液相色谱-电喷雾电离质谱法检测地高辛人血浆药物浓度方法学的建立与考证

目的 建立适用于地高辛临床血药浓度监测的液相色谱-电喷雾电离质谱方法(LC-ESIMS)。方法 地高辛人血浆样本采用乙酸乙酯液液萃取后以LC-ESI-MS 方法进行分析。采用KromasilC₁₈柱(150 mm ×2.00 mm, 3.5 μm)分析柱;在乙腈和氯化铵的混合流动相的流动相系统中,进行梯度洗脱, 选择性负离子检测, 地高辛m z为815.40, 内标RgC₂ m/z 为819.00。结果 地高辛在0.05 ~ 10.0 ng/mL 浓度范围内线性关系良好(r=0.9989), 血浆内杂质不影响药物的检测, 方法回收率大于75 %, 批内、批间变异均小于15 %,冻融稳定性良好。结论 本研究所建立的LC-ESIMS测定方法操作简便、快速、灵敏, 准确, 重现性好, 所需血浆量少, 可用于地高辛临床血药浓度监测及临床药动学研究。

Development and validation of a liquid chromatographic electrospray ionization mass spectrometric method for the determination of digoxin in human plasma

AIM: To develop a sensitive and selective liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS)method for clinical identification and quantification of digoxin in human plasma.METHODS: The method was based on simple liquid-liquid extraction (LLE).A Kromasil C₁₈ column (150 mm ×2.00 mm, 3.5 μm)was used as the analytical column, while a mixture of acetonitrile and 500 μmol/L ammonium chloride was used as the mobile phase.MS detection was performed using a single quadrupole mass spectrometer in a negative selected ion monitoring (SIM)mode.The deprotonated molecules [M +Cl] (-)at m z 815.40 and 819.00 were used to quantify digoxin and RgC₂(internal standard, I. S.), respectively.RESULTS: The method was linear in the concentration range of 0.05-10.0 ng/mL.The determination of digoxin was not interfered by internal material.The method recovery of digoxin was higher than 75 %.The intra-day and inter-day precisions (RSD %)were within 15.0 %for the analyte, and the freeze-thaw stability of digoxin was excellent.CONCLUSION: While requiring less human plasma, the method was proved to be simple, accurate, sensitive, and had very good reproducibility.Thus, the proposed method enables unambiguous identification and quantification for the therapeutic drug monitoring and pharmacokinetic studies of digoxin.