Semi-automatic positive-pressure solid-phase extraction device for large-volume sample injection and application thereof

Abstract

The invention provides a large-volume sample injection semi-automatic positive-pressure solid-phase extraction device and application thereof, and the large-volume sample injection semi-automatic positive-pressure solid-phase extraction device comprises a positive-pressure gas circuit part, a large-volume sample injection part, a leaching part, a solid-phase extraction part and a frame body part which are mounted in a layered manner. The positive pressure gas circuit part forms a detachable top cover, the large-volume sample injection part, the leaching part and the solid phase extraction part are connected through a liquid phase pipeline, a peristaltic pump and a liquid separation valve and are fixed on the frame body part, and the device selects eluent collection and waste liquid collection through a slide way. The positive pressure in the extraction process is guaranteed through the sealing hasp, the leacheate is switched through the three-way valve, the volume of the leacheate is controlled through the peristaltic pump, and semi-automation is achieved. During waste liquid collection, waste liquid automatically flows into a waste liquid bottle; when the extract liquor is collected, the centrifugal tube rack slides to be aligned with the solid-phase extraction column, and the extract liquor is collected into the centrifugal tube; the device can effectively ensure the sealing performance of a positive pressure system and the semi-automatic pipetting operation in the extraction process, and is simple in structure and quick to operate.

Description

TECHNICAL FIELD

[0001] The application discloses a semi-automatic positive pressure solid phase extraction device for large-volume sampling and application thereof, and belongs to the technical field of chromatographic analysis. BACKGROUND

[0002] Solid phase extraction is a kind of pretreatment technology combining liquid-solid extraction and column liquid chromatography. The adsorbent in the solid phase extraction column is used as the stationary phase, and the water sample is used as the mobile phase. When the sample flows through the adsorbent, the trace target object to be detected is retained, and the separation of the target object and the interference object can be realized by elution with a proper solvent, so that the interference of the sample matrix is reduced and the sensitivity of trace substance detection is improved. Compared with other pretreatment methods such as liquid-liquid extraction, solid phase extraction has the advantages of simple operation, less consumption of organic solvents, wide application range and the like, and the extraction materials are various, the selectivity is high, and common solid phase extraction columns include octadecylsilane chemically bonded silica (C18), hydrophilic-lipophilic balanced (HLB), mixed cation exchange (MCX), strong anion exchange (SAX) and the like, and are widely applied in the pretreatment of trace substances in drinking water, environmental water and wastewater.

[0003] The solid phase extraction process mainly includes four steps of column activation, sampling, elution and elution. The types and volumes of liquids removed in each step are different, and manual pipetting is low in efficiency; the solid phase extraction column should be sampled and extracted immediately after activation to avoid drying of the adsorbent and affect the adsorption efficiency; the flow rate of the sample should not be too large to ensure effective retention of the trace target object on the adsorbent; and the target object should be fully eluted before elution, so as to ensure the solid phase extraction efficiency. Although there are automatic solid phase extraction devices, they need to be controlled by a sensor program, which is high in cost and prone to failure. Once the program is running, it cannot be adjusted automatically when a fault occurs, and manual pause is often required, which is difficult to maintain.

[0004] In addition, the solid phase extraction column is greatly affected by the characteristics of the adsorbent, the filling process and the like, and the flow rate, and once the sample matrix is affected or the flow rate is not properly controlled, the column is easily blocked. When the demand for water sample is large, the time consumption is long, especially when the large-volume sampling is performed under negative pressure, the sampling flow rate of each solid phase extraction column cannot be accurately controlled, in addition, with the increase of the sampling volume, the volume of waste liquid is large, and the workload of waste liquid collection and transfer is obviously increased.

[0005] Therefore, it is urgent to design a semi-automatic positive pressure solid phase extraction device suitable for large-volume sampling, which can simultaneously realize the switching operation of pipetting and the control of the sampling flow rate, and has a low cost and a simple structure. SUMMARY

[0006] In view of the low pipetting efficiency, the inability to control the sample flow rate individually, and the large waste liquid treatment workload when large volume sample is injected in the prior solid phase extraction technology, the purpose of the present application is to provide a semi-automatic positive pressure solid phase extraction device for large volume injection and its application.

[0007] The technical solution adopted by the present application is as follows:

[0008] One of the technical solutions of the present application provides a semi-automatic positive pressure solid phase extraction device for large volume injection, which comprises a positive pressure gas path part, a large volume injection part, a washing part, a solid phase extraction part and a frame part.

