Choi, MH Yoo, YS Chung, BC 2024-01-21T12:32:49Z 2024-01-21T12:32:49Z 2021-09-05 2001-04-25 0378-4347 https://pubs.kist.re.kr/handle/201004/140523 An efficient method for the determination of testosterone and pregnenolone in human nails using gas chromatography-mass spectrometry (GC-MS) with d(3)-testosterone as an internal standard is described. The method involves alkaline digestion and liquid-liquid extraction, with subsequent conversion to mixed pentafluoropenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive analysis in the selected-ion monitoring (SIM) mode. The limit of detection (LOD) and limit of quantification (LOQ) were lowered to 0.1 and 0.2 pg/g, respectively, when 100 mg of nail-clippings were used. The mean recoveries of testosterone and pregnenolone were 89.8 and 86.7%, respectively, while good overall precision (% C.V.; 4.5-9.5) and accuracy (% bias; 3.9-8.4) were demonstrated. Linearity as a correlation coefficient was 0.9913 (testosterone) and 0.9965 (pregnenolone). When applied to fingernail and toenail samples from seven healthy men and nine healthy women, testosterone and pregnenolone were positively detected in the concentration range of 0.24-5.80 ng/g. The levels of two steroids studied in the nails were found to be higher in the male subjects than in the female subjects, and except for the toenails of the females, the levels of testosterone were higher than those of pregnenolone. (C) 2001 Elsevier Science B.V. All rights reserved. English ELSEVIER SCIENCE BV ANABOLIC-STEROIDS GC-MS METABOLITES URINE DERIVATIZATION HAIR IDENTIFICATION TERBINAFINE DRUGS ABUSE Measurement of testosterone and pregnenolone in nails using gas chromatography-mass spectrometry Article 10.1016/S0378-4347(01)00038-X 1 JOURNAL OF CHROMATOGRAPHY B, v.754, no.2, pp.495 - 501 JOURNAL OF CHROMATOGRAPHY B 754 2 495 501 scie scopus 000168023800023 2-s2.0-0035946743 Biochemical Research Methods Chemistry, Analytical Biochemistry & Molecular Biology Chemistry Article ANABOLIC-STEROIDS GC-MS METABOLITES URINE DERIVATIZATION HAIR IDENTIFICATION TERBINAFINE DRUGS ABUSE testosterone pregnenolone