Unruh J, Schwartz D P, Barford R A
U.S. Department of Agriculture, Eastern Regional Research Center, Philadelphia, PA 19118.
J AOAC Int. 1993 Mar-Apr;76(2):335-41.
Our earlier method to detect and quantitate sulfamethazine (SMZ) in milk at the 10 ppb level was modified to quantitate SMZ in pork tissue. Sulfabromomethazine (SBZ) is added to the tissue as an internal standard. SMZ and SBZ are extracted from the tissue into water as the supernatant of a centrifuged, aqueous homogenate and are cleaned up and concentrated by a series of solid-phase extractions. The sulfonamide-containing eluate is then separated on a silica gel thin-layer chromatographic plate. SBZ and SMZ are derivatized with fluorescamine, and their fluorescence is quantitated with a scanning densitometer. The limit of detection was estimated at 0.25 ppb (signal-to-noise ratio, 3:1). The average accuracy over the analysis range (0.54-21.8 ppb [micrograms/kg]) was 95.6% (standard deviation = 29.4%, n = 54).
我们早期用于检测和定量牛奶中浓度为10 ppb的磺胺二甲嘧啶（SMZ）的方法经过改进，用于定量猪肉组织中的SMZ。向组织中添加磺胺溴甲嘧啶（SBZ）作为内标。SMZ和SBZ从组织中作为离心后的水性匀浆上清液萃取到水中，并通过一系列固相萃取进行净化和浓缩。然后将含磺胺类药物的洗脱液在硅胶薄层色谱板上分离。SBZ和SMZ用荧光胺衍生化，并用扫描密度计对其荧光进行定量。检测限估计为0.25 ppb（信噪比为3:1）。分析范围内（0.54 - 21.8 ppb [微克/千克]）的平均准确度为95.6%（标准差 = 29.4%，n = 54）。
