Water-carrying atomic fluorescence analysis device and atomic fluorescence analysis method

Abstract

The water-carrying atomic fluorescence analysis device and analysis method of the present invention belong to the atomic fluorescence analysis in the field of analytical chemistry. The analysis device includes an infusion system with water as the carrier and an instrument body. The instrument body includes a shell and a reactor, an atomizer, an optical circle, an excitation light source, a detector, a circuit and gas circuit integrated system and a lamp position adjustment device assembled in the shell. Water is used as the carrier during the infusion process, and samples are introduced from the quartz furnace outer tube of the atomizer during the atomization process. The hydrogen flame is controlled to burn intermittently and the atomic fluorescence is detected synchronously to complete the detection. The device of the present invention is highly integrated and compact in structure, and is easy to assemble, adjust, operate and maintain. The analysis method of the present invention can effectively overcome the memory effect, improve the sensitivity and accuracy of the measurement, and break through the constraints of traditional atomic fluorescence analysis. It is an innovation in atomic fluorescence analysis technology.

Description

Technical Field

[0001] The invention belongs to the field of analytical chemistry and relates to atomic fluorescence analysis. It breaks through the atomic fluorescence analysis technology and specifically relates to the improvement of the existing atomic fluorescence instrument and atomic fluorescence analysis method. Background Art

[0002] Atomic fluorescence analysis has been widely used in the determination of trace amounts of As, Sb, Bi, Hg, Se and other elements. The basic principle is that the ions of the element to be measured react with a strong reducing agent (usually potassium borohydride or sodium borohydride) in an acidic medium (usually hydrochloric acid) to be reduced to gaseous hydrides or atoms, while producing a large amount of hydrogen. The hydride molecules dissociate into ground state atoms in a high-temperature hydrogen flame and are excited to a high-energy state by the radiation of a specific frequency of the excitation light source. Since the high energy level is extremely unstable, the excited state atoms emit fluorescence of a characteristic wavelength in the form of light radiation during the de-excitation process. The fluorescence intensity is related to the concentration of the element to be measured, and the concentration of the element to be measured is obtained by measuring its fluorescence signal through a detector (usually a photomultiplier tube).

[0003] The atomic fluorescence analysis device (also called atomic fluorescence instrument, atomic fluorescence photometer) designed according to the above principle mainly includes an infusion system, a steam generation system (or reactor), an atomizer, an excitation light source, a detector and a control system. The infusion system is used to transmit the test solution and the reducing agent, a chemical reaction occurs in the steam generation system to generate gaseous hydride molecules and hydrogen (becomes steam), the atomizer is used to make the hydride molecules into atoms, the excitation light source and the detector are used to generate fluorescence and collect fluorescence signals, and the detection results are reported through the operation of the control system.

[0004] Since the advent of commercial instruments, atomic fluorescence analysis has used HCl-NaBH4 (NaBH4) as a carrier to transport the test solution, and the reaction product is introduced into the hydrogen flame from the inner tube of the quartz furnace along with a small flow of Ar gas. The Ar gas introduced into the outer tube acts as a shield and is called shielding gas. The hydrogen gas continuously generated during the measurement process maintains the hydrogen flame, resulting in the consumption of a large amount of high-purity HCl and reducing agent, which in turn brings about problems such as long injection and measurement time, high furnace temperature, large memory effect, no complete signal spectrum, and frequent difficulty in igniting the hydrogen flame. At the same time, most of these instruments do not have a suitable lamp position adjustment device; the electromagnetic valve used to control the carrier gas often fails; the operating software is complicated; and a large lamp current and negative high voltage are required to achieve higher sensitivity. All of the above have a negative impact on the use of atomic fluorescence detection. Summary of the invention

[0005] The present invention aims to provide an atomic fluorescence analysis device with a completely new concept to effectively solve the above problems.

[0006] The water-carrying atomic fluorescence analysis device provided by the present invention comprises an infusion system and an instrument body, wherein the instrument body comprises an outer shell and a reactor, an atomizer, an optical circle, an excitation light source, a detector and a circuit and gas circuit integrated system etc. which are assembled in the outer shell, and the infusion system comprises: a test liquid bottle for holding a test liquid, the test liquid bottle is connected with the reactor through a sample inlet tube; a reagent bottle for holding a reducing agent, the reagent bottle is connected with the reactor through a reagent inlet tube; a water bottle for holding pure water, the water bottle outlet is connected with the sample inlet tube inlet and the reagent inlet tube inlet respectively through a water inlet tube, and the water inlet is controlled by switching the water inlet tube; and the infusion system does not contain a matching device for infusing the carrier acid.

[0007] In the water-carrying atomic fluorescence analysis device, the sample inlet tube and the reagent inlet tube are both liquid inlet capillaries, the water bottle is changed to two water cups, one water cup is used to hold cleaning water, and the other water cup is used to hold carrier water, and the liquid inlet capillaries are replaced in the two water cups.

[0008] In the water-carrying atomic fluorescence analysis device, the liquid inlet capillary is connected to the reactor through a peristaltic pump, and the peristaltic pump controls the delivery speed and infusion volume of the test solution, reducing agent, cleaning water and carrier water into the liquid inlet capillary.

[0009] In the water-carrying atomic fluorescence analysis device, the gas outlet pipeline of the reactor is connected to the outer pipe joint of the quartz furnace in the atomizer, and the inner pipe joint of the quartz furnace is connected to the argon gas pipeline as auxiliary gas.

[0010] In the water-carrying atomic fluorescence analysis device, the atomizer includes a furnace body support, a furnace core, a quartz furnace mounted in the furnace core, and a furnace body outer cover mounted outside the furnace core, a ceramic cover plate, an electric furnace wire and other components. It is characterized in that the furnace core and the furnace body outer cover are made of insulating and heat-resistant non-metallic materials, and the components are snap-fitted or fixed without screws.

[0011] In the water-carrying atomic fluorescence analysis device, at least two slots are arranged on the upper end of the furnace body outer cover, and buckles are arranged on the side of the ceramic cover plate. The buckles are engaged with the slots to clamp the upper end of the furnace body outer cover with the ceramic cover plate.

[0012] In the water-carrying atomic fluorescence analysis device, the electric furnace wire is inserted and embedded between the ceramic cover plate and the tube mouth of the quartz furnace. A ceramic insulation layer instead of asbestos is provided between the ceramic cover plate and the top surface of the furnace core. The ceramic insulation layer supports the electric furnace wire and positions it at the tube mouth of the quartz furnace.

[0013] In the water-carrying atomic fluorescence analysis device, a groove body and a step are arranged on the upper part of the furnace body support, and two slot holes are opened on the side wall of the groove body; a protrusion is arranged on the lower part of the furnace core, and the protrusion is embedded in the groove body; the inner pipe joint and the outer pipe joint of the lower part of the quartz furnace are clamped in the slot holes and extend sideways; the quartz furnace is sleeved in the furnace core cavity, and the pipe mouth of the quartz furnace extends upward from the top end surface of the furnace core; the furnace body outer cover is sleeved on the outer periphery of the furnace core, and the bottom of the furnace body outer cover is seated on the step of the furnace body support.

[0014] In the water-borne atomic fluorescence analysis device, the optical circle includes a shell, one side of which is provided with mounting holes for mounting an excitation light source and a detector respectively, and a side cut groove is provided on the opposite side of the shell to the mounting hole for transmitting light emitted by the excitation light source.

[0015] In the water-borne atomic fluorescence analysis device, the size of the side cut groove matches the adjustment range of the excitation light source, so that the characteristic spectrum emitted by the excitation light source will not be irradiated onto the housing of the optical circle.

[0016] In the water-borne atomic fluorescence analysis device, light-absorbing paper coated with black light-absorbing material is laid on the inner side of the atomic fluorescence instrument shell, and the side cut groove of the shell faces the light-absorbing paper.

[0017] In the water-borne atomic fluorescence analysis device, the circuit and gas circuit integration system is an integral module, including a base plate, a switching power supply installed on the base plate, and a vertical frame type circuit and gas circuit integration module. The vertical frame type circuit and gas circuit integration module includes a power supply board, a control main board and a support board with fixed spacing in the vertical direction. The support board is installed with a gas control module and a gas pressure gauge. The control main board controls the flow of the gas channel of the gas control module; the power supply board modulates the power provided by the switching power supply into DC power of different ranges to supply the control main board and the gas control module.

[0018] In the water-carrying atomic fluorescence analysis device, the bottom plate and the bottom of the instrument body are nested with slide rails and grooves to achieve displacement.

[0019] In the water-borne atomic fluorescence analysis device, a large display screen is arranged on the front panel of the instrument main body shell for displaying the desktop system content.

[0020] In the water-carrying atomic fluorescence analysis device, the instrument body also includes a lamp position adjustment device for adjusting the excitation light source in the horizontal and vertical directions, and the adjustment knob is located on the side of the instrument body shell.

