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Stability studies of testosterone and epitestosterone glucuronides in urine.
Rapid Commun Mass Spectrom. 2006; 20(5):858-64.RC

Abstract

The stability of testosterone glucuronide (TG), epitestosterone glucuronide (EG) and the T/E ratio in urine has been studied. Samples were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Urine samples were submitted to a solid-liquid cleanup followed by extraction of unconjugated testosterone (T) and epitestosterone (E) with tert-butyl methyl ether (free fraction). The remaining aqueous phase was hydrolyzed with beta-glucuronidase and extracted at alkaline pH with n-pentane. Analytes were analyzed by GC/MS as their enol-trimethylsilyl (TMS) derivatives. The urine for stability testing was obtained from an excretion study after the administration of T to healthy volunteers. The homogeneity of the sample was verified before starting the stability study. The stability of TG and EG was evaluated at different storage conditions. For long-term stability testing, analyte concentration in urine stored at 4 degrees C and -20 degrees C was determined at different time intervals for 22 months. For short-term stability testing, analyte concentration was evaluated in urine stored at 37 degrees C for 3 and 7 days. The effect of repeated freezing (at -20 degrees C) and thawing (at room temperature) was studied for up to three cycles. Data obtained in this work demonstrated the stability of TG, EG and the T/E ratio in sterilized urine samples stored at 4 and -20 degrees C for 22 months and after going through repeated freeze/thaw cycles. Decreases in concentration were observed after 7 days of storage at 37 degrees C due to the partial cleavage of the glucuronide conjugates; however, the T/E ratio was not affected. These results show the feasibility of preparing reference materials containing TG and EG to be used for quality control purposes.

Authors+Show Affiliations

Unitat de Farmacologia, Institut Municipal d'Investigació Mèdica, Barcelona, Spain.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Validation Study

Language

eng

PubMed ID

16470578

Citation

Jiménez, C, et al. "Stability Studies of Testosterone and Epitestosterone Glucuronides in Urine." Rapid Communications in Mass Spectrometry : RCM, vol. 20, no. 5, 2006, pp. 858-64.
Jiménez C, de la Torre R, Segura J, et al. Stability studies of testosterone and epitestosterone glucuronides in urine. Rapid Commun Mass Spectrom. 2006;20(5):858-64.
Jiménez, C., de la Torre, R., Segura, J., & Ventura, R. (2006). Stability studies of testosterone and epitestosterone glucuronides in urine. Rapid Communications in Mass Spectrometry : RCM, 20(5), 858-64.
Jiménez C, et al. Stability Studies of Testosterone and Epitestosterone Glucuronides in Urine. Rapid Commun Mass Spectrom. 2006;20(5):858-64. PubMed PMID: 16470578.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Stability studies of testosterone and epitestosterone glucuronides in urine. AU - Jiménez,C, AU - de la Torre,R, AU - Segura,J, AU - Ventura,R, PY - 2006/2/14/pubmed PY - 2006/4/7/medline PY - 2006/2/14/entrez SP - 858 EP - 64 JF - Rapid communications in mass spectrometry : RCM JO - Rapid Commun. Mass Spectrom. VL - 20 IS - 5 N2 - The stability of testosterone glucuronide (TG), epitestosterone glucuronide (EG) and the T/E ratio in urine has been studied. Samples were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Urine samples were submitted to a solid-liquid cleanup followed by extraction of unconjugated testosterone (T) and epitestosterone (E) with tert-butyl methyl ether (free fraction). The remaining aqueous phase was hydrolyzed with beta-glucuronidase and extracted at alkaline pH with n-pentane. Analytes were analyzed by GC/MS as their enol-trimethylsilyl (TMS) derivatives. The urine for stability testing was obtained from an excretion study after the administration of T to healthy volunteers. The homogeneity of the sample was verified before starting the stability study. The stability of TG and EG was evaluated at different storage conditions. For long-term stability testing, analyte concentration in urine stored at 4 degrees C and -20 degrees C was determined at different time intervals for 22 months. For short-term stability testing, analyte concentration was evaluated in urine stored at 37 degrees C for 3 and 7 days. The effect of repeated freezing (at -20 degrees C) and thawing (at room temperature) was studied for up to three cycles. Data obtained in this work demonstrated the stability of TG, EG and the T/E ratio in sterilized urine samples stored at 4 and -20 degrees C for 22 months and after going through repeated freeze/thaw cycles. Decreases in concentration were observed after 7 days of storage at 37 degrees C due to the partial cleavage of the glucuronide conjugates; however, the T/E ratio was not affected. These results show the feasibility of preparing reference materials containing TG and EG to be used for quality control purposes. SN - 0951-4198 UR - https://www.unboundmedicine.com/medline/citation/16470578/Stability_studies_of_testosterone_and_epitestosterone_glucuronides_in_urine_ L2 - https://doi.org/10.1002/rcm.2387 DB - PRIME DP - Unbound Medicine ER -