Aguilera R, Chapman T E, Catlin D H
UCLA Olympic Analytical Laboratory, Department of Molecular and Medical Pharmacology, University of California at Los Angeles, 2122 Granville Avenue, Los Angeles, CA 90025-6106, USA.
Rapid Commun Mass Spectrom. 2000;14(23):2294-9. doi: 10.1002/1097-0231(20001215)14:23<2294::AID-RCM165>3.0.CO;2-L.
A gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) method is described and validated for measurement of delta(13)C values of the acetate derivatives of urinary etiocholanolone and androsterone. The analysis was performed with only 2 mL of urine. The sample preparation consisted of deconjugation with beta-glucuronidase, solid phase extraction, and derivatization with acetic anhydride and pyridine. The within-assay precision of two quality control (QC) urine samples ranged from 0.5 to 2.1 CV%. The between-assay precision in the same QC urines ranged from 1.7 to 3.4 CV%. Administration of testosterone enanthate to a subject resulted in a 6 per thousand decrease in delta(13)C values from -25 per thousand (baseline) to -31 per thousand. Two weeks after testosterone administration was discontinued, the delta(13)C values remained abnormally low while the urine testosterone/epitestosterone (T/E) ratio returned to less than 6. This relatively simple method is useful for rapidly screening a large number of urine samples, including those with T/E <6.
描述并验证了一种气相色谱/燃烧/同位素比率质谱法（GC/C/IRMS），用于测定尿中表雄酮和雄酮乙酸酯衍生物的δ(13)C值。仅用2 mL尿液进行分析。样品制备包括用β-葡萄糖醛酸酶进行去结合、固相萃取以及用乙酸酐和吡啶进行衍生化。两个质量控制（QC）尿液样本的批内精密度范围为0.5%至2.1%变异系数（CV%）。相同QC尿液的批间精密度范围为1.7%至3.4% CV%。给一名受试者注射庚酸睾酮后，δ(13)C值从-25‰（基线）下降了6‰至-31‰。停用睾酮注射两周后，δ(13)C值仍异常低，而尿睾酮/表睾酮（T/E）比值恢复到小于6。这种相对简单的方法对于快速筛查大量尿液样本很有用，包括那些T/E <6的样本。
