SIMULTANEOUS DETERMINATION OF NITROFURAZONE AND FURAZOLIDONE IN SHRIMP (PENAEUS-VANNAMEI) MUSCLE-TISSUE BY LIQUID-CHROMATOGRAPHY WITH UV DETECTION

A liquid chromatographic (LC) method was developed for the simultaneou s determination of nitroturazone (NFZ) and furazolidone (FZD) in shrim p muscle tissue. The drugs are extracted from the tissue with acetonit rile, and the lipids and lipophilic pigments are removed from the extr act with hexane. The remaining acetonitrile extract is evaporated by r otary evaporation, and the resultant residues are dissolved with LC-gr ade water, applied to a preconditioned C18 solid-phase extraction colu mn, and eluted with acetonitrile. The acetonitrile eluant is then drie d under nitrogen, and the resultant drug residues are dissolved with m obile phase and filtered. The drugs are determined by LC by using a C1 8 reversed-phase (octyldecylsilyl Hypersil) column, a mobile phase of acetonitrile-1% aqueous acetic acid (25 + 75, v/v), and a photodiode a rray UV detector at 375 nm. NFZ and FZD were determined in shrimp tiss ue at each of 5 spiking levels (64, 32, 16, 8, and 4 ng drug/g tissue) . Absolute recoveries ranged from 70.6 to 78.4%, and relative standard deviations ranged from 4.0 to 13.6%. The limit of detection of pure s tandard of each drug was approximately the equivalent of 1 ng drug/g t issue, and the limit of determination in a sample was 4 ng drug/g tiss ue.