超高效液相色谱-四极杆飞行时间串联质谱法同时分析奶粉中9种雌激素

Simultaneous Analysis of Nine Estrogens in Milk Powder with Ultra Performance Liquid Chromatography Coupled Quadrupole Time-of-Flight Mass Spectrometry

建立了奶粉中9种雌激素(雌三醇、β-雌二醇、α-雌二醇、马烯雌甾酮、17α-乙炔雌二醇、雌酮、己烯雌酚、己二烯雌酚、己烷雌酚)的超高效液相色谱-四极杆飞行时间串联质谱(UPLC-Q-TOF-MS)分析方法。样品用水溶解,乙腈超声提取雌激素,正己烷除脂,NH2柱净化,经Waters ACQUITY UPLC HSS T3色谱柱(100 mm×2.1 mm×1.8μm)分离,采用电喷雾离子源(ESI)负离子模式,对9种雌激素进行Q-TOF分析。分析时间13 min,线性范围为0.001～0.5 mg/L;检出限(S/N=3)为0.11～0.30μg/kg,定量限(S/N=10)为0.37～1.0μg/kg。考察了对9种雌激素精确质量数的测定能力和用基质内标法定量的回收率和精密度。9种雌激素的测定质量数与理论值误差在-1.0～0.9 mDa之间。在添加水平分别为1,2,10和100μg/kg时,平均回收率为61%～137%,RSD为1.0%～22.6%。采用本方法对市售的7种奶粉进行检测,未发现上述9种雌激素。

A rapid,sensitive and specific method has been developed for the simultaneous analysis of 9 estrogens including estradiol,β-estradiol,α-estradiol, equilin,17α-ethinylestradiol,estrone,diethylstilbestrol,dienestrol and hexestrol using ultra-performance liquid chromatography coupled quadrupole time-of-flight mass spectrometry（UPLC-Q-TOF-MS）with electrospray ionization（ESI） in negative mode. The milk powder was dissolved in water,the estrogens were extracted with acetonitrile using ultra-sonication and the lipids in extract solution were removed by n-hexane liquid-liquid extraction.Then the estrogens were purified by the NH2 solid phase extraction cartridge,separated on a Waters ACQUITY UPLC HSS T3 column （100 mm×2.1 mm×1.8 μm） and analyzed qualitatively and quantitatively by UPLC-Q-TOF in MS and MSe mode.The overall analysis time of the method was 13 min and the linear range was 0.001 to 0.5 mg/L.The limits of detection（LOD） for the compounds were from 0.11 to 0.30 μg/kg and the limits of quantification（LOQ） were in the range of 0.37-1.0 μg/kg.The mass errors between theoretical and experimental masses obtained for deprotonated molecules of 9 estrogens and internal standard （β-estradiol-d3） were between-1.0 and 0.9 mDa.At the spiked levels of 1,2,10,100 μg/kg,the average recoveries were 61%-137% with the relative standard deviations of 1.0%-22.6%.The results showed that this method is suitable to the multi-residue detection of estrogens in milk powder.It has been applied to the analysis of seven real milk powder samples,and the target estrogens were not found.