| Abstract: | A simple analytical method for the determination of hydrocortisone and progesterone in bovine, swine, and chicken muscle and eggs was developed. Hydrocortisone and progesterone were extracted with acetonitrile and subsequently cleaned-up using an Oasis® HLB mini-cartridge. The method was validated in accordance with Japanese guidelines and exhibited trueness from 86.6% to 104.3% and precision (relative standard deviations (RSDs) of repeatability and within reproducibility were under 8.7% and 11.7%, respectively). The method was applied to 103 bovine muscle, 137 swine muscle, 69 chicken muscle and 52 egg samples that were commercially available in Tokyo, Japan. The hydrocortisone concentration was 0.9–41.2 µg kg?1 in all bovine muscle samples, with an average of 7.7 µg kg?1 and a median of 6.2 µg kg?1. The progesterone concentration in 50 samples exceeded the limit of quantification (LOQ) and reached a maximum of 95.4 µg kg?1. Hydrocortisone was also detected in all swine muscle samples at concentrations of 2.0–56.0 µg kg?1. Its average and median concentrations amounted to 13.1 and 11.3 µg kg?1, respectively. Twenty-three samples contained progesterone levels surpassing the LOQ, with a maximum concentration of 107.0 µg kg?1. No chicken muscle samples contained any of the analytes. The progesterone concentration was 15.5–200.0 µg kg?1 in all egg samples, with an average of 95.4 µg kg?1 and a median of 90.5 µg kg?1. |