[0021] In the water-borne atomic fluorescence analysis device, the lamp tube position adjustment device includes: a lamp tube holder for installing the lamp tube; a support seat, on the upper surface of which the lamp tube holder is installed; a horizontal adjustment mechanism, which is a gear combination structure, used to convert the rotation of the horizontal knob into the horizontal movement of the lamp tube holder installed with the lamp tube; a vertical adjustment mechanism, including a lead screw and a scissor-type structure connected to the lead screw through a lead screw nut assembly, used to convert the rotation of the lead screw into a change in the angle of the scissor-type structure, so as to promote the support seat supported on the scissor-type structure to move vertically up and down; a fixing frame, used to support the horizontal adjustment mechanism and the vertical adjustment mechanism.

[0022] Elastic clamping pieces are fixed on both sides of the lamp holder, the lower ends of the two clamping pieces are fixed on the sides of the lamp holder, and the upper ends are bent outwards, forming an arc-shaped storage space with an upper opening, which is narrow at the top and wide at the bottom, for installing the lamp.

[0023] The horizontal adjustment mechanism includes: a rack fixed to the bottom of the lamp holder; a spur gear provided with an integrated sleeve and meshing with the rack; a spur gear adjustment shaft, the lower end of which is rotatably mounted on a support beam, the two ends of the support beam are fixed to a fixing frame, the upper end of which is used to pass through the sleeve of the spur gear and is connected with the sleeve plane of the spur gear; two vertically arranged and meshing bevel gears, the horizontal bevel gear is fixed on the spur gear adjustment shaft, and the vertical bevel gear is fixed to the end of the bevel gear adjustment shaft; a horizontal knob is connected to the bevel gear adjustment shaft through a coupling.

[0024] The support seat includes a horizontal plate and a first side plate vertically arranged on both sides of the horizontal plate. The spur gear is fixed in a groove opened at the bottom of the lamp tube holder. A sliding sleeve is fixed on each side of the groove at the bottom of the lamp tube holder. The sliding sleeve can be slidably inserted into a third sliding groove opened on the horizontal plate.

[0025] The fixing frame comprises a base, support plates fixed to both ends of the base and second side plates arranged on both sides of the base, and the second side plates are provided with mounting holes and first sliding grooves for supporting the vertical adjustment mechanism.

[0026] The vertical adjustment mechanism includes: a scissor-type structure formed by two supporting links, a fixed rod is respectively passed through the two left corners of the scissor-type structure, and a sliding rod is respectively passed through the two right corners, and the two ends of the fixed rod are respectively fixed through the mounting holes of the second side plate and the first side plate; the two ends of the sliding rod can be slidably inserted into the second sliding groove of the second side plate and the first sliding groove of the first side plate respectively; a lead screw and a lead screw nut assembly that is inserted into the lead screw and threadedly connected with the lead screw, the lead screw head passes through the bearing, the support plate, and the lead screw nut assembly in turn and is fixed in the left bearing, the lead screw tail is connected to the vertical knob through a coupling, the upper end of the scissor-type structure formed by the two supporting links supports the horizontal plate of the support seat, and one sliding rod in the scissor structure can be slidably inserted into the second sliding groove of the second side plate after passing through the lead screw nut.

[0027] The atomic fluorescence analysis method provided by the present invention uses the aforementioned water-carrier atomic fluorescence analysis device, including the process of using the infusion system to take samples with water as carrier, and atomizing the samples from the outer tube of the quartz furnace until the detection is completed.

[0028] In the atomic fluorescence analysis method, the outer tube sampling refers to passing the hydride and hydrogen mixed gas carried by the carrier gas from the reactor into the outer tube of the quartz furnace, passing the auxiliary gas (Ar gas) into the inner tube of the quartz furnace, and controlling the flow rate.

[0029] In the atomic fluorescence analysis method, the flow rate of the carrier gas (which may also be Ar gas) carrying the mixed gas is increased to 1000-1200 ml / min, and the flow rate of the auxiliary gas (Ar gas) is reduced to 400-600 ml / min or no auxiliary gas is introduced (ie, the flow rate is 0 ml / min).

[0030] In the atomic fluorescence analysis method, the sampling refers to the simultaneous introduction of a test solution with a certain acidity (preferably a hydrochloric acid concentration range of 4%-10%) and a reducing agent with a certain concentration, and the water as a carrier refers to using pure water as a carrier to carry and push the test solution and the reducing agent into the reactor.

[0031] In the atomic fluorescence analysis method, the sampling time is 4-5 seconds, and the time from the water carrier flow to the end of the detection is 8-10 seconds.

[0032] In the atomic fluorescence analysis method, two cups are used to hold pure water. After sampling, the capillary for transporting the test solution and the reducing agent is swapped between the two cups of water. The sampling / delay / swapping / measurement times are 4-5 / 0 / 2-3 / 8-10 seconds, respectively, that is, the sampling time is 4-5 seconds, the delay is zero seconds, the swapping time is 2-3, and the time from carrying current to the end of measurement is 8-10 seconds.

[0033] In the atomic fluorescence analysis method, the detection process also includes a process of controlling the intermittent ignition of the hydrogen flame, and exciting the light source and the detector to work during the combustion time of the hydrogen flame.

[0034] By adopting the above scheme, the device of the present invention is highly integrated and compact in structure, and is easy to assemble, adjust, operate and maintain. The analysis method of the present invention can effectively overcome the memory effect, improve the measurement sensitivity and accuracy, and break through the constraints of traditional atomic fluorescence analysis. It is an innovation in atomic fluorescence analysis technology and has epoch-making significance.

[0035] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1A This is a schematic diagram of the overall appearance of the water-borne atomic fluorescence analysis device of the present invention;

[0037] Figure 1B This is a schematic diagram of the component structure of the water-carrying atomic fluorescence analysis device of the present invention;

[0038] Figure 2A It is a schematic diagram of the composition of the infusion system in the atomic fluorescence analysis device of the present invention;

[0039] Figure 2B It is a simplified infusion system structure and infusion schematic diagram in the atomic fluorescence analysis device of the present invention;

[0040] Figure 3A It is a schematic diagram of the structure of the atomizer components in the atomic fluorescence analysis device of the present invention;

[0041] Figure 3B It is a schematic diagram of the cross-sectional structure of the atomizer in the atomic fluorescence analysis device of the present invention;

[0042] Figure 3C It is a schematic diagram of the appearance structure of the atomizer in the atomic fluorescence analysis device of the present invention;

[0043] Figure 3D It is a schematic diagram of the external tube sample injection method of the present invention in atomic fluorescence analysis;

[0044] Figure 3E This is a schematic diagram of the original sampling method of the quartz furnace in atomic fluorescence analysis;

[0045] Figure 4-1 It is a three-dimensional structural diagram of the lamp position adjustment device in the atomic fluorescence analysis device of the present invention;

[0046] Figure 4-2 It is a schematic diagram of the structural decomposition of the lamp position adjustment device in the atomic fluorescence analysis device of the present invention;

[0047] Figure 4-3 It is a structural schematic diagram of the level adjustment mechanism in the atomic fluorescence analysis device of the present invention;

[0048] Figure 4-4 It is a structural schematic diagram of the vertical adjustment mechanism in the atomic fluorescence analysis device of the present invention;

[0049] Figure 4-5 It is a longitudinal cross-sectional view of the lamp position adjustment device in the atomic fluorescence analysis device of the present invention;

[0050] Figure 4-6 It is a schematic diagram of the cooperation between the lamp position adjustment device and the lamp in the atomic fluorescence analysis device of the present invention;

[0051] Figure 4-7 It is a schematic diagram of the state of the horizontal adjustment mechanism when the lamp holder in the atomic fluorescence analysis device of the present invention is in the highest position;

[0052] Figure 5-1This is a schematic diagram of the installation structure of the optical circle in the atomic fluorescence instrument;

[0053] Figure 5-2 This is the second schematic diagram of the installation structure of the optical circle in the atomic fluorescence instrument;

[0054] Figure 5-3 It is a schematic diagram of the three-dimensional structure of the optical circle in the atomic fluorescence analysis device of the present invention;

[0055] Figure 5-4 It is a rear view of the optical circle in the atomic fluorescence analysis device of the present invention;

[0056] Figure 5-5 It is a side view of the optical circle in the atomic fluorescence analysis device of the present invention;

[0057] Figure 6-1 It is a schematic diagram of the structure of the circuit and gas circuit integration system in the atomic fluorescence analysis device of the present invention;

[0058] Figure 6-2 yes Figure 6-1 Schematic diagram of the vertical frame structure in the circuit and gas circuit integrated system;

[0059] Figure 6-3 yes Figure 6-1 The schematic diagram of the circuit and gas circuit integrated system assembled in the atomic fluorescence spectrometer is shown;

[0060] Fig. 7A The peak curve (fluorescence value-time) of Cd was determined for detection example 1;

[0061] Figure 7B The 0.1-0.5 ng / mL standard curve (fluorescence value-concentration) of Cd was determined for detection example 1;

[0062] Fig. 8A To simultaneously determine the peak curve (fluorescence value-time) of Hg / As for detection example 2;

[0063] Figure 8B For the detection of Hg / As in Example 2, a standard curve (fluorescence value-concentration) of a mixed solution of 0.1-0.5 ng / ml Hg and 10-50 ng / ml As was obtained.

