Rapid analysis of pyrethroids in whole urine by high-performance liquid chromatography using a monolithic column and off-line preconcentration in a restricted access material cartridge

A rapid high-performance liquid chromatography ( HPLC) method using a monolithic column with UV detection at 238 nm was developed for the determination of fenpropathrin, betacy. uthrin, deltamethrin, and permethrin ( cis and trans isomers) in whole urine. The method is based on the use of a monolithic chromatographic column and a restricted access material ( RAM) cartridge for sample preparation. The mobile phase was water/acetonitrile (42: 58 v/v), the flow rate was 3 mL min(-1), and chromatographic separation was carried out in 10 min. The separation of cis and trans isomers of permethrin was also possible under the above-mentioned conditions. Detection limits in reconstituted whole urine samples were between 0.9 lg L-1 for betacy. uthrin and 4.4 mu g L-1 for fenpropathrin and transpermethrin. Recoveries for urine samples spiked with different amounts of pyrethroids (between 19 mu g L-1 and 75 mu g L-1) were in the 70 +/- 6 to 90 +/- 7% range.