阅读说明：本技术 一种三级色谱快速测定固体样品中有机化合物的方法 (Method for rapidly determining organic compounds in solid sample by three-stage chromatography ) 是由 郭治安 于 2019-08-05 设计创作，主要内容包括：本发明公开了一种三级色谱快速测定固体样品中有机化合物的方法,其包括一级色谱,样品的高温高压色谱提取；二级色谱,样品的色谱净化；三级色谱,样品的色谱分离与分析三个步骤。本发明创建了集提取、净化、分离测定于一体的三级色谱测试法,一次完成样品处理和测试的全过程,省去了样品转移、浓缩等环节,分析时间大大减少,且不需要高效快速溶剂萃取仪和其它大型设备,成本低,另外样品量和提取溶剂用量小,提高了样品利用率、降低了环境污染。(The invention discloses a method for rapidly determining organic compounds in a solid sample by three-stage chromatography, which comprises the steps of primary chromatography, high-temperature high-pressure chromatographic extraction of the sample; secondary chromatography, chromatographic purification of the sample; three-stage chromatography, and chromatographic separation and analysis of a sample. The invention creates a three-stage chromatographic test method integrating extraction, purification, separation and measurement, finishes the whole process of sample treatment and test at one time, saves the links of sample transfer, concentration and the like, greatly reduces the analysis time, does not need a high-efficiency rapid solvent extraction instrument and other large-scale equipment, has low cost, and improves the utilization rate of the sample and reduces the environmental pollution because the sample amount and the extraction solvent amount are small.)

1. A method for rapid determination of organic compounds in a solid sample by three-stage chromatography, comprising the steps of:

(1) primary chromatography: performing high-temperature high-pressure chromatographic extraction on a sample;

(2) secondary chromatography: chromatographic purification of the sample;

(3) and (3) tertiary chromatography: chromatographic separation and analysis of the sample.

2. The method for rapid determination of organic compounds in a solid sample by three-stage chromatography according to claim 1, wherein in the step (1), the high temperature high pressure chromatography extraction of the sample comprises the following steps:

(a) sampling: preparing a solid sample to be measured into particles, weighing about 0.1g of the solid sample to fill an extraction chromatographic column, connecting the extraction chromatographic column in series to a quantitative ring position of a liquid chromatogram six-way valve, and rotating the liquid chromatogram six-way valve to a sample loading position;

(b) wet sample: injecting a solvent from a sample injection port of the liquid chromatogram six-way valve by using a micro-injector, wherein the dosage of the solvent is based on the immersed sample;

(c) static extraction: switching on a switch valve at the inlet of a chromatographic column of the liquid chromatography six-way valve, closing the switch valve, sequentially switching on a purification chromatographic column and an analysis chromatographic column behind the switch valve, setting a solvent gradient and flow rate program of the liquid chromatography, rotating the liquid chromatography six-way valve to a sample introduction position, keeping the flow rate of a pump to be zero when the pressure reaches a specified pressure, and simultaneously heating the extraction chromatographic column;

(d) dynamic extraction: and (c) after the step (c) is kept for a period of time, opening the switch valve, and simultaneously increasing the flow rate in the flow rate program to perform dynamic extraction, wherein the process is still kept for a period of time.

3. The method for three-stage chromatographic rapid determination of organic compounds in solid samples as claimed in claim 2, wherein the step of purifying, separating and analyzing the samples comprises rotating the liquid chromatographic six-way valve to the loading position after the step (d) of dynamic extraction is completed, and performing isocratic elution or gradient elution separation on the samples in the analytical chromatographic column according to the separation condition.

4. The method for rapid determination of organic compounds in a solid sample by three-stage chromatography according to claim 3, wherein the mobile phase is selected from acetonitrile and water when gradient elution is used for separating the sample.

Technical Field

The invention belongs to the field of chemical substance detection, and particularly relates to a method for rapidly determining organic compounds in a solid sample by three-stage chromatography.

Background

The pretreatment method for analyzing and measuring the effective components and harmful components of the solid substances comprises the modes of extraction, concentration, rough separation, purification and concentration, and finally adopts high performance liquid chromatography or liquid chromatography-mass spectrometry combined analysis.

For example, in the sample treatment of 'determination of polycyclic aromatic hydrocarbons of soil and sediments-high performance liquid chromatography HJ 784-2016', 'determination of semi-volatile organic compounds of soil and sediments-gas chromatography-mass spectrometry HJ 834-2017', when the classical method is used for extraction, Soxhlet extraction of 10 g of soil sample by 100ml of organic solvent takes 18 hours; concentrating the solvent to 3ml by a nitrogen blowing method, purifying by chromatography, repeatedly adding acetonitrile for nitrogen blowing concentration to ensure that the original solvent is completely replaced by acetonitrile and concentrated to less than 1ml, transferring to a bottle with the capacity of 1ml, fixing the volume to the scale by using the acetonitrile, sucking 10ul (one percent of 1 ml) for chromatographic test, and having extremely low sample utilization rate; the sample treatment time is about 3 working days, about 200ml of organic solvent is used for sample treatment, the organic solvent is completely evaporated into the environment, and the treatment error of the sample concentrated by repeated nitrogen blowing in a 1ml volumetric flask in a container is more than 10%.

