Determination of acaricides in honey by liquid chromatography with ordinary, narrow-bore, and microbore columns

Narrow-bore and microbore columns packed with octadecylsilane were used to compare their sensitivity and efficiency in the separation of coumaphos, fluvalinate, bromopropylate, and 4,4'-dibromobenzophenone from honey with those of ordinary columns. The best sensitivity for acaricides was accomplished by using a 150 mm × 0.32 mm i.d., 5 μm Spherisorb ODS-2 capillary column, methanol-water (90:10 v/v) as the mobile phase, and 5 μL/min as the flow rate. Detection limits for individual acaricides using a UV detection range from 0.40 to 0.74 μg/kg of honey were comparable to those obtained by gas chromatography using an electron capture detector. All acaricides were separated in <12 min. The coefficients of variations on real samples were <6.2%.