离子色谱安培法检测维生素B₆与2-噻吩乙酸中的氰化物

目的：建立离子色谱积分安培法检测维生素B₆（VB₆）与2-噻吩乙酸（2-TPA）2种合成药物中的氰化物。方法：维生素B₆经甲醇溶解后，加入氢氧化钠溶液溶解萃取；2-噻吩乙酸经热氢氧化钠溶液超声溶解，定容，经0.22 μm的尼龙滤膜和On Guard RP柱处理后进入离子色谱分析。使用IonPac AS18（250 mm×4 mm）阴离子交换色谱柱和IonPac AG18（50 mm×4 mm）保护柱，20 mmol·L^-1氢氧化钠淋洗液，安培检测器。结果：在优化的色谱条件下，水中氰在0.20~10.0 mg·L^-1范围内呈良好线性，线性相关系数为0.999 9，最低检出限（S/N≥3）为1.64 μg·L^-1，实际合成药物中CN^-的检出限为0.016 4 μg·g^-1，样品的加标回收率为92.4%~97.9%。维生素B₆（VB₆-1，VB₆-2，VB₆-Y1，VB₆-Y2）粗产品与2-噻吩乙酸（2-TPA-1，2-TPA-2）原料样品中，VB₆-1中未检出氰化物；VB₆-2中氰离子的含量为0.823 μg·g^-1；VB₆-Y1中氰离子的含量为117.1 μg·g^-1；VB₆-Y2中氰离子的含量为1.872 μg·g^-1；2-TPA-1中氰离子的含量为118.7 μg·g^-1；2-TPA-2中未检出氰化物。因此，合成原料和粗产品中含有一定的氰化物，精制产品中的氰化物含量很低，甚至有的低于检出限而未检出。结论：本文方法前处理简单，环境友好，受其他杂质的干扰较小，灵敏度高，经方法学验证可用于评价VB₆与2-噻吩乙酸药物中氰化物的含量。

Objective: To establish a method for the determination of cyanide in vitamin B₆(VB₆)and 2-thiopheneacetic acid(2-TPA)drugs by ion chromatography with integrated amperometric detector.Methods: The certain quality of VB₆ was dissolved in methanol and sodium hydroxide solution,2-TPA was dissolved in hot sodium hydroxide solution.All the solutions were pre-treated by 0.22 μm nylon filter membrane and a Guard RP column.The solutions were then analyzed by IC.The chromatography column was IonPac AS18(250 mm×4 mm)and IonPac AG18(50 mm×4 mm).The eluent was 20 mmol·L^-1 NaOH with 1.0 mL·min^-1 flow rate.The amperometric detector was used.Results: With the optimum conditions,the CN^-was linear in the range of 0.20-10.0 mg·L^-1 with correlation coefficient of 0.999 9.The method LOD for CN^- was 0.016 4 μg·g^-1.The recoveries ranged of 92.4%-97.9%.Multiple VB₆ and 2-TPA samples were assessed.The content of cyanide was not detected in VB₆-1.The content of CN^- was 0.823 μg·g^-1 in VB₆-2,117.1 μg·g^-1 in VB₆-Y1,1.872 μg·g^-1 in VB₆-Y2 and 118.7 μg·g^-1 in 2-TPA-1.The content of cyanide was not detected in 2-TPA-2.Synthetic raw materials and crude products contained a certain amount of cyanide;the cyanide could not be detected or was so low in the refined products.Conclusion: By methodology verification,this method requires simple pretreatment,has high repeatability,without pollution and with little interference.This method had been applied to assess the content of cyanide in VB₆ and 2-TPA.