Fluorescence HPLC determination of streptomycin in meat using ninhydrin as a postcolumn labeling agent

A rapid, simple and accurate method for the determination of streptomycin (SM) in meat by HPLC was developed. The method includes extraction with perchloric acid solution and clean-up using a C8 pretreatment column. A 18 ml of the mixture of a edible tissue extract and the buffer solution including ion pair reagent was poured into a pretreatment column, and the column was washed with 5 ml each of water and 30% methanol solution successively. Streptomycin was eluted from the column with 3 ml of methanol. The eluate was concentrated to 0.1 ml under nitrogen stream, and adjusted to 1.0 ml with 5 mM sodium 1-octanesulfonate solution (pH 3.3). Then a 10 μl aliquot of the solution was injected into the HPLC system. The HPLC condition was as follows : column, Nucleosil 5C18 (5 μm, 250 mm×4.6 mm i.d.); mobile phase, water-acetonitrile (86 : 14) containing 20 mM disodium 1, 2-ethanedisulfonate, 5 mM sodium 1-octanesulfonate and 5 mM ninhydrin (pH 3.3); flow rate, 1.2 ml/min; column temp., 60 °C; detection, fluorescence Ex. 400 nm, Em. 495 nm; reaction coil, stainless steel tube (10 m × 0.5 mm i.d.); reaction solution, 0.3 M sodium hydroxide solution; flow rate, 0.3 ml/min; reaction temp., 80°C. A linear regression analysis of the calibration curve obtained from the standard solution (0.050.5 μg) yielded the equation Y=0.64X+0.26, r=0.9970. The recovery of SM added to chicken meat at the level of 2 μg/g was 66.7%. The detection limit of SM was 0.5 μg/g.