[0064] Fig. 9A The peak curve (fluorescence value-time) of Pb was determined for detection example 3;

[0065] Fig. 9B The 2-10 ng / mL standard curve (fluorescence value-concentration) of Pb was determined for detection example 3; DETAILED DESCRIPTION

[0066] Based on the original atomic fluorescence instrument, the present invention takes the adjustment of the sampling method of the infusion system as the starting point, combines the change of the sampling method of the atomizer quartz furnace, and cooperates with the improvement of various aspects such as assembly, adjustment, and automatic control of various components. Finally, a new atomic fluorescence device that breaks through the constraints of traditional concepts is proposed, and a new atomic fluorescence detection technology is formed.

[0067] Similar to the conventional atomic fluorescence analyzer, the atomic fluorescence analysis device of the present invention mainly includes an infusion system, a vapor generation system (or reactor), an atomizer, an excitation light source, a detector and a control system. The role and function of each part are the same as those of the original atomic fluorescence analyzer, but the present invention has a special design and unique combination, including:

[0068] J. Abolish the method of using HCl-NaBH4 as carrier and use pure water as carrier;

[0069] K. Use external tube injection technology;

[0070] L. Intermittent heating of the furnace wire;

[0071] M. Adopt the newly developed non-metal furnace body;

[0072] N. Use open optical circle;

[0073] O. Remove peripheral equipment and assemble in a centralized manner;

[0074] P. Abolish asbestos pads and use ceramic insulation layers;

[0075] Q. Adopt fast sampling and detection procedures; integrate measurement, display, printing, storage and fast desktop system;

[0076] R. Use a quick-adjustment device for light positions;

[0077] J. Use current limiting technology to allow ground state atoms or hydrides to pass into the quartz furnace at a slower speed.

[0078] The following explains them separately.

[0079] Infusion System

[0080] The characteristic A of the present invention is to use pure water as the carrier instead of HCl-NaBH4. Figure 2AAs shown, it includes: a test liquid bottle for holding a test liquid, the test liquid bottle is connected to the reactor through a sample inlet tube; a reagent bottle for holding a reducing agent, the reagent bottle is connected to the reactor through a reagent inlet tube; a water bottle for holding pure water, the water bottle outlet is connected to the sample inlet tube inlet and the reagent inlet tube inlet through a water inlet tube, respectively, and the water inlet is controlled by switching the water inlet tube. The unique design of the infusion system is that the infusion system does not include a supporting device for infusing hydrochloric acid, which is clearly distinguished and significantly different from the known infusion system.

[0081] Simplified infusion system see Figure 2B As shown, it includes: a test solution bottle for holding a test solution and a reagent bottle for holding a reducing agent, the test solution bottle and the reagent bottle are connected to the reactor through a liquid inlet capillary; two water bottles for holding pure water, one (water cup 1) holds cleaning water for cleaning the capillary, and the other (water cup 2) holds carrier water as a carrier. A peristaltic pump can be used in the atomic fluorescence analysis infusion process. After the test solution and the reducing agent are respectively input into the sample storage loop (called "sampling") through two capillaries under the action of the peristaltic pump, the front section of the two capillaries near the head end is transferred to the cleaning pure water in the water cup 1 for cleaning (see Figure 2B Then the two capillary tips are transferred into the water cup 2 (see Figure 2B The midpoint line is called "insertion"), and the test solution and reducing agent in the sample loop are pushed into the reactor with carrier pure water.

[0082] Using this simplified infusion system, after delivering the test solution and reducing agent, the capillary is immediately placed in the first cup of water (cup 1) to clean the solution that may be stained on the outer wall, and then placed in the second cup of water (cup 2) to carry the taken solution with water until the measurement is completed. The specific operation can be:

[0083] A1) Sampling: insert the two inlet capillary ends into the test solution (blank solution, standard solution or sample solution) and reducing agent (NaBH4) solution respectively to take samples, and the peristaltic pump stops working after 4-5 seconds;

[0084] A2) Replacement: Take out the two capillary ends and place them in a cup of cleaning water to clean them, then transfer them to another cup of carrying water, and restart the peristaltic pump;

[0085] A3) Carrier water measurement: Carrier water carries the test solution and reducing agent into the reactor, and the instrument measures the fluorescence signal of the test solution at the same time.

[0086] In this operation, the sampling / delay / switch time / measurement time is 4-5 / 0 / 2-3 / 8-10 seconds respectively, that is, A1) sampling time is 4-5 seconds, delay is zero second, A2) swap time is 2-3, A3) current measurement time is 8-10 seconds.

[0087] The present invention utilizes the infusion system to creatively use water as a carrier in atomic fluorescence analysis, ending the history of using HCl and NaBH4 as carriers for more than 30 years, and can detect trace or trace amounts of As, Sb, Bi, Pb, Se, Cd, and Hg in the test solution, indicating that the infusion technology using water instead of HCl and a reducing agent as a carrier can be used in atomic fluorescence analysis, and its beneficial effects are: unlike HCl and NaBH4 as carriers, ultrapure water does not contain the measured component, and will not have any chemical reaction with the test solution or the reducing agent during the infusion process, and there is no large amount of bubbles (caused by the generation of hydrogen by the acid and the reducing agent) adhering to the pipe wall of the flow path, so that all the infusion flow paths can be flushed most thoroughly. Therefore, the atomic fluorescence analysis using water as a carrier effectively overcomes the memory effect, improves the sensitivity and accuracy of the determination, and saves a large amount of high-purity HCl and the reducing agent NaBH4, greatly reduces the analysis cost, and significantly improves the operating environment.

[0088] Atomizer

[0089] Feature D of the present invention is the use of a newly developed non-metallic furnace body, feature G is the use of a ceramic insulation layer instead of asbestos pad, feature B is the use of external tube injection technology, feature J is the current limiting technology, and feature C is the intermittent heating of the furnace wire. These features are reflected in the improvement and use of the atomizer.

[0090] Features D and G relate to the novel atomizer 30 designed by the present invention, and its appearance and structure are shown in FIG. Figure 1B and Figure 3C , its composition and structure refer to Figure 3A-3CAs shown, it includes: a furnace core 31, a quartz furnace 33 mounted inside the furnace core 31, a furnace body outer cover 32 mounted outside the furnace core 31, a ceramic cover plate 34 clamped with the upper end of the furnace body outer cover, an electric furnace wire 37 embedded between the ceramic cover plate 34 and the pipe mouth of the quartz furnace 33, and a ceramic heat insulation layer 36 filled between the ceramic cover plate 34 and the top surface of the furnace core 31. The above components constitute the furnace body part, and a furnace body support 35 is provided at the bottom of the furnace body for supporting the furnace body. Here: the quartz furnace 33 is an existing commercial product, which is a sleeve composed of a central tube (inner tube) and an outer tube separated from each other. The inner tube and the outer tube are connected to the hydride and hydrogen (carried by the carrier gas) and the shielding gas produced by the reactor through an inner tube joint 331 and an outer tube joint 332 respectively. The furnace core 31 is an I-shaped cavity component as a whole, and a quartz furnace 33 is mounted in the cavity. The pipe mouth 333 of the quartz furnace extends upward from the top surface 313 of the furnace core 31. The shape and size of the lower protrusion 311 of the furnace core 31 match the upper groove 351 of the furnace body support 35, and the protrusion 311 is embedded in the groove 351. An inner groove can be provided on the upper part of the furnace core 31 to accommodate the ceramic heat insulation layer 36. Two slots 352 are provided on the side wall of the upper groove 351 of the furnace body support 35, and the inner pipe joint 331 and the outer pipe joint 332 of the quartz furnace 33 extend to the side through the slots 352. The outer cover 32 of the furnace body is cylindrical and is mounted on the outer periphery of the furnace core 31. Its bottom 321 is seated on the step 353 of the furnace body support, and at least two card slots 322 are provided on the upper part, which are card-fitted with the card buckle 342 provided on the side of the ceramic cover plate 34. The electric furnace wire 37 is sleeved and installed on the inner side of the ceramic cover plate 34, and is supported and fixed around the pipe mouth 333 of the quartz furnace 33 by the ceramic insulation layer 36 filled between the ceramic cover plate 34 and the top surface of the furnace core 31. The shape of the ceramic insulation layer 36 varies with the shape of the filled gap, and one or more insulation materials such as ceramic sheets, ceramic fibers, and mica sheets can be selected (without asbestos materials), such as Figure 3B A ceramic heat insulation layer is shown which is composed of ceramic fiber ropes 363 , mica sheets 362 and ceramic fibers 361 stacked in sequence, wherein the ceramic fiber ropes 363 are embedded in an inner groove opened in the upper part of the furnace core 31 .

[0091] The above components are assembled as follows: the upper part of the quartz furnace 33 is inserted into the inner cavity of the furnace core 31 from bottom to top, the furnace core 31 and the bottom of the quartz furnace 33 are inserted into the upper groove 351 of the furnace body support, and the inner pipe joint 331 and the outer pipe joint 332 of the quartz furnace 33 are clamped into the groove 352; the ceramic cover plate 34 with the electric furnace wire 37 is clamped on the upper end of the furnace body cover 32, and the ceramic insulation layer 36 is filled in the space from the upper end of the furnace core 31 to the pipe mouth of the quartz furnace 32, and finally the furnace body cover 32 is sleeved outside the furnace core 31 and seated on the step 353 of the furnace body support 35. The atomizer obtained by the assembly is assembled using structures such as card slots to achieve the fixation between components without screws.

