左卡尼汀注射液中三甲胺分离提取及其离子色谱测定法研究

Separation and Detection of Trimethylamine in Levocarnitine Injection by Ion Chromatography

目的建立分离提取左卡尼汀注射液中三甲胺含量的方法,及采用离子色谱法对三甲胺进行检测研究。方法以L_(9)(3^(4))正交试验优化提取条件,采用0.25 mol·L^(-1)NaOH溶液创造碱性环境,40℃加热20 min,连接N^(2)流量为0.4 L·min^(-1),用0.1 mol·L^(-1)甲磺酸溶液吸收气体,有效实现左卡尼汀注射液中三甲胺的分离提取;采用DionexIonPac^(TM) CS12A(4.0 mm×250 mm)色谱柱,DionexIonPac^(TM) CG12A(4.0 mm×50 mm)保护柱,以17 mmol·L^(-1)甲磺酸溶液为淋洗液,流速0.5 mL·min^(-1),柱温30℃,电导检测。结果三甲胺在0.30~48.64μg·mL^(-1)内线性关系良好,相关系数为0.9993,检出限为0.012μg·mL^(-1)(S/N=3),定量限为0.3μg·mL^(-1)(S/N=10),精密度良好,溶液置于室温24 h或2~8℃48 h内稳定。平均加样回收率在97.33~100.82%内,相对标准偏差(RSD)为1.07%(n=9)。结论该方法能够有效提取分离左卡尼汀注射液中的三甲胺,离子色谱检测方法灵敏度高,回收率和重现性良好。

OBJECTIVE To establish a method for the separation,extraction and detection of trimethylamine in levocarnitine injection.METHODS The L_(9)(3^(4))orthogonal design was carried out in order to optimize the extraction method of trimethylamine in levocarnitine injection,which was finally established as follows:0.25 mol·L^(-1) NaOH solution was used to create an alkaline environment,heated at 40℃for 20 min,N_(2) flow of 0.4 L·min^(-1) was connected,and the gas was absorbed by 0.1 mol·L^(-1) methanesulfonic acid solution.DionexIonpACTM CS12A(4.0 mm×250 mm)column and DionexIonpACTM CG12A(4.0 mm×50 mm)protective column were adopted,using 17 mmol·L^(-1) methanesulfonic acid solution as eluent at a flow rate of 0.5 mL·min^(-1),the column temperature was maintained at 30℃,and conductivity detection was performed.RESULTS Trimethylamine showed good linear relationship within the range of 0.30-48.64μg·mL^(-1),the correlation coefficient was 0.9993,the detection limit was 0.012μg·mL^(-1)(S/N=3),the quantification limit was 0.3μg·mL^(-1)(S/N=10),the precision was good,and the solution was stable for 24 h at room temperature and 48 h at 2-8℃.The average recoveries were in the range of 97.33%-100.82%,and the RSD value was 1.07%(n=9).CONCLUSION The method can effectively extract and isolate trimethylamine in levocarnitine injection,and the ion chromatography detection method is proved to have high sensitivity,recovery and reproducibility.