas channel configured to receive a flow of plasma gas.

[0034] In some embodiments, the maximum axial gap between the distal end of the intermediate tube and the helical plate is 4.9 to 5.1 mm.

[0035] In some embodiments, the axial gap between the distal end of the syringe and the distal end of the intermediate tube is 2 to 3 mm.

[0036] Some other embodiments of the present technology are directed to an optical emission spectroscopy (ICP-OES) system including an ICP torch as described herein.

[0037] Some other embodiments of the present technology are directed to a method for generating a plasma. The method includes providing an inductively coupled plasma (ICP) torch that includes: a syringe tube including a syringe flow channel for receiving a flow of a sample fluid; an intermediate tube that surrounds the syringe tube, wherein the syringe and the intermediate tube define an auxiliary gas channel configured to receive a flow of auxiliary gas; a plasma tube that surrounds the intermediate tube, wherein the intermediate tube and the plasma tube define a plasma gas channel configured to receive a flow of plasma gas; and an induction device that includes a helical structure and a non-helical structure, the helical structure including a first orifice, the non-helical structure including a second orifice, wherein the first orifice and the second orifice define a passage configured to receive the plasma tube. The method includes: flowing auxiliary gas through the auxiliary gas channel; flowing plasma gas through the plasma gas channel; and supplying a radio frequency current to the induction device to inductively excite the auxiliary gas to generate a plasma near the distal end of the torch.

[0038] By reading the accompanying drawings and the detailed description of the following embodiments, those of ordinary skill in the art will recognize additional features, advantages, and details of the present technology, and such description is merely illustrative of the present technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which form a part of the specification, illustrate embodiments of the present technology.

[0040] Figure 1 is a schematic diagram of an ICP torch system according to some embodiments.

[0041] Figure 2 is according to some embodiments Figure 1 of the induction device of the ICP torch system in perspective view.

[0042] Figure 3 is Figure 1 Another perspective view of the induction device of the ICP torch system of

[0043] Figure 4 is Figure 1 A partial top view of the induction device of the ICP torch system of

[0044] Figure 5 is Figures 2 to 4 The front view of the spiral plate of the induction device of

[0045] Figure 6 is Figure 5 The side view of the spiral plate of

[0046] Figure 7 is Figures 2 to 4 The front view of the flat plate of the induction device of

[0047] Figure 8 is Figure 5 and Figure 6 of the spiral plate and Figure 7 The side view of the flat plate of

[0048] Figure 9 is according to some other embodiments of Figure 1 The side view of the induction device of the ICP torch system of

[0049] Figure 10 is a diagram of an optical emission spectroscopy system including an ICP torch system according to some embodiments. DETAILED DESCRIPTION

[0050] Many inductively coupled plasma - optical emission spectroscopy (OES) systems cannot handle "difficult - to - operate" samples. These systems do not generate a plasma that is "robust" enough to handle difficult matrices without extinguishing. One measure of robustness is the minimum amount by which the power can be reduced while still maintaining the plasma. Another way to test robustness is to determine how much methanol can be passed through the system while maintaining the plasma.

[0051] Some embodiments of the present technology are directed to an induction device for an ICP torch. The induction device can include a spiral structure (e.g., a spiral plate) and a flat structure (e.g., a flat plate), which are electrically connected to form an induction field that produces a more robust plasma.

[0052] Some known induction devices use coils. A common problem with a coil - like arrangement is that the temperature of the resulting plasma follows the coil. The present inventors have determined that plates result in a more uniform plasma, which is desirable.

[0053] The present inventors have determined that various parameters, such as the spacing between the plates as described herein and the spacing between the plates and components of the ICP torch, are important for generating a robust plasma.

[0054] Figure 1 FIG. 4 is a schematic diagram of an ICP torch system 10 according to some embodiments. The ICP torch system 10 includes a torch 100, a sample source 24, an auxiliary gas source 26, and a plasma gas source 28. In use, a sample stream or gas stream SG (from the sample source 24), an auxiliary gas stream or gas stream AG (from the auxiliary gas source 26), and a plasma gas stream or gas stream PG (from the plasma gas source 28) are each forced through or flow toward the distal end 106D of the torch 100. The ICP torch system 10 generates a plasma P at the distal end 106D by means of the auxiliary gas AG.

