类固醇类环境内分泌干扰物羟基衍生化研究

采用气相色谱-质谱联用技术(GC-MS),以N,O-双三甲基硅基三氟乙酰胺为衍生化试剂,系统研究了4种类固醇类环境内分泌干扰物雌酮(E1)、17β-雌二醇(E2)、雌三醇(E3)、17α-乙炔基雌二醇(EE2)的羟基衍生化行为,考察了BSTFA用量、衍生化温度和时间对类固醇类环境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,并对衍生化产物特征碎片离子的裂解机理进行了解释.结果表明:对于100 μL 0.01 g/L标准混合溶液,BSTFA的最佳用量为25 μL;衍生化过程不需要加热,常温下(20 ℃)下反应10 min就可取得最佳的衍生化效果;衍生化产物的稳定性较好,在-20 ℃下放置48 h,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的检出限为0.3 μg/L,EE2和E3的检出限为5 μg/L.

Hydroxyl Group Derivatization of Steroid Environmental Endocrine Disrupting Chemicals

The derivatization towards the hydroxyl groups of steroid environmental endocrine disrupting chemicals,such as estrone(E1),17β-estradiol(E2),estriol(E3) and 17α-ethynylestradoil( EE2),with A,O-bis (trimethylsilyl) trifluoroacetamide ( BSTFA ) as derivatization reagent followed by gas chromatography-mass spectrometry(GC-MS) was studied. The effects of the amount of BSTFA,derivatization temperature and time on the derivatization of target compounds,as well as the stability of steroid derivatives,calibration curves,instrumental quantification limits were investigated. The cleavage mechanism of steroid derivatives characteristic fragment ions was also interpreted. The results showed that better derivatization results were obtained when the amount of BSTFA was 25 μL for 100 μL steroids standard mix solution at 0.01 g/L;it is unnecessary to heating in the derivatization,better results were obtained when the steroids were derivatized with BSTFA at room temperature (20℃) for 10 min. The derivatives of target compounds were stable because their relative response factors(RRFs) had no observable change when deposited at -20℃ for 48 h. Under the optimal conditions,good linear correlation was obtained and the instrumental quantification limit was 0. 3μg/L for E1 and E2,while it was 5μg/L for EE2 and E3.