The new high-temperature high-pressure extraction can replace a Soxhlet extraction step, so that the original extraction time of 18 hours is shortened to 0.5 hour, but the time of other processing steps is not shortened, the link of error introduction is not eliminated, and a set of high-efficiency rapid solvent extraction instrument with the price equivalent to that of a high-efficiency liquid chromatograph is added, so that the cost is increased.

Disclosure of Invention

In order to solve the problems, the invention provides a method for rapidly determining organic compounds in a solid sample by three-stage chromatography, which comprises the following steps:

(1) primary chromatography: performing high-temperature high-pressure chromatographic extraction on a sample;

(2) secondary chromatography: chromatographic purification of the sample;

(3) and (3) tertiary chromatography: chromatographic separation and analysis of the sample.

In the scheme, the high-temperature high-pressure chromatographic extraction analysis of the sample comprises the following steps:

(a) sampling: preparing a solid sample to be measured into particles of 60-80 meshes, weighing 0.1g, selecting a proper extraction chromatographic column to fill the solid sample, connecting the extraction chromatographic column in series to a quantitative ring (loop) position of a liquid chromatography six-way valve, and rotating the liquid chromatography six-way valve to a sample loading (load) position;

(b) wet sample: injecting a solvent from a sample injection port of the liquid chromatogram six-way valve by using a micro-injector, wherein the dosage of the solvent is based on the immersed sample;

(c) static extraction: switching on a switch valve at the inlet of a chromatographic column of the liquid chromatography six-way valve, closing the switch valve, sequentially switching on a purification chromatographic column and an analysis chromatographic column behind the switch valve, setting a solvent gradient and flow rate program of the liquid chromatography, rotating the liquid chromatography six-way valve to a sample injection (inject) position, and when the pressure reaches a specified pressure, keeping the flow rate of a pump to be zero and simultaneously heating the extraction chromatographic column;

(d) dynamic extraction: after the step (c) is kept for a period of time, opening a switch valve, and increasing the flow rate in a flow rate program to perform dynamic extraction, wherein the process is kept for a period of time;

preferably, after the dynamic extraction process is completed, the liquid chromatography six-way valve is screwed to a loading position, and the sample in the analytical chromatographic column is subjected to isocratic elution or gradient elution separation according to the separation condition.

Further, in the step (a), the sample may be filled with a sample and weighed, and the filling amount of the sample may be calculated by peeling.

Further, when gradient elution is adopted for the separation sample, acetonitrile and water are selected as mobile phases.

The invention has the beneficial effects that:

the invention creates a three-stage chromatography integrating extraction, purification, separation and measurement, can complete the whole process of sample treatment and test at one time, saves the steps of concentration, sample transfer and the like, greatly shortens the time cost of the whole measurement process, improves the utilization rate of the sample, reduces the process error and reduces the environmental pollution caused by the evaporation of a large amount of solvent; in addition, in the high-temperature and high-pressure extraction process, new large-scale equipment is not required to be added, and the test cost is reduced.

Drawings

FIG. 1 is a flow diagram of a three-stage chromatographic assay;

FIG. 2 is a liquid chromatography six-way valve loading (load) position state flow diagram;

FIG. 3 is a schematic diagram of the position state of a six-way valve sample injection (inject) of a liquid chromatograph;

description of reference numerals:

1, a liquid phase six-way valve sample outlet; 2: a liquid phase six-way valve sample inlet; 3. 6: liquid phase six-way valve dosing ring (loop) position; 4: a liquid phase six-way valve chromatographic column inlet; 5: a liquid phase six-way valve mobile phase inlet;

7: extracting a chromatographic column; 8: an on-off valve; 9: purifying the chromatographic column; 10: an analytical chromatographic column;

11: a pump; 12: a liquid chromatography six-way valve; 13: heating device

Detailed Description

To show the details of the present invention more clearly, the following explanation is first made for the three-stage chromatography:

the third-stage chromatography comprises loading the sample to be measured into a chromatographic column, extracting at high temperature and high pressure, eluting the extract by chromatography, wherein the process is first-stage chromatography, filtering and purifying the extracted sample by chromatography, wherein the process is second-stage chromatography, and finally, carrying out chromatographic separation and analysis on the purified sample, wherein the process is third-stage chromatography measurement.

