COMPARISON OF MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHIC METHOD WITH HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF IMIDAZOLIDINE-2-THIONE (ETHYLENETHIOUREA) IN FORMULATED PRODUCTS

A micellar electrokinetic capillary chromatographic (MECC) method was developed for routine analysis of the carcinogenic compound imidazolid ine-2-thione (ETU) in commercial ethylenebis-(dithiocarbamate) fungici des (EBDC). The MECC method was compared with a previously developed h igh-performance liquid chromatographic (HPLC) method. Both methods dem onstrated good precision, accuracy, linearity, and sensitivity. The re lative standard deviations (RSD) for precision ranged from 0.04 to 5.0 9% for the MECC method and from 0.47-5.22% for the HPLC method. The re coveries for accuracy ranged from 98.3 to 100.6% for the MECC method a nd from 99.5 to 104.9% for the HPLC method. No matrix interference was observed in either method. The column efficiency of MECC (N = 12491) was 15 times higher than that of HPLC (N = 813). The instrument detect ion limit (IDL) and the method detection limit (MDL) of the MECC metho d were 0.25 and 0.30 mu g/mL, which were 25 and 15 times higher than t he IDL (0.01 mu g/mL) and the MDL (0.02 mu g/mL) of the HPLC method, r espectively. The most important advantages of the MECC method over the HPLC method are the shorter run time and the reduction in solvent was te. The total run times for analyzing a sample were 11 min for the MEC C method and 15 min for the HPLC method, and the volume of waste solve nt for the MECC method (49.0 mu L/sample) was 153 times less than that for the HPLC method (7.5 mL/sample). This research has proven that th e routine ETU analysis in formulated EBDC products by the MECC method is comparable with traditional the HPLC method and the MECC method is better than the HPLC method if the run time and the cost of solvent ar e considered.