A dynamic headspace liquid phase microextraction method based on extraction solvent volatilization

Abstract

The invention discloses a dynamic headspace liquid-phase micro-extraction method based on extracting solvent evaporation. A certain volume of an extracting solvent is sucked by a microsyringe, a needle of the microsyringe is inserted into a headspace sample bottle, a needle point is located above a sample, the microsyringe is pushed by a micro-injection pump at a certain speed, the pushing speed keeps balance with the volatilization speed of the extracting solvent, a droplet formed by the extracting solvent at the needle point is enabled to be kept on a non-falling level all along, the droplet at the needle point is drawn back to the microsyringe after injection of the extracting solvent is finished, an extracting process is finished, and the extracting solvent is directly subjected to chromatographic sample introduction analysis through the microsyringe. With adoption of the method, not only is the problem about stability of the extracting droplet hung at the needle point of the microsyringe in the headspace liquid-phase extraction process solved, but also easily volatile solvents with low boiling points can be used as the extracting solvents.

Description

technical field [0001] The invention relates to a dynamic headspace liquid-phase microextraction method based on extraction solvent volatilization, which is used for realizing the headspace extraction of a target compound by using a micro-syringe to suspend liquid droplets of a volatile extractant. Background technique [0002] Single drop liquid phase microextraction is a microextraction technique that uses a small amount of extraction solvent to extract target compounds from a sample, Jeannot M A, Cantwell F F. Mass transfer characteristics of solvenxtraction into a single drop at the tip of a syringe needle. Analytical Chemistry, 1997, 69 (2): 235-239. The general operation method is: draw a few microliters of extraction solvent with a micro-syringe, insert the needle of the syringe vertically into the sample bottle, and place the needle point of the syringe above the sample to be extracted, or place it on the Then push the plunger of the syringe to push the droplet out a...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the problem of contradiction between the stability of the suspended droplet of the needle point of the micro-syringe and the low boiling point and volatile solvent as the extraction agent in the headspace single-drop liquid phase micro-extraction method, and to provide a micro-syringe As the carrier of the extractant, the low boiling point solvent is used as the extractant, and the dynamic headspace liquid phase microextraction method with the volatile characteristics of the low boiling point extractant is used

This method not only solves the problem of the stability of the extraction droplets suspended from the tip of the micro-syringe during the extraction process, but also enables the use of low-boiling point, volatile solvents as extraction agents.

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