Adam L A, Reeves V B
U.S. Food and Drug Administration, Center for Veterinary Medicine, Laurel, MD 20708, USA.
J AOAC Int. 1998 Mar-Apr;81(2):359-67.
The method described detects and confirms presence of pentobarbital residues in dry, extruded feeds at concentrations of 5-20 ppb. Dried feed is ground to a uniform powder and shaken overnight in methanol. A portion of the methanolic extract is evaporated, and the residue is reconstituted in phosphate-buffered saline. The aqueous extract is cleaned with a solid-phase extraction cartridge designed to extract barbiturate residues from biological matrixes. Dimethyl sulfoxide, tetramethylammonium hydroxide, and iodomethane are added to derivatize pentobarbital, 1,3-Dimethyl-pentobarbital is then acidified with dilute hydrochloric acid and extracted with isooctane. The organic layer is transferred and evaporated under a stream of nitrogen. The residue is reconstituted in a small volume of ethyl acetate for analysis by gas chromatography/mass spectrometry. The limit of detection is approximately 0.7 ppb. The method was validated with pentobarbital-fortified feed samples containing high concentrations of meat and bone meal.
所述方法可检测并确认干制挤压饲料中浓度为5 - 20 ppb的戊巴比妥残留。将干饲料研磨成均匀粉末，在甲醇中振荡过夜。取一部分甲醇提取物进行蒸发，残留物用磷酸盐缓冲盐水复溶。水提取物用设计用于从生物基质中提取巴比妥类残留的固相萃取柱进行净化。加入二甲亚砜、四甲基氢氧化铵和碘甲烷使戊巴比妥衍生化，然后用稀盐酸将1,3 - 二甲基戊巴比妥酸化并用异辛烷萃取。转移有机层并在氮气流下蒸发。残留物用少量乙酸乙酯复溶，用于气相色谱/质谱分析。检测限约为0.7 ppb。该方法用含有高浓度肉骨粉的戊巴比妥强化饲料样品进行了验证。
