离子色谱-直接电导法检测盐酸二甲双胍药物中二甲胺的残留

Determination of dimethylamine residues in metformin hydrochloride substances by ion chromatography

目的:建立离子色谱-直接电导法测定盐酸二甲双胍药物中二甲胺残留的方法。方法:盐酸二甲双胍药物用水溶解后直接进样,采用20 mmol·L^(-1)甲磺酸水溶液为淋洗液,以Dionex Ionpac CS12A(4 mm×250 mm)色谱柱进行分离,流速为1.0 m L·min^(-1),CSRS 500-4 mm阳离子抑制器和电导检测器抑制并直接检测,抑制电流60 m A,柱温30℃,进样体积25μL。结果:二甲胺在0.1~10.0μg·m L^(-1)范围内线性关系良好(r=0.999 4),方法的检测限为0.032 8μg·m L^(-1)(S/N=3),方法的定量下限为0.12μg·m L^(-1)(S/N=10),平均回收率为97.6%~99.5%,RSD均不超过3%。结论:该方法操作简单、灵敏度高、重现性好,可用于盐酸二甲双胍药物中二甲胺残留的检测。

Objective： To establish an ion chromatography method for the determination of dimethylamine residues in metformin hydrochloride substances. Method： After dissolved by water, the sample solution was loaded onto the instrument. The determination was performed on a Dionex Ionpac CS12A （ 4 mm × 250 mm ） column. The eluent was 20 mmol · L-1 methanesulfonic acid solution at a flow rate of 1.0 mL· min-1. Dimethylamine was detected by suppressed conductivity with a CERS 500-4 mm suppressor at a current of 60 mA, the column temperature was 30 ℃ and the injection volume was 25 μL. Results： The calibration curves showed good linearity in the range of 0.1-10.0 μg· mL-1 （ r=0.999 4 ） ; the limit of detection （ LOD ） of the method was 0. 0328 μg. mL-1 （ S/N=3 ） and the limit of quantification （ LOQ ） of the method was 0.12 μg. mL-1 （ S/N=10 ）. The recovery of dimethylamine ranged from 97.6 % to 99.5 % with RSD not more than 3% . Conclusion： The method has the advantages of simple operation, high sensitivity, good reproducibility, and can be used for the detection of dimethylamine in metformin hydrochloride substances.