GC Determination of Residual Amounts of Pyrethriod Insecticides in Cigarette Filter Tips after Smoking

Smoking machine conformed to the standard of ISO 30008 was used for sampling. Sample of the cigarette filter tips was collected and extracted ultrasonically with mixed solvent of ethyl acetate and cyclohexane (1+1) for 30 min. The extract was dehydrated with anhy. Na2SO4 and evaporated to near dryness by a rotary evaporator. The residue was taken up in 2 mL of n-hexane and the solution obtained was purified by SPE on graphite carbon black micro-column, which was eluted twice with mixture of acetone and n-hexane (2+8). The eluates were combined, concentrated by rotary evaporation and made up to 1.5 mL with the same mixed solvent which was used for GC analysis with Agilent HP-5 column for separation, and ECD for detection. Four pyrethriods were determined giving their values of RSD′s (n=5) less than 6%. An equivalent of 20 μg of the mixed standard of the 4 pyrethroids was added to a sample containing 20 filter tips, and values of recovery found were all over 92%.