Multiresidue determination of organophosphorus and organochlorine pesticides in human biological fluids by capillary gas chromatography

Two multiresidue analytical methods for the simultaneous determination of o rganophosphorus and organochlorine pesticides in human urine and serum samp les are described. The first approach is based on liquid-liquid microextrac tion with dichloromethane, and the second uses solid-phase extraction with C-18 In both methods, the extracts are analyzed by capillary gas chromatogr aphy using nitrogen-phosphorus detection (NPD) and electron-capture detecti on (ECD). Limits of detection of the overall procedure of analysis are at t he low ng mL(-1) level. Stability experiments have been performed with spik ed urine and serum samples stored at 4 degreesC for 1 month. Finally, the s olid-phase extraction procedure was applied to real-world samples. Quantifi cation was performed by NPD or ECD, and peak identity was confirmed by use of mass-selective detection (MSD).