[0009] The frame part comprises a solid phase extraction device base layer, a second layer frame, a third layer frame, a fourth layer frame and a fifth layer frame, which are fixed in series through a plurality of frame stand columns to ensure the stability and safety of the solid phase extraction device.

[0010] Further, the frame stand columns are preferably 6-8.

[0011] The positive pressure gas path part is a detachable gas path plate, which is provided with one positive pressure gas path air inlet pipe and a plurality of positive pressure air outlet holes.

[0012] Further, the four edges of the gas path plate are respectively provided with sealing clasp female buckles, and the corresponding positions of the fifth layer frame are respectively provided with sealing clasp male buckles.

[0013] Further, the positive pressure gas path air inlet pipe and each positive pressure air outlet hole are provided with a gas flow control valve for controlling the positive pressure.

[0014] Further, the gas supply device of the positive pressure gas path part is an inert bottled high-pressure gas or a vacuum pump.

[0015] The large-volume injection part and the elution part are special inverted mobile phase bottles; the inverted mobile phase bottles are fixed between the fourth layer frame and the fifth layer frame through the small mobile phase bottle fixing hole on the fourth layer frame and the large mobile phase bottle fixing hole on the fifth layer frame; the upper opening of the special inverted mobile phase bottle is an outwardly enlarged opening, and the diameter is consistent with the sealing ring of the gas path plate; the inverted mobile phase bottle of the large-volume injection part is a sample injection bottle, and the lower opening is a single-hole threaded mobile phase bottle cap; the single hole of the single-hole threaded mobile phase bottle cap is connected with a liquid tube, and the liquid tube is connected with the solid phase extraction part through a three-way valve A; the inverted mobile phase bottle of the elution part is an elution liquid bottle, which is divided into an aqueous elution liquid bottle A and an organic phase elution liquid bottle B, and the lower opening is a single-hole threaded mobile phase bottle cap; the single hole of the threaded mobile phase bottle cap is connected with an elution liquid tube, and the elution liquid tubes of the elution liquid bottle A and the elution liquid bottle B are connected with the inlet end of a peristaltic pump through a three-way valve B; the outlet end of the peristaltic pump is connected with the third port of the three-way valve A through an N-way valve; the value of N of the N-way valve is the number of sample injection bottles plus 1; the inlet of the N-way valve is provided with a shut-off valve.

[0016] Further, the elution liquid bottle cap can also be provided as a double-hole bottle cap, wherein the hole not connected with the elution liquid tube is connected with an elution liquid replacement tube, and the port of the elution liquid replacement tube is provided with a shut-off valve.

[0017] Further, the sample injection bottle of the large-volume injection part is a tetrafluoroethylene bottle, which is shaped like an inverted mobile phase bottle for liquid chromatography, and the volume is preferably 500 mL to 1 L, and the number is 6 to 12.

[0018] Further, the elution liquid bottle of the elution part is a tetrafluoroethylene bottle, which is shaped like an inverted mobile phase bottle for liquid chromatography, and the volume is preferably 500 mL to 1 L, and the number is 2 to 4.

[0019] Further, the number of sample injection bottles, solid phase extraction columns and centrifuge tubes is equal.

[0020] The solid phase extraction part is arranged from top to bottom as a solid phase extraction column, a centrifuge tube and a waste liquid collection part, the waste liquid collection part includes a waste liquid tank, a waste liquid discharge pipe and a waste liquid bottle; the solid phase extraction column is placed on the solid phase extraction column fixing hole provided on the third layer frame, and an adapter is installed on the upper opening of the solid phase extraction column and connected with the liquid tube of the sample injection bottle; the centrifuge tube is placed on the centrifuge tube fixing hole provided on the second layer frame, and when the target elution is performed, the bracket plate where the centrifuge tube fixing hole is located is slidably fixed to the front half part of the solid phase extraction device through the clamping groove, and is aligned with the lower opening of the overhanging solid phase extraction column to collect the target elution liquid; the waste liquid tank is placed in the front half part of the solid phase extraction device, and is connected with the waste liquid bottle through the waste liquid discharge pipe, and is used to collect the waste liquid in the activation, sample loading and elution processes.

[0021] Further, the solid phase extraction device does not require direct plug-in power supply facilities, and is suitable for both laboratory operation and installation on a flow detection vehicle for rapid processing of on-site samples.