[0092] In the atomizer, the furnace core 31 and the furnace outer cover 32 are made of insulating and heat-resistant non-metallic materials, and no metal materials are used. The furnace body is made of non-metallic materials with excellent heat dissipation performance and complete insulation. After stopping work, it can be repaired without cooling, and the temperature of the furnace body will not be too high during operation, which overcomes the phenomenon of baseline drift, and the instrument has good working stability; the various components are assembled together, and no screws are required during installation, and the whole can be disassembled and repaired; the quartz furnace tube mouth is made of thermal insulation materials such as mica and ceramics, which eliminates carcinogenic asbestos and improves the quality of the atomizer as a whole.

[0093] In terms of using the atomizer, feature D relates to the unique external tube injection method proposed by the present invention, and feature J further combines the use of current limiting technology. Figure 3D Shown and Figure 3E In comparison, the present invention connects the hydride and hydrogen mixed gas (generated in the gas-liquid separator) carried by the carrier gas (argon gas) originally connected to the inner tube of the quartz furnace to the outer tube, and at the same time connects the shielding gas (Ar gas) tube of the outer tube to the inner tube as an auxiliary gas; on the other hand, the flow rate of the carrier gas (also Ar gas) carrying the mixed gas is increased to 1000-1200ml / min, and the shielding gas flow rate (Ar gas volume) is reduced from 1000ml / min of the original method to 400-600ml / min, and some elements can be measured even without the auxiliary gas (i.e. 0ml / min). The application of current limiting technology allows the ground state atoms or hydrides to pass to the quartz furnace at a slower speed, which can make the hydrogen flame more stable and maintain for a longer time.

[0094] The outer tube injection method has changed the traditional mode of introducing hydrides (or Hg atoms) through the inner tube in atomic fluorescence analysis. The mechanism is as follows: the gaseous atoms or molecules and hydrogen produced by the chemical reduction reaction are introduced from the outer tube of the quartz furnace along with the carrier gas Ar gas. The hydride of the element to be measured (or mercury atoms) and the hydrogen mixture rise along the inner wall of the outer tube of the quartz furnace. The hydrogen is immediately ignited by the heat at the mouth of the quartz furnace tube, and the hydride is dissociated under the high temperature of the hydrogen-oxygen flame in the Ar gas atmosphere. The auxiliary gas (usually argon) entering the inner tube pulls the hydrogen flame upward, and the hydrogen flame formed is much larger than that of the inner tube injection (see Figure 3D As shown). In this way, the hydrogen is heated by the furnace wire located at the mouth of the outer tube, and the hydrogen flame is very easy to ignite. The hydrogen flame formed is large and stable, and the measurement sensitivity is significantly improved. It is also particularly suitable for the detection of elements (such as Pb) that produce less hydrogen in the reaction.

[0095] In short, the external tube injection technology makes it very easy to ignite the hydrogen flame, and the flame shape is large, the luminous solid angle is large, and the sensitivity is high; it is particularly beneficial for reaction systems that produce less hydrogen, such as the determination of Pb.

[0096] Characteristic C involves a change in the heating method of the furnace wire, changing the original method of maintaining a continuous hydrogen flame during the analysis process to intermittent heating. Intermittent heating means that when measuring the signal, the hydrogen flame is only ignited for a period of time, and the furnace is in a cooling period for about half of the time. In this way, the phenomenon of baseline drift caused by the increase in furnace temperature in atomic fluorescence analysis is overcome.

[0097] Lamp position adjustment device

[0098] The characteristic I of the present invention is the rapid adjustment of the lamp position. The vertical and horizontal positions of the emitting light source (hollow cathode lamp) can be quickly adjusted by two knobs outside the chassis. This characteristic is achieved by the specially designed lamp position adjustment device 60 (see Figure 1B ). In view of the problems of inconvenient operation and difficulty in ensuring the position of the lamp tube in the existing lamp position adjustment device using screws, the present invention proposes a lamp position adjustment device that is easy to operate and can achieve continuous adjustment. The position adjustment device uses a gear combination structure to convert the rotation of a horizontal knob into horizontal movement of a lamp holder on which the lamp tube is installed, and uses a lead screw and a scissor-type structure connected to the lead screw to convert the rotation of the lead screw into a change in the angle of the scissor-type structure, thereby promoting the vertical movement of a support seat supported on the scissor-type structure.

[0099] The structure of the lamp position adjustment device can be found in Figure 4-1 to Figure 4-7 , the numbers in the figure are:

[0100] 01: lamp holder, 011: sliding sleeve;

[0101] 02: fixed frame, 021: base, 022: support plate, 023: second side plate, 0231: second slide groove;

[0102] 03: support seat, 031: horizontal plate, 0311: third slide slot; 032: first side plate, 0321: first slide slot;

[0103] 04: horizontal adjustment mechanism, 041: rack, 042: spur gear, 043: spur gear adjustment shaft, 044: bevel gear, 045: bevel gear adjustment shaft, 046: support beam, 047: horizontal knob;

[0104] 05: vertical adjustment mechanism, 050: scissor structure, 051: supporting connecting rod, 052: fixing rod, 053: sliding rod, 054: lead screw, 055: lead screw nut assembly, 0551: lead screw nut, 0552: sleeve, 056: vertical knob;

[0105] 06: Clamping piece;

[0106] 07: Light tube.

[0107] See also Figure 4-1 and Figure 4-5 The lamp position adjustment device of the present invention is used to install the lamp 07 as an excitation light source and adjust its position so that the excitation spectrum emitted by the lamp 07 irradiates the center of the flame ignited at the outlet of the atomizer. The lamp position adjustment device includes a horizontal adjustment mechanism 04, a vertical adjustment mechanism 05, a support seat 03, a lamp holder 01, and a fixing frame 02 for supporting the horizontal adjustment mechanism 04 and the vertical adjustment mechanism 05. The lamp 07 is fixed on the lamp holder 01 by a clamping piece 06 (see Figure 4-6 ), the lamp holder 01 is installed on the support seat 03, the horizontal adjustment mechanism 04 adopts a gear combination structure to convert the rotation of the horizontal knob 047 into the horizontal movement of the lamp holder 01 installed with the lamp 07, and the vertical adjustment mechanism 05 adopts a screw 054 and a scissor-type structure connected to the screw through a screw nut assembly 055, which converts the rotation of the screw 054 into a change in the angle of the scissor-type structure, thereby pushing the support seat 03 supported on the scissor-type structure to move vertically up and down.

[0108] like Figure 4-1 As shown, the lamp holder 01 is a block structure, with an arc-shaped groove at the upper end for accommodating the lamp 07. The lamp holder 01 is located on both sides of the arc-shaped groove and has elastic clamping pieces 06 fixed thereto. The lower ends of the clamping pieces 06 are fixed to the sides of the lamp holder 01. The upper ends of the two clamping pieces are bent outward, and the two clamping pieces 06 form an arc-shaped storage space with an upper opening, which is narrow at the top and wide at the bottom. When installing, the lamp 07 is pressed downward from the opening of the arc-shaped storage space, and the clamping pieces 06 open outward due to elasticity. When the bottom of the lamp 07 contacts the arc-shaped groove of the lamp holder 01, the clamping pieces 06 rebound to clamp the lamp 07, thereby fixing the lamp 07.

[0109] Reference Figure 4-2 , Figure 4-3 and Figure 4-5The horizontal adjustment mechanism 04 includes a rack 041 fixed to the bottom of the lamp holder 01, a spur gear 042 meshing with the rack 041, a spur gear adjustment shaft 043 for fitting the spur gear 042, a bevel gear 044 fixed on the spur gear adjustment shaft 043, and a bevel gear 044 fixed on the bevel gear adjustment shaft 045, wherein the two bevel gears 044 are vertically arranged and meshed; the spur gear 042 is provided with an integrated sleeve, the sleeve is inserted into the upper part of the spur gear adjustment shaft 043 and connected by a plane fit, the spur gear 042 can rotate with the spur gear adjustment shaft 043, the lower end of the spur gear adjustment shaft 043 is rotatably mounted on a support beam 046, and the two ends of the support beam 046 are fixed on the fixed frame 02; the bevel gear adjustment shaft 045 is connected to the horizontal knob 047 through a coupling. The bevel gear 044 can transmit the rotational movement of the bevel gear adjustment shaft 045 through the bevel gear 044, driving the spur gear adjustment shaft 043 and the spur gear 042 to rotate, and then driving the rack 041 meshing with the spur gear 042 and the lamp tube holder 01 fixed to the rack 041 to move horizontally, thereby realizing the horizontal movement of the lamp tube 07 fixed to the lamp tube holder 01 by the clamping piece 06.

[0110] like Figure 4-2 As shown, the support seat 03 includes a horizontal plate 031 and first side plates 032 vertically arranged on both sides of the horizontal plate 031. The horizontal plate 031 is provided with a through hole for passing the spur gear adjustment shaft 043 (see Figure 4-5 ), a third slide groove 0311 is provided on each side of the through hole; a groove for accommodating a rack 041 and a spur gear 042 is provided at the bottom of the lamp tube holder 01, and the spur gear 042 is fixed in the groove of the lamp tube holder 01, and the spur gear 042 is meshed with the rack 041. At the same time, sliding sleeves 011 are fixed on both sides of the bottom groove of the lamp tube holder 01, and the sliding sleeves 011 can be slidably inserted into the third slide groove 0311. When the spur gear 042 rotates, it can drive the lamp tube holder 01 fixed to the rack 041 to move, and the sliding sleeve 011 slides in the third slide groove 0311.

