Garland W A, Muccino R R, Min B H, Cupano J, Fann W E
Clin Pharmacol Ther. 1979 Jun;25(6):844-56. doi: 10.1002/cpt1979256844.
A gas chromatography--mass spectrometry (GC-MS) method has been developed to measure amitriptyline and its metabolites nortriptyline, 10-hydroxyamitriptyline, and 10-hydroxynortriptyline in human plasma. Deuterated analogs of each compound were synthesized as internal standards. Isobutane was used as both gas chromatography (GC) carrier gas and chemical ionization (CI) reagent gas. In order to obtain compounds with satisfactory GC and mass spectrometry (MS) properties, the two alcohol metabolites were dehydrated without loss of label during sample preparation. Selective ion monitoring of the MH+ ions of the protio- and deuterio- compounds gave ion ratios which were converted to plasma concentrations using standard curves. For amitriptyline and nortriptyline, which are assayed using multiple deuterated analogs as internal standards, the curves are straight lines. For 10-hydroxyamitriptyline and 10-hydroxynortriptyline, which are assayed using monodeuterated analogs as internal standards, the curves are nonlinear and are analyzed using an iterative computer procedure. Assay sensitivity is 0.5 ng/ml for amitriptyline, nortriptyline, and 10-hydroxyamitriptyline and 1 ng/ml for 10-hydroxynortriptyline. Assay precision and accuracy in terms of percent error are both less than 5%. Following oral administration of a single 75-mg dose of amitriptyline to two subjects, the mean plasma levels of amitriptyline, nortriptyline, 10-hydroxyamitriptyline, conjugated 10-hydroxyamitriptyline, 10-hydroxynortriptyline, and conjugated 10-hydroxynortriptyline were 36, 8, 10, 66, 16, and 46 ng/ml, respectively, at 2 hr after dosing and 3, 4, 0.5, 1, 6, and 17 ng/ml, respectively, at 72 hr after dosing. Analyses of plasma samples from 12 subjects who had been receiving 50 mg amitriptyline therapy three times a day for an average +/- SD of 32 +/- 5 days gave a mean concentration of 81 +/- 40 ng/ml for amitriptyline, 71 +/- 57 ng/ml for nortriptyline, 12 +/- 5 ng/ml for 10-hydroxyamitriptyline, 91 +/- 30 ng/ml for conjugated 10-hydroxyamitriptyline, 82 +/- 27 ng/ml for 10-hydroxynortriptyline, and 176 +/- 64 ng/ml for conjugated 10-hydroxynortriptyline.
已开发出一种气相色谱 - 质谱联用（GC-MS）方法，用于测定人血浆中的阿米替林及其代谢产物去甲替林、10 - 羟基阿米替林和10 - 羟基去甲替林。合成了每种化合物的氘代类似物作为内标。异丁烷既用作气相色谱（GC）载气，又用作化学电离（CI）反应气。为了获得具有令人满意的气相色谱和质谱（MS）特性的化合物，在样品制备过程中，两种醇代谢产物进行了脱水处理且未损失标记。对质子化和氘代化合物的MH⁺离子进行选择性离子监测，得到离子比率，使用标准曲线将其转换为血浆浓度。对于使用多种氘代类似物作为内标的阿米替林和去甲替林，曲线为直线。对于使用单氘代类似物作为内标的10 - 羟基阿米替林和10 - 羟基去甲替林，曲线是非线性的，使用迭代计算机程序进行分析。阿米替林、去甲替林和10 - 羟基阿米替林的测定灵敏度为0.5 ng/ml，10 - 羟基去甲替林的测定灵敏度为1 ng/ml。以误差百分比表示的测定精密度和准确度均小于5%。对两名受试者口服单剂量75 mg阿米替林后，给药后2小时，阿米替林、去甲替林、10 - 羟基阿米替林、结合型10 - 羟基阿米替林、10 - 羟基去甲替林和结合型10 - 羟基去甲替林的平均血浆水平分别为36、8、10、66、16和46 ng/ml，给药后72小时分别为3、4、0.5、1、6和17 ng/ml。对12名平均接受32±5天每日三次每次50 mg阿米替林治疗的受试者的血浆样本分析显示，阿米替林的平均浓度为81±40 ng/ml，去甲替林为71±57 ng/ml，10 - 羟基阿米替林为12±5 ng/ml，结合型10 - 羟基阿米替林为91±30 ng/ml，10 - 羟基去甲替林为82±27 ng/ml，结合型10 - 羟基去甲替林为176±64 ng/ml。