[0055] The plasma P can be used as an ionization source. In some embodiments, the plasma P decomposes the sample from the sample gas stream SG into its constituent elements and converts those elements into ions. The sample can be an analyte of interest.

[0056] The sample source 24 can include a supply of the sample to be analyzed. The sample of interest can be provided in a solution or mixture. The sample source 24 can include a syringe, a nebulizer, or other suitable device configured to deliver a solid, liquid, or gas sample to the torch 100.

[0057] The auxiliary gas source 26 can include a supply of the auxiliary gas AG. The auxiliary gas AG can be any suitable gas through which the plasma P can be formed or generated as described herein. In some embodiments, the auxiliary gas AG is argon. In other embodiments, the auxiliary gas AG is nitrogen. The auxiliary gas source 26 is configured to provide a pressurized supply and flow of the auxiliary gas AG to the torch 100. The auxiliary gas source 26 can include a flow generator (e.g., a pump) and / or can include a positive pressure supply of the auxiliary gas AG.

[0058] The plasma gas source 28 can include a supply of the plasma gas PG. The plasma gas PG can be any suitable gas for providing the functions as described herein. In some embodiments, the plasma gas PG and the auxiliary gas AG have the same gas composition. In some embodiments, the plasma gas PG is argon. In other embodiments, the plasma gas PG is nitrogen. The plasma gas source 28 is configured to provide a pressurized supply and flow of the plasma gas PG to the torch 100. The plasma gas source 28 can include a flow generator (e.g., a pump) and / or can include a positive pressure supply of the plasma gas PG.

[0059] The torch 100 has a torch longitudinal axis A-A.

[0060] The ICP torch system 10 or torch 100 includes an induction device or induction device assembly 200. In some embodiments, as described in more detail below, the induction device 200 may include helical elements or structures and non-helical elements or structures.

[0061] The torch 100 includes a syringe 120, an intermediate tube 130, and a plasma tube 140. The intermediate tube 130 circumferentially surrounds the syringe 120, and the plasma tube 140 circumferentially surrounds the intermediate tube 130. In some embodiments, the syringe 120, the intermediate tube 130, and the plasma tube 140 are substantially concentric about the torch axis A-A.

[0062] The syringe 120 may be formed of a suitable material. In some embodiments, the syringe tube 120 is formed of quartz, sapphire, or platinum.

[0063] The auxiliary tube 130 may be formed of a suitable material. In some embodiments, the auxiliary tube 130 is formed of quartz.

[0064] The plasma tube 140 may be formed of a suitable material. In some embodiments, the plasma tube 140 is formed of quartz.

[0065] The syringe 120 has an inlet 122 and an outlet 124. The syringe 120 includes a distal or end portion 120D. The intermediate tube 130 has an inlet 132 and an outlet 134. The intermediate tube 130 includes a distal or end portion 130D. The plasma tube 140 has an inlet 142 and an outlet 144. The plasma tube 140 has a distal or end portion corresponding to the distal end 106D of the torch 100.

[0066] The syringe 120 defines an axially extending syringe flow channel or sample channel 126 that fluidly connects the inlet 122 and the outlet 124. The syringe 120 and the intermediate tube 130 define an axially extending auxiliary gas channel 136 between the opposing surfaces of the syringe 120 and the intermediate tube 130. The auxiliary gas channel 136 fluidly connects the inlet 132 and the outlet 134. The intermediate tube 130 and the plasma tube 140 define an axially extending gas channel 146 between the opposing surfaces of the intermediate tube 130 and the plasma tube 140. The plasma gas channel 146 fluidly connects the inlet 142 and the outlet 144.

[0067] A sample source 24, an auxiliary gas source 26, and a plasma gas source 28 may be fluidly coupled to the inlet 122, the inlet 132, and the inlet 142, respectively, through corresponding conduits 29.

[0068] The induction device 200 may be electrically connected to a radio frequency (RF) power supply 202. The RF power supply may be configured to provide RF energy or current into and through the induction device 200. The induction device will be described in more detail below.

