药用辅料乳糖中痕量亚硝酸盐和硝酸盐的离子色谱-电导/紫外检测研究

Determination of Trace Nitrate and Nitrite in Pharmaceutical Lactose by Ion Chromatography-Conductivity/Ultraviolet Detections

目的:建立药用辅料乳糖中痕量亚硝酸盐、硝酸盐的离子色谱-抑制电导(IC-CD)检测法和高效液相色谱-紫外(HPLC-UV)检测法。搭建在线膜抑制系统,结合LC-MS/MS技术进行结构确证,为药用辅料乳糖的前置风险控制提供新的策略。方法:IC-CD检测法和HPLC-UV检测法均采用高容量阴离子交换柱Dionex IonPacTM AS11-HC RFICTM(4.0 mm×250 mm)和保护柱Dionex IonPacTM AS11-HC RFICTM(4.0 mm×50 mm)。IC-CD检测法流动相为氢氧化钾溶液,梯度洗脱,抑制型电导检测器的电导池温度为30℃;HPLC-UV检测法流动相为5 mmol·L^(-1)氢氧化钠溶液,检测波长为210 nm;两种方法的流速均为1.0 mL·min^(-1),柱温均为30℃,进样量均为25μL。结果:两种方法测定亚硝酸根在0.03~10μg·mL^(-1)范围内、硝酸根在0.02~200μg·mL^(-1)范围内线性关系均为良好(r>0.999);亚硝酸根检测限和定量限分别为0.25 ng和0.75 ng,硝酸根检测限和定量限分别为0.25 ng和0.50 ng;回收率在84.00%~100.70%之间;进样精密度RSD(n=6)在0.27%~1.33%之间;均满足检验需求。结论:两种方法均具有灵敏度高、专属性强、分离度好、前处理简单的优势,可表征药用辅料乳糖中痕量亚硝酸盐、硝酸盐的含量,也为其他药用辅料前置风险研究提供新的思路和参考。

Objective:To establish ion chromatography-suppressed conductivity detection(IC-CD)and high performance liquid chromatography-ultraviolet detection(HPLC-UV)methods to determine the contents of trace nitrite and nitrate in pharmaceutical lactose.LC-MS/MS technology was combined with the construction of an online membrane suppression system to confirm the structures.It is to provide new strategies for pre-risk control of pharmaceutical lactose.Methods:The high-capacity anion-exchange column of Dionex IonPacTM AS11-HCR FICTM(4.0 mm×250 mm)and the guard column of Dionex IonPacTM AS11-HCR FICTM(4.0 mm×50 mm)were used for both IC-CD and HPLC-UV methods.In the IC-CD method,potassium hydroxide solution was applied for gradient elution and the suppressed conductivity cell temperature was 30°C.In the HPLC-UV detection method,the mobile phase was 5 mmol·L^(-1)sodium hydroxide solution and the detection wavelength was 210 nm.The flow rates and column temperatures of the two methods were set at 1.0 mL·min^(-1)and 30℃,respectively.The injection volumes were 25μL.Results:The two determination methods had good linear relationship(r>0.999)for nitrite in the range of 0.03-10μg·mL^(-1),and for nitrate in the range of 0.02-200μg·mL^(-1),while the LOD and LOQ were 0.25 ng and 0.75 ng for nitrite,0.25 ng and 0.50 ng for nitrate,respectively.The recoveries were between 84.00%-100.70%.The RSD(n=6)of injection precision were between 0.27%-1.33%.The above results all met the inspection requirements.Conclusion:The two methods have high sensitivity,excellent specificity,good separation and simple pre-processing,which can characterize the contents of trace nitrite and nitrate in pharmaceutical lactose,and also provides new ideas and references for pre-risk study of other pharmaceutical excipients.