目的 建立定量检测谷氨酸中细菌内毒素的方法,并验证其可行性。方法 依据《中国药典》2020年版通则1143细菌内毒素检查法中动态显色法的标准,采用两个厂家的鲎试剂,通过细菌内毒素标准曲线的可靠性验证实验、供试品前处理中所用试剂钙离子缓冲液及磷酸氢铵钠的干扰实验、供试品的干扰实验及外加内毒素回收实验,成功建立了谷氨酸中细菌内毒素的检测方法,并对3批供试品进行了定量检测。结果 将供试品与磷酸氢铵钠一起溶解,配制成质量浓度为20 mg·mL^-1的谷氨酸溶液,以钙离子缓冲液稀释至5 mg·mL^-1以下,对细菌内毒素检查无干扰作用。3批供试品的内毒素含量均小于限值12 EU·g^-1,相对标准偏差(RSD)均<10%,阳性回收率在50%~200%,符合规定。结论 本研究所建立的细菌内毒素检查方法可用于谷氨酸的细菌内毒素检查,控制其产品质量。

OBJECTIVE To establish a method for the quantitative detection of bacterial endotoxin in glutamic acid and verify its feasibility. METHODS Verification test of the reliability of bacterial endotoxin standard curve, interference test of calcium ion buffer and sodium ammonium hydrogen phosphate used in pre-treatment, and interference test of test product and additional endotoxin recovery test were carried out in sequence by using limulus reagents from two manufacturers according to the standard of kinetic chromogenic assay in bacterial endotoxin inspection method (General Chapter 1143 in Chinese Pharmacopoeia2020 Edition). A method for the detection of bacterial endotoxin in glutamic acid was successfully established, and three batches of samples were quantitatively detected by this method. RESULTS Glutamic acid was dissolved with sodium ammonium hydrogen phosphate together to the concentration of 20 mg·mL^-1, then diluted by calcium ion buffer to the concentration of 5 mg·mL^-1, which had no interference effects on bacterial endotoxin test. The contents of endotoxin in three batches of samples were all lower than the limit of 12 EU·g^-1, the RSD values were all lower than 10%, and the endotoxin recovery rates were in the range of 50% to 200%, which met the requirements. CONCLUSION The bacterial endotoxin test method established in this study can be used to detect the bacterial endotoxin in glutamic acid and control its quality.