[0069] In use, a sample gas SG flows through a sample gas passage 126, an auxiliary gas AG flows through an auxiliary gas passage 136, and a plasma gas PG flows through a plasma gas passage 146 toward the distal end 106D of the torch 100. It will be appreciated that the auxiliary gas stream AG is isolated from the sample gas stream SG by the syringe tube 120 until the syringe tube outlet 124, and is isolated from the plasma gas stream PG by the intermediate tube 130 until the outlet 134.

[0070] The induction device 200 is powered to inductively heat the auxiliary gas stream AG. An electric spark may be applied for a short time to introduce free electrons into the auxiliary gas stream AG. The auxiliary gas AG is thereby excited into a plasma P. The sample gas stream SG may enter the plasma P, where the sample gas stream evaporates and the molecules of the sample of interest dissociate, and the constituent atoms are ionized.

[0071] In Figure 2 and Figure 3 the induction device 200 is shown in more detail. The induction device 200 may include a helical structure, such as a helical plate 204. The induction device 200 may include a flat structure, such as a flat plate 206. The helical plate 204 includes a first aperture 208, and the flat plate 206 includes a second aperture 210. The first aperture 208 and the second aperture 210 define a passageway 212 that is configured to receive a portion of the body of the ICP torch, such as Figure 1 the plasma tube 140 of the torch 100 as shown in

[0072] Referring Figure 5 , the helical plate 204 may include a body 214 and spaced-apart first and second legs 216 and 218 extending away from the body 214, the body 214 including the first aperture 208. The first leg 216 includes a first fork 220 and a second fork 222, with a gap or slot 224 defined therebetween. Similarly, the second leg 218 includes a first fork 226 and a second fork 228, with a gap or slot 230 defined therebetween. The first leg 216 and the second leg 218 are configured to connect the helical plate 204 to various components such as mounting structures and electrodes.

[0073] Referring Figure 5 and Figure 6 , the body 214 defines a helical loop 232 that makes substantially one complete revolution. As used herein, in various embodiments, the term "substantially one complete revolution" may mean within 50 degrees, within 35 degrees, and within 20 degrees of one complete revolution.

[0074] The helical plate 204 (or helical ring 232) may have a pitch of 3 mm to 7 mm per revolution, and in some embodiments may have a pitch of 4 to 6 mm.

[0075] Reference Figure 7 , the flat plate 206 may include a body 234 and spaced-apart first and second legs 236 and 238 extending away from the body 234, the body 234 including a second orifice 210. The first leg 236 includes a first fork 240 and a second fork 242, with a gap or slot 244 defined therebetween. Similarly, the second leg 238 includes a first fork 246 and a second fork 248, with a gap or slot 250 defined therebetween. The first and second legs 236 and 238 are configured to connect the flat plate 206 to various components such as mounting structures and electrodes.

[0076] The body 234 defines a flat ring 252 that makes substantially one complete revolution.

[0077] Figure 8 The helical plate 204 and the flat plate 206 and the spacing therebetween are illustrated. A first axial spacing or axial gap d1 may exist between the first leg 216 of the helical plate 204 and the flat plate 206. In various embodiments, the spacing d1 may be 0.5 mm to 5 mm, 1 mm to 4 mm, and 2 mm to 3 mm.

[0078] A second axial spacing or axial gap d2 may exist between the second leg 218 of the helical plate 204 and the flat plate 206. In various embodiments, the spacing d2 may be 2 mm to 8 mm, 3 mm to 7 mm, and 5 mm to 6 mm.

[0079] The inventors have determined that optimal performance is obtained when the gap d2 = 2.5 ± 0.5 mm and the gap d3 = 5.5 ± 0.5 mm.

[0080] A third axial spacing or axial gap d3 may exist between the "top" of the helical plate 204 and the "top" of the flat plate 206. In various embodiments, the spacing d3 may be 2 mm to 8 mm, 3 mm to 7 mm, and 5 mm to 6 mm. In some embodiments, the spacing d3 is less than the spacing d2.

[0081] Again referring to Figure 2 and Figure 3 , the first leg 216 of the helical plate 204 may be axially aligned with the second leg 238 of the flat plate 206. The second leg 218 of the helical plate 204 may be laterally offset from the flat plate 206 relative to the longitudinal axis B - B.

