Huang W, Moody D E, Foltz R L, Walsh S L
Department of Pharmacology and Toxicology, University of Utah, Salt Lake City 84112, USA.
J Anal Toxicol. 1997 Jul-Aug;21(4):252-7. doi: 10.1093/jat/21.4.252.
Solid-phase extraction (SPE) and a one-step derivatization are combined with gas chromatography-negative ion chemical ionization-mass spectrometry to simplify a previously reported method for the determination of naltrexone and its metabolite, 6-beta-naltrexol, in human plasma. Deuterated isotopomers of naltrexone and 6-beta-naltrexol are used as internal standards. After SPE, the extracts are derivatized with pentafluoropropionic anhydride at room temperature to form predominantly the bispentafluoropropionyl derivative of naltrexone and the trispentafluoropropionyl derivative of 6-beta-naltrexol. The derivatized extracts are analyzed by monitoring ion currents at m/z 633 (naltrexone), m/z 636 (naltrexone-2H3), m/z 633 6-beta-naltrexol), and m/z 640 (6-beta-naltrexol-2H7). Control plasma samples containing 0.3, 3, or 30 ng/nl of each analyte were analyzed for precision and accuracy with the following results: intra-assay, the percentage of target concentrations were 107-113% for naltrexone and 107-120% for 6-beta-naltrexol, and the coefficients of variation (CVs) were 3.1-6.3% for naltrexone and 3.1-5.7% for 6-beta-naltrexol; interassay, the percentage of target concentrations were 103-110% for naltrexone and 110-113% for 6-beta-naltrexol, and the CVs were 6.1-9.1% for naltrexone and 5.9-9.1% for 6-beta-naltrexol. At the limit of quantitation (LOQ) of 0.1 ng/ml, both analytes quantified within 20% of the target concentration with CVs less than 17%. The extraction recoveries determined at 0.3 and 30 ng/ml were 79 and 80% for naltrexone and 76 and 75% for 6-beta-naltrexol. Bench-top stability tested with concentrations of 0.3 and 3.0 ng/ml did not decrease more than 10% from the zero-hour controls at 3, 6 and 24 h. Selectively was determined using plasma from six donors and none showed interfering peaks greater than 22% of the LOQ for naltrexone and 53% of the LOQ for 6-beta-naltrexol. Using this method, naltrexone and 6-beta-naltrexol were readily detected in plasma specimens collected 5.5 h after oral doses of 25 or 100 mg naltrexone. Following discontinuation of treatment, naltrexone was detected 30 h after the 100-mg dose, whereas 6-beta-naltrexol was detected 125 h after both the 25- and 100-mg doses.
固相萃取（SPE）和一步衍生化法与气相色谱 - 负离子化学电离 - 质谱联用，以简化先前报道的测定人血浆中纳曲酮及其代谢物6 - β - 纳曲醇的方法。纳曲酮和6 - β - 纳曲醇的氘代同位素异构体用作内标。经过固相萃取后，提取物在室温下用五氟丙酸酐进行衍生化，主要形成纳曲酮的双五氟丙酰衍生物和6 - β - 纳曲醇的三五氟丙酰衍生物。通过监测质荷比为633（纳曲酮）、636（纳曲酮 - 2H3）、633（6 - β - 纳曲醇）和640（6 - β - 纳曲醇 - 2H7）处的离子流对衍生化提取物进行分析。分析含每种分析物浓度为0.3、3或30 ng/nl的对照血浆样本的精密度和准确度，结果如下：批内，纳曲酮的目标浓度百分比为107 - 113%，6 - β - 纳曲醇为107 - 120%，纳曲酮的变异系数（CVs）为3.1 - 6.3%，6 - β - 纳曲醇为3.1 - 5.7%；批间，纳曲酮的目标浓度百分比为103 - 110%，6 - β - 纳曲醇为110 - 113%，纳曲酮的CVs为6.1 - 9.1%，6 - β - 纳曲醇为5.9 - 9.1%。在定量限（LOQ）为0.1 ng/ml时，两种分析物的定量结果在目标浓度±20%范围内，CVs小于17%。在0.3和30 ng/ml水平测定的萃取回收率，纳曲酮分别为79%和80%，6 - β - 纳曲醇分别为76%和75%。用浓度为0.3和3.0 ng/ml进行的台式稳定性测试表明，在3、6和24小时时，与零小时对照相比下降不超过10%。使用来自六个供体的血浆测定选择性，结果显示，对于纳曲酮，未出现大于定量限22%的干扰峰；对于6 - β - 纳曲醇，未出现大于定量限53%的干扰峰。采用该方法，在口服25或100 mg纳曲酮5.5小时后采集的血浆样本中很容易检测到纳曲酮和6 - β - 纳曲醇。停药后，在100 mg剂量给药30小时后检测到纳曲酮，而在25 mg和100 mg剂量给药125小时后均检测到6 - β - 纳曲醇。
