Application of restricted-access media column in coupled-column RPLC with UV detection and electrospray mass spectrometry for determination of azole pesticides in urine

Triadimenol, triadimefon and tetraconazole were simultaneously determined i n human urine by coupled-column liquid chromatography with both UV and ES-M S detection. These procedures were validated and the values of some merit f igures, such as, linear range, detection limits, precision and recovery, ob tained with both methods, are compared. A 5 mum GFF-II, internal-surface, r eversed-phase (ISRP: Pinkerton) column coupled to a 3 mum reversed-phase, M icrosphere C18 column were used. To increase sensitivity a solid-phase extr action step with C18 cartridge was carried outyielding recoveries 80 - 107% (n = 5) with RSD 3 - 8% for the LC-LC-UV method and 88 - 108% (n = 5), RSD 5 - 11% for the IC-ES-MS method. limits of detection were 1.5 - 3.5 mug L- 1 for LC-LC-UV and 0.5 - 1.0 mug L-1 for LC-ES-MS. The methods were employe d to detect and quantify pesticides in urine of pest control operators and non-occupationally exposed subjects.