[0082] In some embodiments, the second leg 218 of the helical plate 204 and the first leg 236 of the flat plate 206 are each configured to be supplied with radio frequency current. This can be from one or more RF sources, such as Figure 1 the RF power supply 202 shown in

[0083] Reference Figure 4 shows that the spacer 254 can be between the first leg 216 of the helical plate 204 and the second leg 238 of the flat plate 206. In some embodiments, the spacer 254 contacts each of the first leg 216 of the helical plate 204 and the second leg 238 of the flat plate 206. In some embodiments, the spacer has an axial length of 2 to 3 mm.

[0084] As Figure 2 and Figure 3 shown, the electrodes 256, 258, 260 can be connected to each of the second leg 218 of the helical plate 204, the first leg 236 of the flat plate 206, and / or the second leg 238 of the flat plate 206.

[0085] In some embodiments, the helical plate 204 and the flat plate 206 are coupled to a conductive plate 262. The electrodes 256, 258, 260 and the conductive plate 262 can be configured as heat sinks to facilitate cooling of the helical plate 204 and the flat plate 206. The electrodes 256, 258, 260 and the conductive plate 262 can be formed of any suitable material such as aluminum.

[0086] The conductive plate 262 can be coupled to an insulator plate 264. The insulator plate 264 can be coupled to the chassis of a device such as an ICP - OES device.

[0087] Referring again to Figure 1 in various embodiments, the maximum axial gap or axial spacing d4 between the distal end 130D of the intermediate tube 130 and the helical plate 204 can be 0 mm to 10 mm, 2 mm to 8 mm, 4 mm to 6 mm, 4.5 mm to 5.5 mm, and 4.9 mm to 5.1 mm.

[0088] In various embodiments, the maximum axial gap or axial spacing d5 between the distal end 120D of the syringe 120 and the distal end 130D of the intermediate tube 130 can be 0 mm to 5 mm, 1 mm to 4 mm, and 2 mm to 3 mm. In some embodiments, d4 is greater than d5.

[0089] The inventors have determined that optimal performance is obtained when the gap d4 = 5.0 ± 0.1 mm and the gap d5 = 2.5 ± 0.5 mm.

[0090] In various embodiments, the axial gap or axial spacing d6 between the distal end 106D of the torch 100 and the flat plate 206 can be 10 mm to 40 mm, 20 mm to 30 mm, 23 to 25 mm, or about 24 mm. A fixture having a length corresponding to the d6 spacing can be used to properly position the induction device 200 relative to the torch 100.

[0091] In some embodiments, the spiral plate 204 and / or the flat plate 206 have a thickness of 1 mm to 3 mm, and in some embodiments have a thickness of about 2 mm.

[0092] In some embodiments, the spiral plate 204 and the flat plate 206 are formed of aluminum. This can allow for air cooling of the plates (e.g., as opposed to water cooling). In some other embodiments, the spiral plate 204 and / or the flat plate 206 can be formed of copper.

[0093] Reference Figure 9 , in some other embodiments, the spiral structure is a coil, such as a single coil. Thus, the induction device 200 can include a spiral coil 204' and a flat plate 206. The torch 100 can be received through the coil 204' and the flat plate 206. The coil 204' can be formed of any suitable material, such as aluminum or copper.

[0094] In certain configurations, an ICP torch including the induction device described herein can be used for optical emission spectroscopy (OES). Reference Figure 10 , an ICP-OES device or system 500 includes a sample introduction device 520, an ICP torch 100 as described herein and including the induction device 200, and a detection device 526. The system 500 also includes (but not depicted in Figure 10 ) an RF power supply 202, a sample supply 24, an auxiliary gas source 26, and a plasma gas source 28 operably connected to the torch 100.

[0095] The sample introduction device 520 can vary depending on the nature of the sample. In certain examples, the sample introduction device 520 can be an aerosolizer configured to atomize a liquid sample for introduction into the torch 100. In other examples, the sample introduction device 520 can be a syringe configured to receive a sample that can be directly injected or introduced into the torch 100. Given the benefits of the present disclosure, other suitable devices and methods for introducing a sample will be readily selected by those of ordinary skill in the art.

