Quantitative Thin Layer Chromatographic Determination of Furazolidone and Nitrofurazone in Animal Feeds

Abstract A method is presented for determining the nitrofurans furazolidone and nitrofurazone in animal feeds. The sample is extracted with acetone, and aliquots of the concentrated extract are spotted on thin layer chromatographic fluorescent plates. After development in CHCl3-methanol (90+10), the bands containing the nitrofurans are detected under shortwave ultraviolet light, scraped from the plate, and extracted with ethanol. The centrifuged extracts are scanned from 500 to 300 nm on a recording spectrophotometer with a tungsten lamp, and the absorbance maxima near 360 nm are used for quantitation. To compensate for extraction and chromatographic losses and for other interferences, the nitrofuran not present in the sample is added as an internal standard. The method is generally not applicable at a level below 0.005% since detection of the bands becomes difficult.