类固醇类内分泌干扰物羟基衍生化条件的优化

以N-甲基-N-三甲基硅基三氟乙酰胺(MSTFA)为衍生化试剂,采用气相色谱-质谱联用技术(GC-MS)系统研究了4种类固醇类内分泌干扰物雌酮(E1)、17β-雌二醇(E2)、雌三醇(E3)、17α-乙炔基雌二醇(EE2)的羟基衍生化,主要考察了MSTFA用量、衍生化温度、衍生化时间对类固醇类内分泌干扰物衍生化效果的影响以及衍生化产物的稳定性、标准曲线、仪器检出限等.结果表明:100μl浓度为0.01μg.μl-1的标准混合溶液,MSTFA的最佳用量为20μl;最佳衍生化条件为70℃下反应30min;衍生化产物的稳定性较好,在-20℃下放置48h,相对响应因子(RRF)基本没有降低;在优化的实验条件下,各待测物具有良好的线性相关性,E1和E2的仪器检出限为0.1pg.μl-1,EE2和E3的仪器检出限为1pg.μl-1.

OPTIMISATION OF DERIVATISATION CONDITIONS FOR STEROID ENDOCRINE DISRUPTING CHEMICALS

The derivatization of the hydroxyl groups in steroid endocrine disrupting chemicals,such as estrone (E1),17β-estradiol(E2),estriol(E3)and 17α-ethynylestradoil(EE2),with N-methyl-N-(trimethylsilyl)trifluoroacetamide(MSTFA)as derivatization reagent followed by gas chromatography-mass spectrometry(GCMS)was studied.The effects of the amount of MSTFA,derivatization temperature and time on the derivatization of target compounds,as well as the stability of steroid derivatives,calibration curves and instrumental quantification limits were systematically investigated.The results show that best derivatization results were obtained when the amount of MSTFA was 20μl for 100μl steroids standard mix solution at 0.01μg·μl~(-1) ; the optimal derivatization condition was reaction at 70℃ for 30min; The derivatives of target compounds were stable because their RRFs showed no observable change when kept at-20℃ for 48h.Under the optimal condition,good linear correlation was obtained and the instrumental quantification limit was 0.1 pg·μl~(-1) for E1 and E2,while it was 1pg·μl~(-1) for EE2 and E3.