[0022] Further, the solid phase extraction device individualizes and regulates the flow rate of the solid phase extraction column through an independent air flow control valve, realizes liquid transfer switching and volume control through a three-way valve, an N-way valve and a peristaltic pump, and designs a slide for the centrifuge tube rack to facilitate waste liquid collection and eluent collection operation.

[0023] The second technical solution of the present application provides a use method of a semi-automatic solid phase extraction device for large-volume sample injection, comprising the following steps:

[0024] In the initial state, the gas path plate is covered on the top of the solid phase extraction device, the sealing ring is aligned with the upper opening of the large-volume sample injection bottle and the eluent bottle, and the four buckles are locked; the control valve switches of all gas plates are closed; the outlet of the solid phase extraction column is aligned with the waste liquid tank; the eluent bottle A is filled with water phase, and the eluent bottle B is filled with organic phase;

[0025] S1. Open the three-way valve B at the outlet of the eluent bottle A, connect the three-way valve A at the outlet of the large-volume sample injection bottle with the N-way valve, and start the peristaltic pump to activate the solid phase extraction column with appropriate volume of water;

[0026] S2. Adjust the switch of the three-way valve B to the eluent bottle B, start the peristaltic pump to activate the solid phase extraction column with appropriate volume of organic phase, and close the three-way valve B;

[0027] S3. Open the three-way valve A connected with the large-volume sample injection bottle and the solid phase extraction column, and the gas flow control valve of the corresponding gas outlet hole of the gas path, adjust the positive pressure according to the flow rate of the solid phase extraction column, and the flow rate is <5 mL / min. After the sample injection is completed, the gas path plate is depressurized, the corresponding positive pressure gas path control valve of the eluent bottle A is closed, and the three-way valve A is closed;

[0028] S4. Open the three-way valve B at the outlet of the eluent bottle A, and connect the three-way valve A at the outlet of the large-volume sample injection bottle with the N-way valve, start the peristaltic pump to elute the solid phase extraction column with appropriate volume of eluent A, adjust the switch of the corresponding gas path control valve of the eluent bottle according to the liquid flow rate, control the elution flow rate by positive pressure; after the elution is completed, the solid phase extraction column is dried by positive pressure, then the gas path plate is depressurized, and the corresponding positive pressure gas path control valve of the eluent bottle A is closed;

[0029] S5. In the above 4 steps, the waste liquid flowing out of the solid phase extraction column is collected through the waste liquid tank and flows into the waste liquid bottle;

[0030] S6. Pull the centrifuge tube rack along the slide to the clamping position of the front half of the solid phase extraction device, and align the centrifuge tube with the solid phase extraction column outlet. Adjust the switch of three-way valve B to the eluent bottle B, start the peristaltic pump, and elute the solid phase extraction column with an appropriate volume of organic phase. According to the liquid flow rate, adjust the switch of the corresponding gas path control valve, and control the elution flow rate under positive pressure. After elution, release the pressure of the gas path plate, close the positive pressure gas path control valve corresponding to the eluent bottle B, and close three-way valve A.

[0031] Further, the aqueous phase is deionized water, the organic phase is methanol, ethyl acetate or methanol: water (1:1, v / v) solution, preferably methanol.

[0032] The third technical solution of the application provides an application of a semi-automatic solid phase extraction device for large-volume sample injection, which is used for determination of the content of triclocarban and triclosan in drinking water samples.

[0033] By using the operation device, the application has the following beneficial effects:

[0034] 1. Independent gas positive pressure control valves are set for each sample, so that the flow rates of multiple sample injections can be individually adjusted when the adsorption and separation resistance of the solid phase extraction column is uneven, and the extraction of trace target substances in water samples can be carried out at the set appropriate flow rate.

[0035] 2. The three-way and six-way valves are used to connect and switch the liquid phase pipelines for different samples, water and organic phases used in different steps of the solid phase extraction process, so that semi-automatic pipetting operations are realized in the four steps of activation, sample loading, elution and elution.

[0036] 3. The positive pressure flow rate control is combined with the quantitative pipetting of the peristaltic pump, so that the user can select sample injection or pipetting operation according to the combination of solid phase extraction steps.

