Comprehensive determination and survey of 17 steroid hormones and their analoguesin milk using LC-ESI-MS/MS

摘要

A simple, accurate and simultaneous analysis method for 17 steroid hormones and their analogues in milk has been developed. A highly sensitive analysis was achieved using a LC-MS/MS system in which 0.1% formic acid (positive mode) and 0.028% ammonia (negative mode) were used for the mobile phase, and Wakopak* Ultra C18-2 as a HPLC column. Samples were extracted using a modified QuEChERS methodology, and was cleaned up with an Oasis* HLB cartridge. The developed method was validated in accordance withJapanese guidelines, and confirmed good trueness (ranging from 80.4% to 110.2%), RSDs of repeatability (under 11.9%), and within-laboratory reproducibility (under 18.6%). A survey of various milk samples revealed that almost all tested samples containedhydrocortisone (under the limits of quantification) and progesterone (under 25.1 ng/g), and that there were no traces of any other analytes. Moreover, the results showed that progesterone concentration tended to be distributed along with the amount of milkfat, with a correlation coefficient of over 0.88.