A new and fast high-performance liquid chromatography (HPLC) method using technology of fused-core columns for separation of fenoxycarb and cis-, trans-permethrin has been developed and used for their determination in antiparasitic veterinary shampoo. Separation of insecticides and internal standard sudan II was achieved on the fused-core column Ascentis Express RP-Amide (100 x 3.0 mm), particle size 2.7 mu m, with mobile phase acetonitrile/water (55:45, v/v) at a flow rate of 1.0 mL min(-1) and at temperature 60 A degrees C.
The detection wavelength of detector was set at 225 nm for both compounds and internal standard sudan II. Under the optimum chromatographic conditions standard calibration curves were measured with good linearity [r (2) = 0.99991 for fenoxycarb, r (2) = 0.99987 for trans-permethrin, and r (2) = 0.99984 for cis-permethrin (n = 8)].
Commercial samples of antiparasitic veterinary shampoo were extracted with ethanol in ultrasound bath for 5 min. A 2-mu L sample volume of the filtered solution was directly injected into the HPLC system.
Accuracy of the method defined as a mean recovery of insecticides from shampoo matrix was in the range 100.43-103.85 % for both insecticides.