ABSTRACT
A novel method for simultaneous determination of 3 rat poisons ( tetramine, bromadiolone, brodifacoum) and 5 toxic alkaloids ( hyoscyamine, scopolamine, gelsemine, strychnine, brucine ) in toxic samples by dispersive liquid-liquid micro-extraction ( DLLME ) coupled with gas chromatography-mass spectrometry was established. A mixture extractant containing 100 μL trichloromethane and 600 μL methanol was injected into the prepared sample to form an emulsion and the extraction process was accomplished. After centrifuged at 8000 r/min for 5 min, the settled drop of trichloromethane solvent was transferred to a conical insert within a GC autosampler vessel, and analyzed by GC-MS. Factors affecting extraction efficiency such as the type and volume of extractant, dispersive agent, extraction time, pH value and salt concentration of extraction system were studied. The limits of detection(LODs) were from 0. 003 to 1 μg/L in water sample, urine sample and rice wine sample. LODs were from 0. 002 to 0. 2 μg/kg in rice sample. The recoveries of toxic samples were in the range of 81. 0%-110%. The relative standard deviations( RSDs) were lower than 7%. The proposed method was sensitive, effective, and suitable for the simultaneous determination of toxic alkaloids and rat poisons in food poisoning sample.