Determination of pesticides in the hair of Vietnamese by means of supercritical CO2 extraction and GC–MS analysis

A supercritical fluid extraction (SFE) and clean-up procedures were established for isolating organochlorines (OCPs) and organophosphorus pesticides (OPPs) from the hair of the Vietnamese test subjects. The study of dependence of the yields of pesticides on some parameters of the supercritical fluid CO2 extraction (P, T and τ) was carried out. Eight OCPs and OPPs were determined by SFE with carbon dioxide only and methanol-modified carbon dioxide extraction at 350 bar, 60 min and 45 °C, followed by gas chromatography coupled to mass spectrometry. The results indicated that OCPs can be extracted quantitatively using CO2 only, whereas OPPs require a modifier for extraction. The limit of detection for the 200 mg sample of hair has been found between 0.7 and 1.3 μg g−1, and good linearity (r2 > 0.9861) was achieved within the tested ranges.