LC/MS/MS法测定癫痫患儿血浆中拉莫三嗪的浓度

Determination of Plasma Lamotrigine by Liquid Chromatography/Tandem Mass Spectrometry in Children with Epilepsy

目的建立一种快速、灵敏地测定癫痫患儿血浆中拉莫三嗪（lamotrigine，LTG）的LC／MS／MS方法。方法采用高效液相色谱串联质谱电喷雾检测（LC／MS／MS）法，色谱柱为Welch Materials XB—C18柱，流动相甲醇一水（95：5，V／V，含5mmol／L甲酸铵），流速0．3ml／min，柱温40℃，以碱化的醋酸乙酯：二氯甲烷（4：1）为提取剂。提取的样品经电喷雾离子源正离子化后，通过三重四级杆串联质谱仪，采用选择反应监测（SRM）对LTG（m／z256．0→145．0）和内标阿普唑仑（m／z309．3→281．1）进行测定。结果LTG血药浓度在0．05—25μg／ml范围内线性关系良好（r=0．9989），分析方法的最低检测限为5rig／ml，其高、中、低（12．5、1.25、0．125μg／ml）3个浓度的平均提取回收率分别为82．97％、80．68％和83．33％，日内（n=5）、日间（n=15）RSD均〈15％。结论本方法简单快捷、灵敏、准确、莺现性好。可用于癫痫患儿LTG的临床相药浓序精测和药动学研究．

Objective To establish a LC/MS/MS method for determination of plasma concentration of lamotrigine in patients with epilepsy. Method After extracted by acetoacetate and dichlormethane （4： 1, V/V）, lamotrigine was analyzed with a LC/MS/MS system using Welch Materials XB-C,s column at a column temperature of 40℃. The mobile phase was consisted of methanol and 5 mmol/L ammonium formate solution （30： 70, V/V）, pumped at a flow rate of 0. 3 ml/min. An Agilent 6410 triple quad mass spectrometer system equipped with an electrospray ionization ion-trap source was used as the detector and operated in the positive ion mode. Selection reaction monitoring （SRM） using the precursor to production combinations of m/z 256.0→145.0 and m/z 309.3→281. 1 was performed to detect lamotrigine and alprazolam, respectively. Results The calibration curves of lamotrigine were linear at a concentration range from 0.05 - 25 μg/ml （r =0. 998 9） with both of intra-day and inter-day 〈 15%. The average extraction recoveries were 82.97% （ 12.5 μg/ml） ,80.68% （ 1.25 μg/ml） and 83.33% （0. 125 μg/ml） respectively, with lowest detectable limit of 5 ng/ml. Conclusion The determination of lamotrigine concentrations in plasma is simple, accurate, and reliable. This method is suitable for the blood drug concentration monitoring of lamotrigine and pharmacokinetic study in patients with epilepsy.