Sample pretreatment method of microextraction tube injection

A sample pretreatment method of microextraction tube injection, comprising:

• providing a capillary micro-extraction tube with extracting medium in it as an injector,
• passing a sample through the capillary micro-extraction tube, during which an analyte is extracted into the extracting medium inside the capillary micro-extraction tube;
• then, filling the capillary micro-extraction tube with an organic solvent and keeping the filling for a certain period of time, so that the extracted analyte is dissolved in the organic solvent inside the capillary micro-extraction tube to form an injection solution;
• and
• finally, keeping one end of the capillary micro-extraction tube sealed and inserting the open end directly into an injection port of a gas chromatography, such that the injection solution is automatically ejected out from the capillary micro-extraction tube into the injection port to complete the injection operation for gas chromatography;
• wherein, the extracting medium inside the capillary micro-extraction tube does not exceed 90% of the total internal volume of the capillary micro-extraction tube;
• the organic solvent is kept in the capillary micro-extraction tube for a period of no more than 45 min;
• the sample solution flows through the capillary micro-extraction tube at a flow rate not exceeding 1 mL/min.