[0037] 4. The waste liquid flowing out of the solid phase extraction column directly flows into the waste liquid bottle through the waste liquid tank, effectively avoiding the risk of frequent waste liquid pouring or even backflow into the vacuum pump caused by a large amount of waste liquid generated by negative pressure large-volume sample injection.

[0038] 5. The centrifuge tube rack for target substance collection is designed and installed by using a slide, so that the centrifuge tube rack for target substance collection is designed and installed by using a slide, so that the centrifuge tube rack for target substance collection is designed and installed by using a slide. BRIEF DESCRIPTION OF DRAWINGS

[0039] (6 sample bottles are taken as an example)

[0040] Figure 1 Semi-automatic positive pressure solid phase extraction device for large-volume sample injection - flowchart;

[0041] Figure 2 Semi-automatic positive pressure solid phase extraction device for large-volume sample injection - principle schematic diagram;

[0042] Figure 3 Semi-automatic positive pressure solid phase extraction device for large volume injection - front view schematic diagram;

[0043] Figure 4 Semi-automatic positive pressure solid phase extraction device for large volume injection - back view schematic diagram;

[0044] Figure 5 Semi-automatic positive pressure solid phase extraction device for large volume injection - 2nd layer top view schematic diagram - waste liquid collection state;

[0045] Figure 6 Semi-automatic positive pressure solid phase extraction device for large volume injection - 2nd layer top view schematic diagram - target elution state;

[0046] Figure 7 Semi-automatic positive pressure solid phase extraction device for large volume injection - 3rd layer top view schematic diagram;

[0047] Figure 8 Semi-automatic positive pressure solid phase extraction device for large volume injection - 4th layer top view schematic diagram;

[0048] Figure 9 Semi-automatic positive pressure solid phase extraction device for large volume injection - 5th layer top view schematic diagram;

[0049] Figure 10 Semi-automatic positive pressure solid phase extraction device for large volume injection - 5th layer bottom view schematic diagram;

[0050] Figure 11 Semi-automatic positive pressure solid phase extraction device for large volume injection - gas path plate top view schematic diagram;

[0051] Figure 12 Semi-automatic positive pressure solid phase extraction device for large volume injection - gas path plate bottom view schematic diagram;

[0052] Wherein: L1 base layer; L2 2nd layer frame; L3 3rd layer frame; L4 4th layer frame; L5 5th layer frame; L6 top layer;

[0053] C1 frame column;

[0054] 11 waste liquid bottle; 12 waste liquid discharge pipe; 13 waste liquid tank;

[0055] 21 slide slot; 22 centrifugal tube; 23 centrifugal tube fixing hole;

[0056] 31 solid phase extraction column; 32 adapter; 33 peristaltic pump; 34A three-way valve A, 34B three-way valve B; 35 seven-way valve; 36 solid phase extraction column fixing hole;

[0057] 41 single-hole threaded mobile phase bottle cap; 42 inverted mobile phase bottle; 43 small mobile phase bottle fixing hole;

[0058] 51 Sealing snap fastener; 52 Large flow phase bottle fixing hole;

[0059] 61 Gas circuit board support column; 62 Sealing snap fastener; 63 Gas circuit board; 64 Gas flow control valve; 65 Positive pressure gas inlet pipe; 66 Positive pressure gas outlet; 67 Sealing ring.

[0060] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used to explain the invention but do not constitute a limitation thereof. Detailed Implementation

[0061] To make the design purpose, technical solution and application effect of the present invention clearer and more complete, the following is a sample pretreatment implementation plan for determining triclocarban and triclosan in drinking water samples using the present invention.

[0062] Therefore, the detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the practical application of the invention without inventive effort are within the scope of protection of this invention. There are no particular restrictions on the source of all raw materials used in this invention; they can be purchased commercially or prepared according to conventional methods known to those skilled in the art.

[0063] The reference numerals and letters appearing in this embodiment, if already defined in the accompanying drawings and descriptions, will not be further defined or explained in the subsequent drawings. In the description of the embodiments of this invention, unless otherwise expressly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly, encompassing fixed connections, detachable connections, or integral connections; they can be direct connections, indirect connections via an intermediate medium (such as an adapter), or internal connections between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention.