[0096] The detector or detection device 526 can take various forms and can be any suitable device that can detect optical emissions such as optical emission 524. For example, the detection device 526 can include suitable optics such as lenses, mirrors, prisms, windows, band-pass filters, etc. The detection device 526 can also include a grating such as an echelle grating to provide a multi-channel OES device. A grating such as an echelle grating can allow for the simultaneous detection of multiple emission wavelengths. The grating can be positioned within a monochromator or other suitable device for selecting one or more specific wavelengths to monitor. In certain examples, the detection device 526 can include a charge-coupled device (CCD). In other examples, the OES device 500 can be configured to perform a Fourier transform to provide simultaneous detection of multiple emission wavelengths.

[0097] The detection device 526 can be configured to monitor emission wavelengths over a large wavelength range, including but not limited to ultraviolet, visible, near-infrared, far-infrared, etc. The OES device 500 can also include suitable electronics such as a microprocessor and / or computer and suitable circuitry to provide the desired signals and / or for data acquisition. Suitable additional devices and circuitry are known in the art and can be found, for example, on commercially available OES devices such as the AVIO 200 series and AVIO 500 series OES devices available from PerkinElmer Health Sciences, Inc. The optional amplifier 530 (e.g., a photomultiplier tube) can be operated to increase the signal 528 (e.g., amplify the signal from detected photons) and provide the signal to a display 532, which can be a reader, a computer, etc. In examples where the signal 528 is large enough for display or detection, the amplifier 530 can be omitted. In certain examples, the amplifier 530 is a photomultiplier tube (PMT) configured to receive the signal from the detection device 526. However, considering the benefits of the present disclosure, other suitable devices for amplifying the signal will be selected by those of ordinary skill in the art. If desired, the PMT can be integrated into the detector 526.

[0098] In certain other configurations, an ICP torch including the induction device described herein can be used in an ICP - mass spectrometry (MS) device or system or an ICP - atomic absorption spectrometer (AAS) device or system.

[0099] The present technology has been described with reference to the accompanying drawings, in which illustrative embodiments of the technology are shown. In the drawings, the relative dimensions of regions or features may be exaggerated for clarity. However, the present technology can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the present technology to those skilled in the art.

[0100] It will be understood that although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, without departing from the teachings of the present technology, the first element, component, region, layer or section discussed below may be referred to as the second element, component, region, layer or section.

[0101] For convenience, spatial relative terms such as "below", "beneath", "lower", "above", "upper", etc. may be used herein to describe the relationship of one element or feature to another (other) element or feature as illustrated in the figures. It will be understood that, in addition to the orientation depicted in the figures, the spatial relative terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as "below" or "beneath" other elements or features will be oriented "above" the other elements or features. Thus, the term "below" can include both upward and downward orientations. The device may be oriented in other ways (rotated 90° or in other orientations), and the spatial relative descriptors used herein are to be interpreted accordingly.

[0102] As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless expressly stated otherwise. It will also be understood that when used in this specification, the terms "comprises", "comprising" and / or "comprised of", "containing" specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof. It will be understood that when an element is referred to as "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or intervening elements may be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. When the terms "about" or "substantially equal to" are used in the specification, it is intended that the value is plus or minus 5% of the specified value.

[0103] Note that any one or more aspects or features described with respect to one embodiment may be incorporated in different embodiments, even though not specifically described relative thereto. That is, all embodiments and / or features of any embodiment can be combined in any manner and / or combination. The applicant reserves the right to change any originally filed claim or to file any new claim accordingly, including the right to amend any originally filed claim to depend on and / or incorporate any feature of any other claim, even though not originally claimed in that manner. These and other objects and aspects of the present technology will be explained in detail in the specification set forth herein.

[0104] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. It will also be understood that terms (such as those defined in common dictionaries) should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0105] The foregoing is a description of the present technology and should not be construed as a limitation thereof. Although several example embodiments of the present technology have been described, those skilled in the art will readily recognize that many modifications are possible in the example embodiments without materially departing from the teachings and advantages of the present technology. Accordingly, all such modifications are intended to be included within the scope of the present technology as defined in the claims. The present technology is defined by the following claims, which will include equivalents of the claims.