The specific process is described below with reference to the embodiments.

In this example, soil is used as a sample material.

Firstly, soil sampling and wet sampling are carried out: the soil sample is made into particles of 60-80 meshes, the weighed sample amount is calculated to be about 0.1g by utilizing a full sample weighing and peeling method in a proper extraction chromatographic column 7, then the extraction chromatographic column 7 is connected in series to the position of a quantitative ring (loop) of a liquid chromatogram six-way valve, the liquid chromatogram six-way valve 12 is screwed to the position of a sample loading (load), the communication state of the liquid chromatogram six-way valve is shown in figure 2, a micro-injector is used for injecting extraction solvent acetonitrile from a sample injection port 2 of the liquid chromatogram six-way valve, the dosage of the extraction solvent acetonitrile is based on an immersed sample, the dosage of the solvent is very small, and the solvent is collected in a waste liquid bottle along with a mobile phase, so that the environment is hardly polluted.

After completion of the wet sample, static extraction was started: switching on a switch valve 8 at the inlet of the chromatographic column of the liquid chromatogram six-way valve, closing the switch valve 8, sequentially switching on a purification chromatographic column 9 and an analysis chromatographic column 10 behind the switch valve 8 to prepare for the subsequent purification and analysis integration, setting the gradient and flow rate program of the liquid chromatogram solvent after the steps are completed, and rotating the liquid chromatogram six-way valve 12 to sample injection (in)ject) position, when the pressure reaches the given pressure, the flow rate of the pump 11 is kept at zero, while the extraction column 7 is heated, since the extraction pressure is higher than the extraction pressure of the fast solvent, the boiling point of the solvent acetonitrile is much higher than that of the same solvent when using the fast solvent extractor, physico-chemical tells us that the temperature is increased by 10 ℃, the reaction (extraction) speed is increased by 2-4 times, and the extraction temperature is increased from 50 ℃ (soxhlet extraction temperature) to 150 ℃ (high-pressure high-temperature extraction temperature) estimated as 2 times as the lower limit, and the extraction speed is increased by 2 times¹⁰The original effect of 18 hours (1080 minutes) extraction is equivalent to that of 1 minute extraction at 150 ℃, so that the extraction time is greatly shortened.

The above process is static extraction, after the state is kept for 5min, the on-off valve 8 is opened, meanwhile, the flow rate is increased to 0.1ml/min in the flow rate program to carry out dynamic extraction, in the process, the extract flows through the purification chromatographic column 9 to the analysis chromatographic column 10, the extract is only distributed on the analysis chromatographic column head 10 due to small flow rate, in addition, the extracting agent is high-temperature high-pressure acetonitrile in the extraction process, the solvent is rapidly cooled after flowing out of the extraction column, and the process is kept for 2min until the extraction is finished.

After extraction is finished, the liquid chromatography six-way valve 12 is screwed to a sampling (load) position, a mobile phase directly flows through the chromatographic column inlet 4 of the liquid chromatography six-way valve 12 from the mobile phase inlet 5 of the liquid chromatography six-way valve 12, then flows through the purification chromatographic column 9 through the switch valve 8 to reach the analysis chromatographic column 10, in the analysis chromatographic column 10, a component to be detected is well separated and measured, and the time required in the process is the same as that required by the single analysis chromatographic column.

The gradient program for the above procedure is as follows:

T(min)	water%	Acetonitrile%	Flow rate ml/min	Remarks for note
					0	60	40	1	Without sample introduction
0.001	0	100	0.1	After sample introduction, the switch valve is closed
					0.00x	0	100	0	After the pressure is reached, the pump flow rate is set to zero to start static extraction
5.00	0	100	0	Static high-temperature high-pressure extraction for 0.00X-5.00 min with X not less than 1
					7	0	100	0.1	Dynamic hot-pressing chromatographic extraction 5-7 min 5min opening and closing valve
7.01	60	40	1.0	Switching the sample injector to load mobile phase to directly enter the analytical column
					40	5	95	1.0	Normal gradient elution separation analysis for 7.01-40 min
50	5	95	1.0	Separating and analyzing for 40-50 min
					50.1	60	40	1.0	Is restored to the initial state

It can be seen that the whole process has no sample transfer concentration step and adopts the integration of chromatographic extraction, purification and analysis, thereby shortening the time cost of the whole determination process, improving the utilization rate of the sample, reducing the process error and reducing the environmental pollution caused by the evaporation of a large amount of solvent; in addition, in the high-temperature and high-pressure extraction process, new large-scale equipment is not required to be added, and the test cost is reduced.

The invention described above is only a preferred implementation method, and the protection scope of the invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the invention belong to the protection scope of the invention. It should be noted that several variations without departing from the principle of the method of the invention should be considered as the protection scope of the invention for a person skilled in the art.