[0111] like Figure 4-2 As shown, the fixing frame 02 serves as a supporting mechanism of the lamp position adjustment device, including a base 021, support plates 022 fixed to both ends of the base and second side plates 023 arranged on both sides of the base, and the second side plates 023 are provided with mounting holes and first slide grooves 0321.

[0112] Reference Figure 4-2 , Figure 4-4 and Figure 4-5The vertical adjustment mechanism 05 includes a scissor-type structure 050 formed by two supporting connecting rods 051, and the two left corners of the scissor-type structure 050 are respectively penetrated with a fixed rod 052, and the two right corners are respectively penetrated with a sliding rod 053. The two ends of the fixed rod 052 are respectively fixed through the mounting holes of the second side plate 023 of the fixing frame 02 and the first side plate 032 of the supporting seat 03, and the two ends of the sliding rod 053 can be slidably inserted into the second sliding groove 0231 of the second side plate 023 and the first sliding groove 0321 of the first side plate 032; the vertical adjustment mechanism 05 also includes a lead screw 054 and a lead screw 054 and a guide screw 053. The screw nut assembly 055 is threadedly connected, and the screw nut assembly 055 includes a screw nut 0551 and a sleeve 0552 connected to the screw nut. The head of the screw 054 passes through the right bearing, the support plate 022, and the sleeve 0552 of the screw nut assembly 055 in sequence and is fixed in the left bearing. The tail of the screw 054 is connected to the vertical knob 056 through a coupling. The upper end of the scissor-type structure formed by the two supporting connecting rods 051 supports the horizontal plate 031 of the support seat 03, and a sliding rod 053 in the scissor-type structure passes through the screw nut 0551 and can be slidably inserted into the second slide groove of the second side plate 023. When the vertical knob 056 is turned, the vertical knob 056 drives the screw 054 to rotate, and then drives the screw nut assembly 055 to move along the screw, thereby driving the horizontal angle of the scissor-type structure to increase or decrease, and the upper end of the scissor-type structure lifts or lowers the support seat 03, and at the same time, the sliding rod 053 moves in the corresponding slide groove.

[0113] The lamp position adjustment device assembled by the above components according to the above connection relationship has the following characteristics:

[0114] (1) The device adopts a gear combination structure, which converts the rotation of the bevel gear adjustment shaft 045 into the horizontal rotation of the spur gear adjustment shaft 043 and the spur gear 042 through the bevel gear 044, and then drives the lamp holder 01 equipped with the lamp 07 to move horizontally through the rack 041 meshing with the spur gear 042.

[0115] (2) In the vertical adjustment mechanism 05 of the device, the scissor-type structure composed of two supporting links 051 is connected to the lead screw 054 through the lead screw nut assembly 055. The lead screw 054 and the lead screw nut assembly 055 are threadedly connected. The relative movement of the lead screw 054 and the lead screw nut assembly 055 drives the angle of the scissor-type structure of the two supporting links 051 to change, thereby driving the support base 03 and the lamp tube base 01 supported at the upper end of the scissor-type structure to move vertically up and down. At the same time, the spur gear 042 moves up and down along the upper part of the spur gear adjustment shaft 043.

[0116] (3) The vertical adjustment mechanism 05 and the horizontal adjustment mechanism 04 are supported on the fixed frame 02, and the two are arranged crosswise in space without interference. The vertical adjustment mechanism 05 is connected to the second side plate 023 of the fixed frame 02 and the first side plate 032 of the support seat 03 through a fixed rod 052 arranged at the left corner of the scissor-like structure, and is slidably connected to the second side plate 024 of the fixed frame 02 and the first side plate 032 of the support seat 03 through a sliding rod 053 arranged on the right side of the scissor-like structure. The horizontal knob 047 and the vertical knob 056 of the device are both arranged outside the shell of the atomic fluorescence spectrometer, with a compact structure, convenient position adjustment, and continuous adjustment.

[0117] (4) The lamp tube 07 is fixed by two clamping pieces 06 fixed on the lamp tube holder 01. The lamp tube 07 is installed in the arc-shaped storage space formed by the two clamping pieces 06, which is narrow at the top and wide at the bottom. The elasticity of the clamping pieces 06 is used to clamp and fix the lamp tube 07. The lamp tube 07 only needs to be gently pressed and installed into the arc-shaped storage space formed by the clamping pieces to achieve automatic clamping and fixing without the need for additional operations.

[0118] Optical circle

[0119] The characteristic E of the present invention is to design an open optical circle 10 (see Figure 1B ), the radiation of the excitation light source (hollow cathode lamp) is moved out of the furnace, which can effectively reduce the influence of diffuse reflected light on the measurement, and make the installation and maintenance of the furnace more convenient. The lower opening of the optical circle is equipped with an atomizer, and the outlet of the atomizer is located inside the optical circle. One side of the shell of the optical circle is provided with a mounting hole for mounting the excitation light source and the detector, and a side cut groove is provided on the opposite side of the mounting hole. The characteristic spectrum emitted by the excitation light source is irradiated to the inner side of the atomic fluorescence instrument housing at a distance through the side cut groove, and no light enters the detector, thereby reducing optical interference, simplifying the structure, and facilitating installation and maintenance.

[0120] For installation and structure of the optical circle, see Figure 5-1 to Figure 5-5 As shown. The reference numerals in the figure are represented as follows:

[0121] 50: chimney, 30: atomizer;

[0122] 10: optical circle, 101: housing, 102: upper opening, 103: lower opening, 104: side cut groove, 105: first mounting hole, 106: second mounting hole, 107: third mounting hole;

[0123] 20: first excitation light source;

[0124] 20': second excitation light source;

[0125] 40: Detector.

[0126] like Figure 5-3 to Figure 5-5As shown, the optical circle 10 includes a shell 101, which is a cylindrical structure. The upper opening 102 and the lower opening 103 of the shell 101 are respectively used to install the chimney 50 and the atomizer 30. Three mounting holes are sequentially arranged on the same horizontal plane on one side of the shell 101, namely, a first mounting hole 105, a second mounting hole 106 and a third mounting hole 107, which are respectively used to install the first excitation light source 20, the detector 40 and the second excitation light source 20' (see Figure 5-2 ), a side cut groove 104 is opened on the opposite side of the mounting hole on the shell 101, and the size of the side cut groove 104 matches the adjustment range of the first excitation light source 20 and the second excitation light source 20', so that the characteristic spectrum emitted by the excitation light source can be irradiated to the inner side of the shell of the atomic fluorescence instrument through the side cut groove 104, and will not be irradiated to the shell 101.

[0127] During installation, the atomizer 30 extends into the housing 101 of the optical circle 10, the characteristic spectra emitted by the first excitation light source 20 and the second excitation light source 20' are directly opposite to the center of the flame ignited at the outlet of the atomizer 30, the optical path entrance of the detector 40 is located at the same horizontal plane as the center of the flame, and the emission ports of the first excitation light source 20 and the second excitation light source 20' and the optical path entrance of the detector 40 are directly opposite to the side cut groove 104 of the optical circle 10, and the side cut groove 104 faces the front cover plate 71 of the atomic fluorescence spectrometer (see Figure 1B ) inside (e.g., the rear side of the display screen 74). Preferably, light-absorbing paper coated with a black light-absorbing material is provided on the housing opposite to the side where the side cutout 104 of the optical circle 10 is located, and the light-absorbing paper can be directly attached to the inner side of the housing of the atomic fluorescence spectrometer, e.g., the rear side of the display screen.

[0128] When working, the characteristic spectrum emitted by the first excitation light source 20 and the second excitation light source 20' is directly irradiated to the back side of the display screen which is a distance away from the optical circle 10 through the side cut groove 104 of the optical circle 10, and the light basically does not enter the optical path entrance of the detector 40, and does not form stray light. After the light-absorbing paper is laid on the back side of the display screen, most of the light is absorbed to avoid reflection, thereby reducing the optical background.

[0129] The optical circle 10 designed in the present invention sets a side groove 104 on the opposite side of the emission port of the excitation light source and the optical path entrance of the detector 40, so that the characteristic spectrum emitted by the excitation light source is irradiated to the inner side of the shell of the atomic fluorescence instrument through the side groove 104, and stray light will not enter the detector, thereby reducing optical noise and preventing light diffusion from affecting the detection result; by providing the side groove 104 on one side of the optical circle 10, the emission mirror for removing stray light is omitted, the structure is simplified, and maintenance can be carried out without dismantling.

[0130] Circuit and gas circuit integration and control system

[0131] Feature F is that the atomic fluorescence instrument of the present invention has no peripheral equipment, and each component adopts a modular form, which can realize collective assembly. Feature H adopts a fast sampling and detection program, integrating measurement, display, printing, storage and a fast desktop system; the instrument not only has a neat appearance, a reasonable and compact internal configuration, and a small overall size, but also adopts an advanced electrical control system, with a large display screen 74 (see Figure 1B ) and a simple and clear desktop system, with sampling and measurement time of less than 20 seconds, and can be transported to the scene for emergency testing.