Claims

1. An induction device, comprising: A spiral structure, the spiral structure including a first orifice; And A non-spiral structure, the non-spiral structure including a second orifice, Wherein, the first orifice and the second orifice define a passage, the passage being configured to receive a portion of the body of an inductively coupled plasma (ICP) torch, and wherein, the passage defines a longitudinal axis.

2. The induction device according to claim 1, wherein The spiral structure includes a spiral plate, and the non-spiral structure includes a flat plate.

3. The induction device according to claim 2, wherein, The spiral plate includes a body containing the first orifice and a first leg and a second leg extending away from the body, and wherein, the flat plate includes a body containing the second orifice and a first leg and a second leg extending away from the body.

4. The induction device according to claim 3, wherein The first leg of the spiral plate is axially spaced from the flat plate by a first distance, wherein, the second leg of the spiral plate is axially spaced from the flat plate by a second distance, and wherein, the second distance is greater than the first distance.

5. The induction device according to claim 4, wherein, The first distance is the minimum gap between the spiral plate and the flat plate, and the second distance is the maximum gap between the spiral plate and the flat plate.

6. The induction device according to claim 4, wherein, The first distance is 2 to 3 mm, and the second distance is 5 to 6 mm.

7. The induction device according to claim 3, wherein, The first leg of the spiral plate is axially aligned with the second leg of the flat plate, and wherein, the second leg of the spiral plate is laterally offset from the flat plate relative to the longitudinal axis.

8. The induction device according to claim 7, wherein, The second leg of the spiral plate and the first leg of the flat plate are each configured to be supplied with radio frequency current, and wherein, the first leg of the spiral plate and the second leg of the flat plate are configured to be connected to ground.

9. The induction device according to claim 7, further comprising a spacer between the first leg of the spiral plate and the second leg of the flat plate.

10. The induction device according to claim 9, wherein, The spacer contacts each of the first leg of the spiral plate and the second leg of the flat plate.

11. The induction device according to claim 7, further comprising an electrode connected to each of the second leg of the spiral plate, the first leg of the flat plate, and the second leg of the flat plate.

12. The induction device according to claim 11 further includes a conductive plate, wherein the spiral plate and the flat plate are coupled to the conductive plate, where The electrode and the conductive plate are configured as heat sinks to facilitate cooling of the spiral plate and the flat plate.

13. The induction device according to claim 3, wherein, The body of the spiral plate is in the shape of a ring and makes substantially a single rotation or turn between the first leg and the second leg of the spiral plate.

14. The induction device according to claim 2, wherein, The spiral plate and the flat plate each have a thickness of about 2 mm.

15. The induction device according to claim 2, wherein, The spiral plate has a pitch of 4 to 6 mm per revolution.

16. The induction device according to claim 1, wherein, The spiral structure includes a coil.

17. The induction device according to claim 15, wherein, The coil is a single coil.

18. The induction device according to claim 1, wherein, The spiral structure and / or the non-spiral structure is formed of aluminum.

19. The induction device according to claim 1, wherein, The spiral structure and / or the non-spiral structure is formed of copper.

20. An inductively coupled plasma (ICP) torch, comprising; A syringe configured to receive a flow of sample fluid; A plurality of tubes disposed around the syringe and configured to receive and direct a flow of one or more torch gases; And An induction device disposed around at least one of the plurality of tubes, the induction device configured to receive a radio frequency current to inductively excite at least one of the one or more torch gases to generate a plasma near a distal end of the ICP torch. Wherein, the induction device includes: A spiral structure including a first orifice; and A non-spiral structure including a second orifice, Wherein, the first orifice and the second orifice define a passage configured to receive at least one of the plurality of tubes, and wherein the passage defines a longitudinal axis.

21. The ICP torch according to claim 20, wherein, The spiral structure includes a spiral plate, and the non-spiral structure includes a flat plate.

22. The ICP torch according to claim 21, wherein, The spiral plate includes a body containing the first orifice and first and second legs extending away from the body, and wherein the flat plate includes a body containing the second orifice and first and second legs extending away from the body.

23. The ICP torch according to claim 22, wherein, The first leg of the spiral plate is axially spaced from the flat plate by a first distance, wherein the second leg of the spiral plate is axially spaced from the flat plate by a second distance, and wherein the second distance is greater than the first distance.

