Replacement of Gas Chromatography Deoxidizer Tube and Adsorption of Organophosphorus Pesticides by Active Sites in GC System

There are two types of deoxidizers, one is where the internal deoxidizer can be observed, and the other is an all-metal shell, where the internal deoxidizer cannot be observed

Due to the high price and small capacity of the deaeration tube, care must be taken when replacing it to avoid oxygen entering during the replacement

(1) Turn on the carrier gas a bit and let the carrier gas vent through the connector at a slower speed

(2) Loosen the screw on the inlet end of the deoxidizer tube, move it to the side of the carrier gas connector, quickly unscrew the screw while flushing the deoxidizer tube connector with carrier gas, and connect the carrier gas connector

(3) After tightening the inlet end interface, loosen the outlet end screw.

(4) Maintain the carrier gas supply, remove the screws, quickly connect the pipeline joints, check the air tightness, and the replacement is complete

Therefore, when replacing the cylinder, pay attention to the replacement of the air in the decompression table

Organophosphorus pesticides refer to organophosphorus compounds containing phosphorus

So what should be paid attention to when analyzing organophosphorus pesticide residues by GC? How to avoid the adsorption of pesticides at each active site in the system?

You can start from the following aspects: ①Replace the liner and quartz wool, and add a few more injections of matrix sample or high-concentration standard solution to saturate the sample before sampling to cover up the active sites; ②Increase the use of protective agents for sample analysis , Such as sorbitol, etc.

Due to long-term use, a large amount of high-boiling substances often accumulate in the vaporization chamber and liner.