[0132] The circuit and gas circuit integrated system 80 of the present invention (see Figure 1B and Figure 6-1 ), which is mainly designed to solve the problems of inconvenient installation and maintenance, fast disassembly and assembly, and large space occupation caused by the horizontal arrangement of circuits and gas circuits in the original atomic fluorescence instrument. This system arranges the power board, control main board and gas control module in a vertical space through isolation columns to form a vertical frame-type circuit and gas circuit integrated module, which is then fixed on a base plate together with the switching power supply to form an integrated structure, which not only saves space but also facilitates disassembly and maintenance.

[0133] The composition of the circuit and gas circuit integrated system 80 is shown in Figure 6-1 to Figure 6-3 The reference numerals in the figure are as follows:

[0134] 810: vertical frame type circuit and gas circuit integrated module, 811: power board, 812: control main board, 813: support plate; 82: gas pressure gauge; 83: gas control module; 84: isolation column; 70: chassis; 86: switching power supply; 87: bottom plate.

[0135] See also Figure 6-1 to Figure 6-3 , the circuit and gas circuit integration system includes a base plate 87 and a switching power supply 86 and a vertical frame type circuit and gas circuit integration module 810 arranged on the base plate 87, and the switching power supply 86 supplies power to the vertical frame type circuit and gas circuit integration module 810.

[0136] like Figure 6-2As shown, the vertical frame type circuit gas path integrated module 810 is a vertical frame type modular structure, including a power board 811, a control main board 812 and a support board 813 which are arranged in sequence from bottom to top. A gas control module 83 and a gas pressure gauge 82 are installed on the support board 813. The gas control module 83 includes two gas channels, which are respectively used to transport carrier gas and auxiliary gas. The carrier gas and auxiliary gas are generally argon gas. The argon gas is connected to the gas channel of the gas control module 83 through a pipeline via a gas pressure gauge 82. The gas pressure gauge 82 is used to control the pressure of the introduced argon gas, which is generally controlled at 0.3 MPa. The control main board 812 (loaded with a control system) controls the flow of the two gas channels of the gas control module 83; the power provided by the switching power supply 86 is modulated into DC power of different ranges through the circuit of the power board 811 to supply the control main board 812 and the gas control module 83.

[0137] The vertical frame structure in the vertical frame type circuit and gas path integrated module 810 is not limited to three layers, and there is no restriction on the arrangement order between the layers and the distance between adjacent layers.

[0138] The bottom plate 87 can be fixed on the chassis 70 of the atomic fluorescence spectrometer. In order to facilitate the removal of the circuit and gas circuit integrated system 80 for maintenance or replacement of components, a raised track is provided at the bottom of the chassis 70, and a groove matching the raised track of the chassis 70 is provided on the bottom surface of the bottom plate 87. The bottom plate 7 can slide along the raised track of the chassis 70, slide in and out, and is convenient for installation and maintenance.

[0139] The circuit and gas circuit integrated system 80 is integrally built into the chassis 70 of the atomic fluorescence spectrometer. The power board 811, the control main board 812 and the support board 813 form a vertical frame structure through the isolation column 84. The switching power supply 86, the power board 811, the control main board 812 and the gas control module 83 are electrically connected through wires or flat wires. This vertical frame structure makes full use of the limited space in the chassis 70 and has a compact structure, which is conducive to the miniaturization of the atomic fluorescence spectrometer. The push-pull structure formed by the bottom plate 87 and the bottom of the chassis 70 is convenient for disassembly, assembly and maintenance.

[0140] The water-carrying atomic fluorescence analysis device of the present invention is assembled from components including the above systems. The appearance of the instrument body (excluding the infusion system) is as follows: Figure 1A As shown, the components are composed of Figure 1B The instrument housing includes a chassis 70, a rear cover 72, an upper cover 73 and a front cover 71. A large-size display screen 74 is installed on the front cover 71, through which the desktop operating system is displayed to realize human-computer dialogue; a peristaltic pump 91 of the infusion system is installed at the lower front part of the side panel of the chassis 70, and an argon gas delivery pipeline hole 92 is provided. A small printing output device can be installed on the other side (omitted on the right side of the figure), and a horizontal knob 047 and a vertical knob 056 (combined with the horizontal knob 056 of the lamp position adjustment mechanism) are installed at the upper part. Figure 4-1), the horizontal or vertical position of the lamp tube can be easily adjusted by the knob outside the chassis. The reactor 90 is installed in the chassis 70 adjacent to the peristaltic pump 91, and the test solution and reagent output pipes of the peristaltic pump 91 are connected to the reactor 90; a fixing frame 93 is fixed to the support frame in the chassis 70, and the atomizer 30 is installed on the fixing frame 93. The gas outlet pipeline of the reactor 90 is connected to the outer pipe joint of the quartz furnace of the atomizer 30, and the inner pipe joint of the quartz furnace is connected to the argon gas pipeline as the auxiliary gas; the optical circle 10 is sleeved on the outside of the atomizer 30 and fixed in the chassis 70, and the chimney 50 It is installed above the optical circle 10 and extends outward from the corresponding notch of the upper cover plate 73; the circuit and gas circuit integrated system 80 is installed as a whole at the bottom of the chassis 70, the lamp position adjustment device 60 and the excitation light source 20 (or 20') are installed and fixed on the support frame in the chassis 70 (the lamp can move horizontally or vertically), and the detector 40 is fixed on the support frame in the chassis 70; fix each component and connect the wires, install the front cover plate 71, the rear cover plate 72 and the upper cover plate 73, and the instrument body is assembled. The instrument body cooperates with the infusion system to form the water-carrying atomic fluorescence analysis device of the present invention.

[0141] When the water-carrying atomic fluorescence analysis device of the present invention is used to perform atomic fluorescence analysis, all analysis operation processes are completed on a display screen, and the display screen can display the structure, function and use method of the desktop system.

[0142] The desktop system is divided into five pages: "Home", "Settings", "Standard Curve Creation", "Sample Test" and "Instrument Performance Index Test". The "Home" recommends different element analysis conditions, and users use this as a reference. Before testing, they need to prepare the required test solutions and reagents.

[0143] The test is performed as follows:

[0144] 10 Turn on the power, select single channel (A or B) or dual channel (A+B) on the "Settings" page. Generally, Hg / As, As / Sb, Bi / Hg can be measured with dual channels; Se, Pb, Cd can be measured with single channel; set lamp current, negative high voltage; pump speed, Ar gas flow, and running time. In principle, no modification is required;

[0145] 11 Turn on the lamp power and preheat the hollow cathode lamp for 5-10 minutes. During this period, carefully adjust the light spot of the hollow cathode lamp. This light spot should be located in the center of the quartz furnace. Its height should be 8-10mm from the center of the lens aperture of the quartz furnace tube mouth. The specific number is related to the concentration of the element. For extremely low concentration samples, 8mm can be used for As and 10mm for Hg. The measurement of Hg / As should be based on the sample type. For example, for soil, the fluorescence value should be reduced.

[0146] 12. Open the main valve of the Ar gas cylinder, control the pressure of the first-stage pressure reducing valve to 0.4MPa, and the pressure of the second-stage pressure reducing valve to 0.3MPa; 13. After the instrument is preheated, open the ventilation, connect the electric furnace wire power supply, and place the test solution, reagents and two cups of water in the sample tray;

[0147] 14Insert the two infusion capillaries of the peristaltic pump into pure water respectively, click blank on the "Standard Curve Creation" page, clean the infusion flow path twice with test water, and then insert the capillary into the blank solution and NaBH4 solution. After sampling, immediately remove the capillary from the test solution and reagent solution, first place it in the first cup for quick cleaning, and then place it in the second cup of water. At this time, the pump inhales water, and the test solution and reagent are carried by the chemical reduction reaction. Hg atoms or hydrides are introduced into the hydrogen flame of the atomizer. The detector records the blank fluorescence value until the difference between the two measured values ​​is no more than 5, and then take the blank average value; then measure the fluorescence value of each solution in the series in order from low to high concentration (usually twice). Enter the concentration of the step series in the concentration column, click the average value and curve below, and the slope and intercept of the standard curve and linear equation can be displayed.

[0148] 15After making the standard curve, determine the sample concentration on the "Sample" page. Before determining the test solution, the capillary needs to be inserted into the water again, cleaned twice according to the running program, and then the fluorescence value of the blank is determined with the standard blank and reagent blank solutions and the average is taken. Then the fluorescence value of each test solution is determined one by one, and the corresponding test solution concentration is obtained. In the corresponding column, enter the sample weight or sampling volume and the volume fraction of the preparation solution, and click "enter" to obtain the content of the sample to be tested. If the number of samples exceeds 10, continue the test with pages 2-4.

[0149] 16 Enable the print or store button on the right to print or store the standard curve or sample results. The stored data can be read out or saved on the computer.

[0150] 17 After the test, the flow path needs to be cleaned with water 2-3 times.

[0151] 18 Turn off the hollow cathode lamp, furnace filament power supply, Ar gas, ventilation and host power supply one by one and loosen the peristaltic pump clamp, and finally close the Ar gas cylinder valve.

