DETECTION OF ANTICOAGULANT RODENTICIDES (4-HYDROXYCOUMARINS) BY THIN-LAYER CHROMATOGRAPHY AND REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

The detection of 4-hydroxycoumarin rodenticides in poisoned domestic a nimals requires a highly sensitive method as tissue and serum levels o f anticoagulants may be very low owing to rapid elimination, metabolis m or post-mortem degradation. Thin-layer chromatography (TLC) and reve rsed-phase high-performance liquid chromatography (RP-HPLC) with fluor escence detection were used to identify the anticoagulants in spiked t issues and in suspicious samples. The analysis of ten suspicious sampl es highlighted the limitations of both methods. Only the three samples of baits were found positive by TLC whereas one of the five anticoagu lants was detected in eight samples by RP-HPLC with fluorescence detec tion. Therefore, RP-HPLC with fluorescence detection proved to be the more sensitive method for detecting low levels of It-hydroxycoumarins in blood serum, liver and ingesta, whereas TLC is usually sufficient f or analysing baits.