24. The ICP torch according to claim 23, wherein, The first distance is the minimum gap between the spiral plate and the flat plate, and the second distance is the maximum gap between the spiral plate and the flat plate.

25. The ICP torch according to claim 23, wherein, The first distance is 2 to 3 mm, and the second distance is 5 to 6 mm.

26. The ICP torch according to claim 22, wherein, The first leg of the spiral plate is axially aligned with the second leg of the flat plate, and wherein the second leg of the spiral plate is laterally offset from the flat plate relative to the longitudinal axis.

27. The ICP torch according to claim 26, wherein, The second leg of the spiral plate and the first leg of the flat plate are each configured to be supplied with a radio frequency current, and wherein the first leg of the spiral plate and the second leg of the flat plate are configured to be connected to ground.

28. The ICP torch according to claim 26, further comprising a spacer between the first leg of the spiral plate and the second leg of the flat plate.

29. The ICP torch according to claim 28, wherein, The spacer contacts each of the first leg of the spiral plate and the second leg of the flat plate.

30. The ICP torch according to claim 26, further comprising an electrode connected to each of the second leg of the spiral plate, the first leg of the flat plate, and the second leg of the flat plate.

31. The ICP torch according to claim 30 further includes a conductive plate, wherein the spiral plate and the flat plate are coupled to the conductive plate, where The electrode and the conductive plate are configured as heat sinks to facilitate cooling of the spiral plate and the flat plate.

32. The ICP torch according to claim 22, wherein, The body of the spiral plate is in the shape of a ring and makes substantially a single rotation or turn between the first leg and the second leg of the spiral plate.

33. The ICP torch according to claim 21, wherein, The spiral plate and the flat plate each have a thickness of about 2 mm.

34. The ICP torch according to claim 21, wherein, The spiral plate has a pitch of 4 to 6 mm per revolution.

35. The ICP torch according to claim 20, wherein, The spiral structure includes a coil.

36. The ICP torch according to claim 35, wherein, The coil is a single coil.

37. The ICP torch according to claim 20, wherein, The spiral structure and / or the non-spiral structure is formed of aluminum.

38. The ICP torch according to claim 20, wherein, The spiral structure and / or the non-spiral structure is formed of copper.

39. The ICP torch according to claim 21, wherein, The plurality of tubes includes: An intermediate tube, the intermediate tube being disposed around the syringe, wherein the syringe and the intermediate tube define an auxiliary gas passage configured to receive a flow of auxiliary gas; and A plasma tube, the plasma tube being disposed around the intermediate tube, wherein the intermediate tube and the plasma tube define a plasma gas passage configured to receive a flow of plasma gas.

40. The ICP torch according to claim 39, wherein, The maximum axial gap between the distal end of the intermediate tube and the spiral plate is 4.9 to 5.1 mm.

41. The ICP torch according to claim 39, wherein, The axial gap between the distal end of the syringe and the distal end of the intermediate tube is 2 to 3 mm.

42. An inductively coupled plasma optical emission spectroscopy (ICP-OES) system comprising an ICP torch according to any one of claims 20 to 41.

43. A method for generating a plasma, the method comprising: Providing an inductively coupled plasma (ICP) torch, the inductively coupled plasma (ICP) torch comprising: A syringe tube, the syringe tube including a syringe flow passage for receiving a flow of sample fluid; An intermediate tube, the intermediate tube being disposed around the syringe tube, wherein the syringe and the intermediate tube define an auxiliary gas passage configured to receive a flow of auxiliary gas; A plasma tube, the plasma tube being disposed around the intermediate tube, wherein the intermediate tube and the plasma tube define a plasma gas passage configured to receive a flow of plasma gas; and An induction device, the induction device including a spiral structure and a non-spiral structure, the spiral structure including a first orifice, the non-spiral structure including a second orifice, wherein the first orifice and the second orifice define a passage configured to receive the plasma tube; Flowing the auxiliary gas through the auxiliary gas passage; Flowing the plasma gas through the plasma gas passage; and Supplying a radio frequency current to the induction device to inductively excite the auxiliary gas to generate a plasma near the distal end of the torch.

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