Bhatt Jignesh, Jangid Arvind, Shetty Raghavendra, Shah Bhavin, Kambli Sandeep, Subbaiah Gunta, Singh Sadhana
Torrent Research Centre, Torrent Pharmaceuticals Limited, Village-Bhat, Gandhinagar-382428, Gujarat State, India.
Biomed Chromatogr. 2006 Aug;20(8):736-42. doi: 10.1002/bmc.589.
A simple and robust method for quantification of zolpidem in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS). Es-citalopram was used as an internal standard. Zolpidem and internal standard in plasma sample were extracted using solid-phase extraction cartridges (Oasis HLB, 1 cm3/30 mg). The samples were injected into a C8 reversed-phase column and the mobile phase used was acetonitrile-ammonium acetate (pH 4.6; 10 mm) (80:20, v/v) at a flow rate of 0.7 mL/min. Using MS/MS in the selected reaction-monitoring (SRM) mode, zolpidem and Es-citalopram were detected without any interference from human plasma matrix. Zolpidem produced a protonated precursor ion ([M+H]+) at m/z 308.1 and a corresponding product ion at m/z 235.1. The internal standard produced a protonated precursor ion ([M+H]+) at m/z 325.1 and a corresponding product ion at m/z 262.1. Detection of zolpidem in human plasma by the LC-ESI MS/MS method was accurate and precise with a quantification limit of 2.5 ng/mL. The proposed method was validated in the linear range 2.5-300 ng/mL. Reproducibility, recovery and stability of the method were evaluated. The method has been successfully applied to bioequivalence studies of zolpidem.
已建立一种使用液相色谱 - 电喷雾电离串联质谱法（LC - ESI MS/MS）定量测定人血浆中唑吡坦的简单且可靠的方法。艾司西酞普兰用作内标。血浆样品中的唑吡坦和内标使用固相萃取柱（Oasis HLB，1 cm³/30 mg）进行萃取。将样品注入C8反相柱，所用流动相为乙腈 - 醋酸铵（pH 4.6；10 mM）（80:20，v/v），流速为0.7 mL/min。在选择反应监测（SRM）模式下使用MS/MS，可检测到唑吡坦和艾司西酞普兰，且不受人血浆基质的任何干扰。唑吡坦产生质荷比为308.1的质子化前体离子（[M + H]+）和质荷比为235.1的相应产物离子。内标产生质荷比为325.1的质子化前体离子（[M + H]+）和质荷比为262.1的相应产物离子。采用LC - ESI MS/MS法检测人血浆中的唑吡坦准确且精密，定量限为2.5 ng/mL。该方法在2.5 - 300 ng/mL的线性范围内得到验证。评估了该方法的重现性（再现性）、回收率和稳定性。该方法已成功应用于唑吡坦的生物等效性研究。
