Liquid chromatographic-electrochemical detection screening procedure for six nitro-containing drugs in chicken...

A screening procedure is described for the detection of furazolidone, nitrofurazone, aklomide, zoalene, nitromide, and sulfanitran residues in a single extract of chicken liver, breast, or thigh muscle at the low ppb level. The method includes extraction of tissue with chloroformethyl acetate-dimethyl sulfoxide (50 + 50 + 0.8), adsorption on neutral alumina, and subsequent elution of the residues with pH 6.0 phosphate buffer-methanol (1 + 1). Eluants are separated on a 25 cm, 5 microns C18 column with pH 6.0 phosphate buffer-methanol (57.5 + 42.5) as mobile phase. The drugs are detected with an electrochemical detector in the reductive mode at -0.8 V. Mean recoveries from all tissues ranged from 76.5% for nitrofurazone to 97.1% for zoalene.