On-column Injection Coupled with Gas Chromatography/Mass Spectrometry for Determination of Thermoliable Carbamates Pesticides in Animal Derived Sample
The feasibility and reliability of using on-column injection-gas chromatography/mass spectrometry(GC/MS) for the determination of thermo-liable carbamates pesticides in complex matrices has been investigated.The thermal instability of 13 carbamates pesticides was evaluated with conventional splitless injector and on-column injector.According to the properties of pig,egg and milk samples studied,the present method was involved in extraction with acetonitrile and cleanup with Gel permeation chromatography(GPC) and N-alumina SPE followed by on-column injection-GC/MS determination.The average recovery was in the range of 81%-90% with RSD in the range of 2.8%-6.0% at different spiked levels.The LOQs for pesticides were 0.01 mg/kg.The long-term stability by using on-column injection was studied and normal chromatographic performance could be obtained within 80 analyses