MP5 Agrochemicals and Pesticides
Monday, 14 November 2005: 8:00 AM - 5:30 PM in Exhibit Hall

(ROB-1117-816116) Multi-residue method for the determination of five synthetic pyrethroids in environmental water samples using SPME with negative ion chemical ionisation mass spectrometry detection.

Robinson, N J¹, Olberding, E², Lam, C³, Chen, A⁴, Sharma, A K⁵, ¹ Syngenta, Bracknell, Berkshire, UK² Dow Agrosciences, Indianapolis, IN, USA³ Bayer CropScience, USA⁴ FMC Corporation, Princeton, NJ, USA⁵ DuPont Crop Protection, USA

ABSTRACT- A multi-residue analytical method has been developed for the analysis of five synthetic pyrethroid insecticides (lambda-cyhalothrin, esfenvalerate, cyfluthrin, cypermethrin and bifenthrin) in environmental water samples. The method utilises solid phase microextraction (SPME) of the water sample followed by gas chromatography with negative ion chemical ionisation mass spectrometry (GC-NICI) detection. The sensitivity of the SPME sampling technique coupled with the high sensitivity and selectivity of the GC-NICI detector allow low part per trillion amounts of pyrethroid insecticides to be measured by direct analysis of the water sample without the need for sample pre-concentration. The poster will describe the analytical method and compare the sensitivity of SPME versus conventional liquid/liquid partition methods. Analyte concentrations determined by the two methods will be compared to assess differences between truly aqueous concentrations and total water concentrations, i.e. aqueous plus that associated with particulate and dissolved organic carbon. This approach is relevant to the evaluation of bioavailable fractions in aqueous systems.

Key words: Pyrethroids, SPME, Multi-residue method