[0152] The above operation is used to test the effect of using the device of the present invention to perform element atomic fluorescence analysis. The reagent concentration "%" in the example is expressed as mass percentage concentration.

[0153] Detection Example 1: Analysis of Cd

[0154] Test samples: rice, soybeans

[0155] Preparation of cadmium standard curve: First prepare 10ng / ml cadmium standard solution (prepared now), then take 0, 0.5, 1.0, 1.5, 2.0, 2.5ml of this standard solution in 50ml plastic quantitative bottles, add 4ml of 50% HCl solution and 5ml of 5% thiourea to each solution, dilute to the scale with water, the concentration of this standard series solution is 0, 0.1, 0.2, 0.3, 0.4, 0.5ng / ml Cd. After shaking well, measure the fluorescence signal of blank and standard series solutions according to the operation process, and prepare the standard curve (see Figure 7B ), Fig. 7A The peak curve of Cd is shown.

[0156] Preparation and determination of test solution:

[0157] Weigh 0.1-0.2g of rice or soybean sample, place in a 50ml plastic quantitative bottle, add 4ml of 50% HCl and 5ml of 5% thiourea, shake for 5-10min, dilute to scale with water, shake well and use the sample solution as the test solution to measure the fluorescence signal of the sample solution according to the operation process, obtain the Cd concentration from the standard curve and convert it into the content in the sample. The determination results of Cd in food samples are shown in Table 1.

[0158] Table 1. Test results of Cd in rice and soybean powder (ng / g)

[0159]

[0160] From the data in the table, it can be seen that when the sample weight (G) varies greatly and the HCl concentration is 4%, the test sample is not pre-treated, and the use of water-based atomic fluorescence analysis can quickly determine the cadmium in rice and other foods. The measured Cd content in the sample is consistent with the recommended value.

[0161] In this determination operation, only pure water (18.2MΩ) is consumed without hydrochloric acid as a carrier, and the sampling time is reduced by about 50% compared with the conventional method. The NaBH4 solution is only needed to participate in the reaction, which saves more than 75% compared with conventional detection. The sample detection in Table 1 is measured from left to right. It can be seen that the concentration of cadmium in the solution can still be determined from high to low and the measurement results are accurate. It can be seen that using water as a carrier eliminates the memory effect. Even after the high-concentration standard solution is measured, the infusion system is cleaned by the carrier water, and the measurement of other concentration sample solutions is not affected.

[0162] Detection Example 2: Simultaneous Determination of Hg / As

[0163] Test sample: Soil

[0164] Since the content of As in soil is much higher than that of Hg, the existing atomic fluorescence spectrometer has not been able to simultaneously measure Hg and As in such samples. In this example, the device of the present invention is used to achieve simultaneous detection of Hg and As in the same sample.

[0165] Preparation of standard curve: Prepare a mixed standard solution containing 500ng / ml As and 5ng / ml Hg in advance. Take 0, 1, 2, 3, 4, 5ml of this standard solution in 50ml plastic quantitative bottles, add 5ml of 5% Vc-5% thiourea solution and 10ml of 50% HCl, dilute with water to the scale, and the Hg concentration in the obtained series of standard solutions is 0, 0.1, 0.2, 0.3, 0.4, 0.5ng / ml, and the As concentration is 0, 10, 20, 30, 40, 50ng / ml.

[0166] The double-channel method was selected, and the fluorescence signals of Hg and As in the blank and standard series solutions were simultaneously determined according to the above operation process, and standard curves of 0.1-0.5 ng / ml Hg and 10-50 ng / ml As of the mixed standard solution were prepared respectively. Fig. 8A is the peak curve of Hg / As, Figure 8B This is the standard curve of the mixed standard solution Hg and As (the signal of the standard curve is calculated based on the spectrum area, and the blank area has been subtracted).

[0167] Preparation and determination of test solution: 0.1-0.2g soil sample is placed in a 50ml plastic quantitative bottle, 5ml of 5% Vc-5% thiourea solution is added, 10ml of HCl with a concentration of 50% is added, and diluted to the scale with water. After shaking, the sample solution is used as the test solution. According to the operation process, the fluorescence signals of Hg and As in the sample solution are simultaneously determined. The concentrations of the corresponding elements are obtained according to their respective standard curves, and the contents of each element in the sample are calculated. The determination results are shown in Table 2.

[0168] Table 2. Simultaneous determination results of soil Hg / As

[0169]

[0170]

[0171] The data show that the method and device solve the difficulty of simultaneously determining Hg and As in soil. It can also be seen that the Hg concentrations in the six samples (standard samples) vary greatly. The results of the samples tested from top to bottom in Table 2 are consistent with the recommended values, indicating that the device of the present invention eliminates the serious memory effect of measuring Hg.

[0172] In this example, two elements coexist in the test solution. The delivery system only needs to complete the test solution delivery once, and the detection of the dual-channel detection system is also completed once. In this measurement operation, water is used as the carrier fluid without the need for hydrochloric acid. Only 100ml-250ml of NaBH4 solution is needed to participate in the reaction, and the time and cost of the entire testing process are greatly reduced.

[0173] Detection Example 3: Analysis of Pb

[0174] Test samples: Chemical reagents calcium chloride and calcium hydroxide

[0175] Preparation of lead standard curve: First prepare 100ng / ml lead standard solution, then take 0, 1, 2, 3, 4, 5ml of this standard solution in 50ml plastic quantitative bottles, add 10ml of 50% HCl solution and 5ml of 5% thiourea to each solution, dilute to the scale with water, the concentration of this standard series solution is 0, 2, 4, 6, 8, 10ng / ml Pb. After shaking well, measure the fluorescence signal of blank and standard series solutions according to the operation process, and prepare the standard curve (see Fig. 9B ), Fig. 9A The peak curve of Pb. During the operation, both the carrier gas and the auxiliary gas are Ar gas, and the flow rate of the carrier gas (outer tube) is controlled at 1000-1200 ml / min, and the flow rate of the auxiliary gas (inner tube) is controlled at 400-600 ml / min.

[0176] Preparation and determination of test solution: Weigh 0.2-0.3g of chemical reagent sample, transfer to a 50ml plastic quantitative bottle after dissolving, add 10ml of 50% HCl and 5ml of 5% thiourea, shake for 5-10min, dilute to scale with water, shake well and use the sample solution as the test solution to determine the fluorescence signal of the sample solution in the same way as the standard curve determination, obtain the concentration of Pb from the standard curve and convert it into the content in the sample. The determination results of Pb in chemical reagents are shown in Table 3.

[0177] Table 3. Determination results of Pb in calcium chloride and calcium hydroxide (ng / g)

[0178]

[0179] The original atomic fluorescence analysis required very strict control of acidity at 2% in the determination of Pb, otherwise no fluorescence signal could be detected. However, it is difficult for the test solution to meet this requirement after pretreatment. Moreover, the amount of hydrogen produced by the test solution with 2% acidity after the reduction reaction is small and difficult to ignite. In this example, while implementing external tube sampling, the carrier gas flow rate is increased, and the hydrogen flame is easy to ignite. Atomic fluorescence analysis of Pb in the test solution with 10% acidity can form a clear Pb peak curve (see Fig. 9A ), improve the detection sensitivity and realize the determination of Pb.

[0180] The above detection examples show that the atomic fluorescence analysis using the new atomic fluorescence analysis device can be successfully used for the determination of As, Hg, Pb and Cd in various samples. The detection limit and reproducibility data of mercury are listed in Table 4, indicating that the detection stability of the instrument of the present invention is good.

[0181] Table 4 Detection limit and reproducibility data of Hg

[0182]

Claims

1. A water-borne atomic fluorescence analysis device, comprising an infusion system and an instrument body, characterized in that: The instrument body includes a housing and a reactor, an atomizer, an optical circle, an excitation light source, a detector and a circuit and gas circuit integrated system assembled in the housing. The infusion system includes: A test solution bottle for containing a test solution, the test solution bottle being connected to the reactor through a sample injection tube; A reagent bottle for containing a reducing agent, the reagent bottle being connected to the reactor through a reagent inlet pipe; A water bottle for holding pure water, the water outlet of the water bottle is connected to the inlet of the sample tube and the inlet of the reagent tube through the water inlet pipe, and the water inlet is controlled by switching the water inlet pipe; and The infusion system does not contain a supporting device for infusing the carrier acid; The instrument body also includes a lamp position adjustment device for adjusting the excitation light source in the horizontal and vertical directions, and the adjustment knob is located on the side of the instrument body shell, including: Lamp holder, used for installing the lamp; A support base, on the upper surface of which a lamp holder is mounted; The horizontal adjustment mechanism is a gear combination structure, which is used to convert the rotation of the horizontal knob into the horizontal movement of the lamp holder on which the lamp is installed; The vertical adjustment mechanism includes a lead screw and a scissor-type structure connected to the lead screw through a lead screw nut assembly, and is used to convert the rotation of the lead screw into a change in the angle of the scissor-type structure, so as to drive the support seat supported on the scissor-type structure to move vertically up and down; A fixing frame, used for supporting the horizontal adjustment mechanism and the vertical adjustment mechanism; Elastic clamping pieces are fixed on both sides of the lamp holder, the lower ends of the two clamping pieces are fixed on the sides of the lamp holder, and the upper ends are bent outwards, forming an arc-shaped storage space with an upper opening, which is narrow at the top and wide at the bottom, for installing the lamp.