[0064] Example 1: A semi-automatic solid-phase extraction device with large-volume sample introduction

[0065] Refer to the appendix to this invention specification. Figure 1 -Appendix Figure 11 The present invention provides a semi-automatic solid-phase extraction device for large-volume sample introduction, such as... Figures 2-4, the frame body part includes a base layer L1, a second layer frame body L2, a third layer frame body L3, a fourth layer frame body L4, a fifth layer frame body L5 and a top layer L6. The base layer L1, the second layer frame body L2, the third layer frame body L3, the fourth layer frame body L4 and the fifth layer frame body L5 are sequentially connected from bottom to top through the frame body column C1; the frame body column C1 is provided with six (provided in the width direction, three on each side) and passes through each layer through a small hole to ensure the stability of the frame body.

[0066] As Figure 5 , the base layer L1 of the device is provided with a waste liquid tank 13, which is connected to the waste liquid bottle 11 through the waste liquid discharge pipe 12. The length of the waste liquid tank 13 is slightly smaller than the length of the base layer L1, which can be installed between the frame body columns C1 on both sides, and the width of the waste liquid tank 13 is less than half the width of the base layer L1, which is placed on one side of the base layer L1.

[0067] As Figures 5-6 , the second layer frame body L2 is provided with two slide slots 21 in the width direction, and the second layer frame body L2 is divided into three movable parts through the slide slots 21. That is, the second layer frame body L2 is fixedly connected with the frame body columns C1 on both sides, and the middle part can move back and forth in the width direction through the slide slots 21.

[0068] As Figure 7 , the third layer frame body L3 has a width of half the width of the second layer frame body L2 and is arranged directly above the waste liquid tank 13, and is connected with two frame body columns C1 on each side.

[0069] As Figures 8-10 , the fourth layer frame body L4 and the fifth layer frame body L5 are each provided with eight (arranged in 4*2) circular holes, wherein the circular holes provided on the fourth layer frame body L4 are small mobile phase bottle fixing holes 43, and the circular holes provided on the fifth layer frame body L5 are large mobile phase bottle fixing holes 52. The small mobile phase bottle fixing holes 43 and the large mobile phase bottle fixing holes 52 arranged above and below correspond to each other (the center line of the circle is parallel to the length direction of the frame body column C1), and each pair of fixing holes is used to fix a special inverted mobile phase bottle 42, and the upper bottle bottom of the special inverted mobile phase bottle 42 is not sealed.

[0070] As Figures 11-12 , the top layer L6 includes a gas path board support column 61, a sealing buckle female buckle 62, a gas path board 63, a gas flow control valve 64, a positive pressure gas path inlet pipe 65, a positive pressure gas outlet hole 66 and a sealing ring 67.

[0071] The bottom of the gas path plate support column 61 is suspended, and the top is fixed on the gas path plate. When the gas path plate is removed, the bottom of the gas path plate support column 61 contacts the desktop, which can protect the sealing ring and the gas outlet hole from being contaminated. The sealing buckle female buckle 62 is provided with four, which are respectively arranged on the four edges of the gas path plate 63, and correspond to the sealing buckle male buckle 51 of the fifth layer. The gas flow control valve 64 is arranged beside each positive pressure gas outlet hole 66, and each gas flow control valve 64 is responsible for controlling the opening and closing of the corresponding positive pressure gas outlet hole 66. The positive pressure gas path inlet pipe 65 is respectively communicated with each positive pressure gas outlet hole 66 in the gas path plate, and the flow switch is controlled through the corresponding gas flow control valve 64. The positive pressure gas path inlet pipe 65 is connected with the inert gas cylinder or vacuum pump. The sealing ring 67 corresponds to the bottle opening edge of the upper bottle bottom of the special inverted flow phase bottle 42, so that the special inverted flow phase bottle 42 can be in a sealed state. The above-mentioned gas path plate is a common gas distribution and transmission device in the prior art, and its principle and structure do not belong to the core content of the present application, so it is not described in detail.

[0072] The special inverted flow phase bottle 42 contains six large volume sample bottles and two eluent bottles (including eluent bottle A and eluent bottle B). The outlet liquid pipes of the two eluent bottles are connected with the seven-way valve through the three-way valve and the peristaltic pump Figure 2 The six outlet liquid pipes of the six large volume sample bottles are respectively connected with the six large volume sample bottles through the three-way valve, and then connected with the six solid phase extraction columns 31 (HLB, 200mg, 6mL) through the six-way valve. The bottom end of the solid phase extraction column 31 is respectively placed in the centrifugal tube 22.

