Optimization of High Quality Analytical Methods for the Monitoring of Pyrethroid Mothproofing Agents by Gas Chromatography-Mass Spectrometry Operated in Negative-Ion Chemical Ionization Mode

摘要

An analytical method based on gas chromatography combined with negative-ion chemical ionization mass spectrometry in selected ion monitoring mode has been optimized for the simultaneous determination of five synthetic pyrethroid insecticides in water, sediment, moss and fish tissue. The pyre-throids were originally extracted from the environmental matrices by steam distillation extraction but this has since been superseded by liquid-liquid extraction for water samples and ultrasonic extraction for solid matrices with particular attention for solvent selectivity. Recovery studies were performed on all the environmental matrices for each pyrethroid and the internal standard, mirex. The percentage recoveries ranged from 80.6 #xB1; 5.6 to 116.2 #xB1; 4.3, where n = 4. The limit of quantitation for the method was determined statistically from the linear calibration curve, giving values in the range 0.01 to 4.4pg of material introduced into the system. depending on the pyrethroid in question. The method was applied to environmental samples collected from a contaminated river ecosystem currently being monitored for the target analytes.