2. The water-borne atomic fluorescence analysis device according to claim 1, characterized in that: The sample inlet tube and the reagent inlet tube are both liquid inlet capillaries. The water bottle is changed into two water cups, one water cup is used for holding cleaning water, and the other water cup is used for holding carrier water. The liquid inlet capillaries are replaced and inserted in the two water cups.

3. The water-borne atomic fluorescence analysis device according to claim 2, characterized in that: The liquid inlet capillary is connected to the reactor through a peristaltic pump, and the peristaltic pump controls the delivery speed and infusion volume of the test solution, reducing agent, cleaning water and carrier water into the liquid inlet capillary.

4. The water-borne atomic fluorescence analysis device according to claim 1, characterized in that: The gas outlet pipeline of the reactor is connected to the outer pipe joint of the quartz furnace in the atomizer, and the inner pipe joint of the quartz furnace is connected to the argon gas pipeline serving as auxiliary gas.

5. The water-borne atomic fluorescence analysis device according to claim 1, characterized in that: The atomizer includes a furnace body support, a furnace core, a quartz furnace mounted inside the furnace core, and a furnace body cover mounted outside the furnace core, a ceramic cover plate, and an electric furnace wire. The furnace core and the furnace body cover are made of insulating and heat-resistant non-metallic materials, and the components are fixed without screws.

6. The water-borne atomic fluorescence analysis device according to claim 5, characterized in that: At least two slots are arranged on the upper end of the outer cover of the furnace body, and buckles are arranged on the side edges of the ceramic cover plate. The buckles are buckled with the slots to clamp the upper end of the outer cover of the furnace body with the ceramic cover plate.

7. The water-borne atomic fluorescence analysis device according to claim 6, characterized in that: The electric furnace wire is inserted and embedded between the ceramic cover plate and the quartz furnace tube mouth. A ceramic insulation layer instead of asbestos is arranged between the ceramic cover plate and the top surface of the furnace core. The ceramic insulation layer supports the electric furnace wire and positions it at the tube mouth of the quartz furnace.

8. The water-borne atomic fluorescence analysis device according to claim 5, characterized in that: A groove body and a step are arranged on the upper part of the furnace body support, and two slot holes are arranged on the side wall of the groove body; a protrusion is arranged on the lower part of the furnace core, and the protrusion is embedded in the groove body; the inner pipe joint and the outer pipe joint of the lower part of the quartz furnace are clamped in the slot hole and extend to the side; the quartz furnace is sleeved in the furnace core cavity, and the pipe mouth of the quartz furnace extends upward from the top surface of the furnace core; the furnace body cover is sleeved on the outer periphery of the furnace core, and the bottom of the furnace body cover is seated on the step of the furnace body support.

9. The water-borne atomic fluorescence analysis device according to claim 1, characterized in that: The optical circle includes a shell, one side of which is provided with mounting holes for mounting an excitation light source and a detector respectively, and a side cut groove is provided on the opposite side of the shell to the mounting hole for transmitting light emitted by the excitation light source.

10. The water-borne atomic fluorescence analysis device according to claim 9, characterized in that: The size of the side cut groove matches the adjustment range of the excitation light source, so that the characteristic spectrum emitted by the excitation light source will not be irradiated onto the housing of the optical circle.

11. The water-borne atomic fluorescence analysis device according to claim 9, characterized in that: Light-absorbing paper coated with black light-absorbing material is laid on the inner side of the atomic fluorescence instrument shell, and the side cut groove of the shell faces the light-absorbing paper.

12. The water-borne atomic fluorescence analysis device according to claim 1, characterized in that: The circuit and gas circuit integration system is an integral module, including a base plate, a switching power supply installed on the base plate, and a vertical frame type circuit and gas circuit integration module. The vertical frame type circuit and gas circuit integration module includes a power supply board, a control main board and a support board with fixed spacing in the vertical direction. The support board is installed with a gas control module and a gas pressure gauge. The control main board controls the flow of the gas channel of the gas control module; the power board modulates the power provided by the switching power supply into DC power of different ranges to supply the control main board and the gas control module.

13. The water-borne atomic fluorescence analysis device according to claim 12, characterized in that: The bottom plate and the bottom of the instrument body are nested with slide rails and grooves to achieve displacement.

14. The water-borne atomic fluorescence analysis device according to claim 1, characterized in that: A large display screen is arranged on the front panel of the instrument main body shell for displaying the desktop system content.

15. The water-borne atomic fluorescence analysis device according to any one of claims 1 to 14, characterized in that: The level adjustment mechanism comprises: A rack fixed to the bottom of the lamp holder; A spur gear is provided with an integrated sleeve and meshes with the rack; The spur gear adjusting shaft has a lower end rotatably mounted on a support beam, both ends of the support beam are fixed on a fixing frame, and an upper end is used to pass through the sleeve of the spur gear and is connected with the sleeve plane of the spur gear; Two vertically arranged and meshing bevel gears, the horizontal bevel gear is fixed on the spur gear adjustment shaft, and the vertical bevel gear is fixed on the end of the bevel gear adjustment shaft; The horizontal knob is connected to the bevel gear adjustment shaft through a coupling.

16. The water-borne atomic fluorescence analysis device according to claim 15, characterized in that: The support seat includes a horizontal plate and a first side plate vertically arranged on both sides of the horizontal plate. The spur gear is fixed in a groove opened at the bottom of the lamp tube holder. A sliding sleeve is fixed on each side of the groove at the bottom of the lamp tube holder. The sliding sleeve can be slidably inserted into a third sliding groove opened on the horizontal plate.

17. The water-borne atomic fluorescence analysis device according to claim 16, characterized in that: The fixing frame comprises a base, support plates fixed to both ends of the base and second side plates arranged on both sides of the base, and the second side plates are provided with mounting holes and first sliding grooves for supporting the vertical adjustment mechanism.

18. The water-borne atomic fluorescence analysis device according to claim 17, wherein the vertical adjustment mechanism comprises: A scissor-type structure formed by two supporting connecting rods, wherein two left corners of the scissor-type structure are respectively penetrated with a fixed rod, and two right corners are respectively penetrated with a sliding rod, and two ends of the fixed rod are respectively passed through the mounting holes of the second side plate and the first side plate for fixing; and two ends of the sliding rod are respectively slidably inserted into the second sliding groove of the second side plate and the first sliding groove of the first side plate; A lead screw and a lead screw nut assembly that is sleeved on the lead screw and threadedly connected to the lead screw, the lead screw head passes through the bearing, the support plate, the lead screw nut assembly in sequence and is fixed in the left bearing, the lead screw tail is connected to the vertical knob through a coupling, the upper end of the scissor-type structure formed by the two supporting connecting rods supports the horizontal plate of the support seat, and a sliding rod in the scissor-type structure passes through the lead screw nut and can be slidably sleeved in the second sliding groove of the second side plate.

19. An atomic fluorescence analysis method, using the water-carrier atomic fluorescence analysis device according to any one of claims 1 to 18, comprising the process of using the infusion system to use water as a carrier after sampling, and the atomization process of injecting the sample from the outer tube of the quartz furnace until the detection is completed.

20. The atomic fluorescence analysis method according to claim 19, characterized in that: The outer tube injection refers to passing the hydride and hydrogen mixed gas carried by the carrier gas from the reactor into the outer tube of the quartz furnace, passing the auxiliary gas into the inner tube of the quartz furnace, and controlling the flow rate.

21. The atomic fluorescence analysis method according to claim 20, characterized in that: Increase the carrier gas flow rate of the carrier mixed gas to 1000-1200 ml / min, and reduce the auxiliary gas flow rate to 400-600 ml / min or do not introduce auxiliary gas.

22. The atomic fluorescence analysis method according to claim 19, characterized in that: The sampling refers to the simultaneous introduction of a test solution with a certain acidity and a reducing agent with a certain concentration, and the water as a carrier refers to the use of pure water as a carrier to push the test solution and the reducing agent into the reactor.

23. The atomic fluorescence analysis method according to claim 22, characterized in that: The test solution is hydrochloric acid with a concentration range of 4%-10%.

24. The atomic fluorescence analysis method according to claim 22, characterized in that: The sampling time is 4-5 seconds, and the time from water flow to detection end is 8-10 seconds.

25. The atomic fluorescence analysis method according to claim 22, characterized in that: Use two cups to hold pure water. After sampling, the capillary tubes that transport the test solution and the reducing agent are swapped between the two cups of water. The sampling / delay / swapping / measurement times are 4-5 / 0 / 2-3 / 8-10 seconds, respectively. That is, the sampling time is 4-5 seconds, the delay is zero seconds, the swapping time is 2-3 seconds, and the time from carrying current to the end of detection is 8-10 seconds.

26. The atomic fluorescence analysis method according to any one of claims 19 to 25, characterized in that: The detection process also includes controlling the intermittent ignition of the hydrogen flame, and exciting the light source and the detector to work during the combustion time of the hydrogen flame.

Images