[0073] The special inverted flow phase bottle 42 is fixed on the fourth layer frame L4 and the fifth layer frame L5, the solid phase extraction column 31 is fixed on the solid phase extraction column fixing hole 36, and the centrifugal tube 22 is fixed on the centrifugal tube fixing hole 23.

[0074] Example 2: a method for using a large volume sample semi-automatic solid phase extraction device

[0075] The use method of the embodiment is specifically as follows Figure 1 .

[0076] Before use, check that the waste liquid tank 13 is located below the solid phase extraction column 31.

[0077] In the eluent bottle A, add 200 mL of freshly prepared deionized water, and in the eluent bottle B, add 200 mL of chromatographically pure methanol; rotate the three-way valve B to eluent B, open the seven-way valve, rotate the six three-way valves A to the eluent pipe connection, start the peristaltic pump, and observe 6 mL of methanol flowing into the solid phase extraction column body; close the peristaltic pump, close the three-way valve B, and rotate the three-way valve A to connect to the large volume sample bottle (a specially designed inverted mobile phase bottle 42) to prevent negative pressure in the liquid pipe from affecting the activation of the solid phase extraction column 31.

[0078] After the methanol flows out of the solid phase extraction column 31, rotate the three-way valve B to eluent A, open the seven-way valve, rotate the six three-way valves A to the eluent pipe opening, start the peristaltic pump, and observe 6 mL of deionized water flowing into the solid phase extraction column 31 body; close the peristaltic pump, close the three-way valve B, and rotate the three-way valve A to connect to the large volume sample bottle to prevent negative pressure in the liquid pipe from affecting the activation of the solid phase extraction column 31.

[0079] After the deionized water flows out of the solid phase extraction column 31, collect 6 samples of network terminal water samples according to the GB / T 5750.2-2023 Standard Test Methods for Drinking Water Sample Collection and Preservation requirements, and add 1 L of each sample after 3000 rpm centrifugation to the six large volume sample bottles (specially designed inverted mobile phase bottles 42). Cover the gas path plate 63 on the 5th layer of the rack body L5, align the sealing ring 67, and lock the sealing buckle mother buckle 62 and the sealing buckle child buckle 51.

[0080] Rotate the six three-way valves 34A to the large volume sample tube (connected to the large volume sample bottle). Open the gas inlet valve of the gas path plate 63, gently rotate each gas flow control valve 64, and adjust the positive pressure to about 3 mL / min for each solid phase extraction column according to the pressure difference in each solid phase extraction column 31 and the liquid pipe.

[0081] After the water sample is extracted and flows out of the solid phase extraction column, adjust the gas path plate pressure relief, rotate the three-way valve 34B to eluent A, open the seven-way valve, rotate the six three-way valves 34A to the eluent pipe opening, start the peristaltic pump, and observe 6 mL of deionized water flowing into the solid phase extraction column body; close the peristaltic pump, and close the three-way valve 34B.

[0082] Rotate the three-way valve 34A to the large volume sample tube, adjust the gas path control valve of the gas path plate to the positive pressure state, and after the deionized water flows out of the solid phase extraction column, blow dry the solid phase extraction column for 2-3 min, and adjust the gas path plate pressure relief.

[0083] Rotate the three-way valve 34B to the eluent B, open the seven-way valve, rotate the six three-way valves 34A to the eluent pipe open, start the peristaltic pump, and observe 3 mL of methanol flowing into the solid-phase extraction column. Close the peristaltic pump and close the three-way valve 34B. Slide the centrifuge tube holder to the collection position and ensure that the centrifuge tube is aligned with the solid-phase extraction tube outlet.

[0084] Rotate the three-way valve 34A to the large-volume sample inlet pipe, adjust the gas path control valve of the gas path board to a low positive pressure state, and observe the methanol flowing out at a single drop and slowly dripping. When 3 mL of methanol is completely collected into the centrifuge tube, the methanol is redissolved to 1 mL after nitrogen blowing for machine determination.

[0085] Release the pressure of the gas path board 63, open the sealing buckle female buckle 62 and the sealing buckle male buckle 51, remove the gas path board 63, rinse the large-volume sample bottle with deionized water, recover the organic solution in the eluent B, and clean the waste liquid tank 13. The waste liquid is to be harmlessly treated.

[0086] Test results:

[0087] The sample extracted according to the above operation steps is nitrogen blown to near dryness at 30°C, redissolved with 1.0 mL of methanol, filtered through a 0.45 μm filter membrane, and then determined on the machine. The detection values of the target pollutants in the 6 tube network end water samples are all below the method detection limit. The specific detection limits of the triclocarban and triclosan are 5 ng / L and 15 ng / L, respectively.

