High-Performance Liquid Chromatographic Determination of Carbadox, Olaquindox, Furazolidone, Nitrofurazone, and Nitrovin in Feed

Abstract

A high-performance liquid chromatography with gradient programming method was developed to determine the amount of carbadox (CBX), olaquindox (OLQ), furazolidone (FZ), nitrofurazone (NF), and nitrovin (NTV) in feed simultaneously. Complete separation of the drugs was obtained using a C8 silica gel column with gradients of acetonitrile as mobile phase. The mobile phase used an acetonitrile gradient with an initial hold time of 1 min at 0% acetonitrile, followed by an increase to 50% acetonitrile over 10 min. The correlation coefficients (r) for calibration curves of the five feed additives were greater than 0.999. The relative standard deviations (RSDs) of peak areas from four injections for these drugs at three concentrations were less than 3.0%, although the RSD for NTV at 5 ppm was somewhat large (6.7%). The medicated feeds were extracted by pretreating with water, extracted with 95% dimethylformamide overnight at room temperature, and cleaned up on a column of alumina oxide. Recoveries of CBX, OLQ, FZ, NF, and NTV from low level spiked feed were 102.0, 94.6, 97.4, 110.6, and 66.0%, respectively, and from high level spiked feed, they were 114.09, 99.1, 97.3, 109.9, and 62.7%, respectively.