이지현 (KIST)

이재익 (KIST)

이지현 (KIST)

강민식 (KIST)

이민규 (KIST)

김민주 (KIST)

차상원 (동국대학교)

오한빈 (서강대학교)

이재익 (KIST)

Anabolic steroid esters are esterified forms of anabolic-androgenic steroids (AAS) that increase lipophilicity and prolong pharmacological effects by slowing absorption into systemic circulation. Since these esters are not produced endogenously, their detection in blood provides unequivocal evidence of exogenous steroid administration. Dried blood spot (DBS) is a minimally invasive sample matrix with advantages in transportation and storage. In addition, the drying process suppresses enzymatic activity, thereby improving the stability of steroid esters. However, the limited sample volume in DBS samples and the low minimum required performance levels (MRPL) established by the World Anti-Doping Agency (WADA) for steroid esters (1-2 ng/mL) require a highly sensitive analytical method. Many current analytical methods have used derivatization method to improve analytical sensitivity. However, derivatization increases sample preparation time and complexity and reduces recovery and reproducibility.
In this study, we developed an LC-ESI-MS/MS-based method for the simultaneous analysis of steroid esters in DBS samples without derivatization. Analytical sensitivity was improved through the optimization of mobile phase composition, extraction conditions, and SPE-based sample clean-up procedures. The developed method enabled the detection of both short-chain and long-chain steroid esters.

This study was supported by an intramural grant from Korea Institute of Science and Technology (No. 26V0061).​