[0088] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. Those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described herein to other embodiments without having to go through creative labor. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A semi-automated positive pressure solid phase extraction device for large volume injection, characterized in that, The device comprises a positive pressure gas path part, a large volume sample injection part, a washing part, a solid phase extraction part and a frame part; The frame part comprises a solid phase extraction device base layer (L1), a second layer frame (L2), a third layer frame (L3), a fourth layer frame (L4) and a fifth layer frame (L5), which are fixed in series through a plurality of frame columns (C1); the positive pressure gas path part is arranged at the top of the frame part, and the large volume sample injection part, the washing part and the solid phase extraction part are arranged inside the frame part and supported and fixed by the frame part; The positive pressure gas path part is a detachable gas path plate (63), which is provided with one positive pressure gas path air inlet pipe (65) and a plurality of positive pressure air outlet holes (66), and a gas path pipe connecting the positive pressure gas path air inlet pipe (65) and the positive pressure air outlet holes (66) is arranged in the gas path plate (63); the periphery of the positive pressure air outlet hole (66) is designed with a sealing ring (67) for abutting the upper opening of an inverted mobile phase bottle (42); The large volume sample injection part and the washing part are both provided with a plurality of inverted mobile phase bottles (42); the inverted mobile phase bottles (42) are fixed between the fourth layer frame (L4) and the fifth layer frame (L5); the upper opening of the inverted mobile phase bottle (42) is an outwardly enlarged opening, and the caliber is consistent with the sealing ring (67) of the gas path plate (63); the inverted mobile phase bottle (42) is a sample injection bottle, and the lower opening is a single-hole threaded mobile phase bottle cap (41); the single hole of the single-hole threaded mobile phase bottle cap (41) of the large volume sample injection part is connected with a liquid pipe, the liquid pipe is connected with the solid phase extraction part through a three-way valve A (34A); the inverted mobile phase bottle (42) of the washing part is a washing liquid bottle, which is divided into a water phase washing liquid bottle A and an organic phase washing liquid bottle B, and the lower opening is a single-hole threaded mobile phase bottle cap (41); the single hole of the single-hole threaded mobile phase bottle cap (41) of the washing part is connected with a washing liquid pipe, and the washing liquid pipes of the washing liquid bottle A and the washing liquid bottle B are connected with the inlet end of a peristaltic pump through a three-way valve B (34B); the output end of the peristaltic pump is connected with the third port of the three-way valve A (34A) through an N-way valve; the value of N of the N-way valve is the number of sample injection bottles + 1; the inlet of the N-way valve is provided with a closing valve; The solid phase extraction part is arranged from top to bottom as a solid phase extraction column (31), a centrifugal tube (22) and a waste liquid collection part, the waste liquid collection part includes a waste liquid tank (13), a waste liquid discharge pipe (12) and a waste liquid bottle (11); the solid phase extraction column (31) is placed on the solid phase extraction column (31) fixing hole arranged on the third layer frame body (L3), the upper opening of the solid phase extraction column (31) is provided with an adapter connected with the liquid pipe of the sample bottle; the centrifugal tube (22) is placed on the centrifugal tube (22) fixing hole arranged on the second layer frame body (L2), when the target is eluted, the centrifugal tube (22) fixing hole is slidably fixed to the front half part of the solid phase extraction device through the slide clamping groove (21), the bracket plate is aligned with the lower opening of the suspended solid phase extraction column (31), and the target eluent is collected; the waste liquid tank (13) is placed in the front half part of the solid phase extraction device, connected with the waste liquid bottle (11) through the waste liquid discharge pipe (12), and used for collecting the waste liquid in the activation, sample loading and elution processes.

2. The semi-automatic positive pressure solid phase extraction device for large volume injection according to claim 1, characterized in that, The frame body column (C1) is 6-8.

3. The semi-automatic positive pressure solid phase extraction device for large volume injection according to claim 1, characterized in that, The four edges of the gas path plate (63) are respectively provided with sealing buckle female fasteners (62), the corresponding positions of the fifth layer frame body (L5) are respectively provided with sealing buckle male fasteners (51), the sealing buckle female fasteners (62) and the sealing buckle male fasteners (51) are matched with each other, so that the gas path plate (63) is fixedly connected with the fifth layer frame body (L5).

4. The semi-automatic positive pressure solid phase extraction device for large volume injection according to claim 1, characterized in that, The positive pressure gas path inlet pipe (65) and each positive pressure outlet hole (66) are provided with a gas flow control valve (64) for controlling the positive pressure.

5. The semi-automatic positive pressure solid phase extraction device for large volume injection according to claim 1, characterized in that, The gas supply device of the positive pressure gas path part is an inert bottled high-pressure gas or a vacuum pump.

6. The semi-automatic positive pressure solid phase extraction device for large volume injection according to claim 1, characterized in that, The sample bottles of the large-volume sample injection part are tetrafluoroethylene bottles, and the number is 6-12; the elution liquid bottles of the elution part are tetrafluoroethylene bottles, and the number is 2-4.

7. The semi-automatic positive pressure solid phase extraction device for large volume injection according to claim 1, characterized in that, The number of the sample bottles, the solid phase extraction columns and the centrifugal tubes is equal.

8. The semi-automatic positive pressure solid phase extraction device for large volume injection according to claim 1, characterized in that, The cap of the elution liquid bottle is provided with a double-hole threaded mobile phase bottle cap, the hole not connected with the elution liquid pipe is connected with an elution liquid changing pipe, and the port of the elution liquid changing pipe is provided with a closing valve.

9. A method of using a semi-automated solid phase extraction device for large volume injection, characterized by, The use method of the large-volume sample semi-automatic positive pressure solid phase extraction device according to any one of claims 1-8 comprises the following steps: In the initial state, the gas path plate (63) is covered on the top of the solid phase extraction device, the sealing ring (67) is aligned with the upper openings of the sample bottles and the elution liquid bottles, and the four buckles are locked; the control valve switches of all the gas plates are closed; the outlet of the solid phase extraction column (31) is aligned with the waste liquid tank (13); the elution liquid bottle A is filled with an aqueous phase, and the elution liquid bottle B is filled with an organic phase; S1. opening the three-way valve B at the outlet of the elution liquid bottle A, connecting the three-way valve A (34A) at the outlet of the large-volume sample bottle with the N-way valve, starting the peristaltic pump, and activating the solid phase extraction column (31) with a proper amount of water; S2. adjusting the switch of the three-way valve B to the elution liquid bottle B, starting the peristaltic pump, activating the solid phase extraction column (31) with the organic phase, and closing the three-way valve B; S3. Open the three-way valve A (34A) connecting the large volume sample injection bottle and the solid phase extraction column (31) and the corresponding gas flow control valve of the gas outlet hole, adjust the positive pressure according to the flow rate of the solid phase extraction column (31), the flow rate <5 mL / min, the injection is completed, the gas path board (63) is depressurized and the corresponding positive pressure gas path control valve of the eluent bottle A is closed, the three-way valve A (34A) is closed; S4. Open the three-way valve B of the eluent bottle A outlet and the three-way valve A (34A) connected with the large volume sample injection bottle outlet and N-way valve, start the peristaltic pump, elute the solid phase extraction column (31) with eluent A, adjust the opening and closing of the corresponding gas path control valve of the eluent bottle, control the elution flow rate by positive pressure; After elution, the solid phase extraction column (31) is dried by positive pressure, and the gas path board (63) is depressurized and the corresponding positive pressure gas path control valve of the eluent bottle A is closed; S5. The waste liquid flowing out of the solid phase extraction column (31) in the above S4 step is collected by the waste liquid tank (13) and flows into the waste liquid bottle (11); S6. The centrifugal tube (22) frame is pulled to the clamping position of the front half of the solid phase extraction device, the centrifugal tube (22) is aligned with the outlet of the solid phase extraction column (31); adjust the opening and closing of the three-way valve B to the eluent bottle B, start the peristaltic pump, elute the solid phase extraction column (31) with appropriate volume of organic phase; According to the liquid flow rate, adjust the opening and closing of the corresponding gas path control valve of the eluent bottle, control the elution flow rate by positive pressure; After elution, the gas path board (63) is depressurized and the corresponding positive pressure gas path control valve of the eluent bottle B is closed, and the three-way valve A (34A) is closed.

10. Use of a semi-automatic solid phase extraction device for large volume injection, characterized in that, The device is used for the determination of the content of triclocarban and triclosan in drinking water samples.

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