超高效液相色谱-串联质谱法检测婴儿米粉中11种有机磷阻燃剂

采用超高效液相色谱-串联质谱技术，建立婴儿米粉中11种有机磷阻燃剂的检测方法。样品用0.5%甲酸乙腈溶液超声提取，提取液经分散固相萃取吸附剂净化，聚四氟乙烯滤膜过滤后上机检测，5 mmol/L甲酸铵的水溶液和乙腈为流动相梯度洗脱，目标化合物在ACQUITY UPLC? BEH C₁₈ 色谱柱（100 mm×2.1 mm，1.7 μm）上实现分离，在电喷雾正离子扫描模式下进行多反应监测（MRM），外标法定量。通过优化色谱条件，11种有机磷阻燃剂均达到了基线分离。11种有机磷阻燃剂在0.5~100 μg/L（磷酸三辛酯0.05~10 μg/L）范围内线性关系良好，相关系数r均大于0.994。检出限（3S/N）为0.003~0.926 μg/kg，定量限（10S/N）为0.01~2.78 μg/kg。婴儿米粉中低、中、高3个添加浓度水平的加标回收率为63.2%~113.4%，相对标准偏差（n=6）均小于10%。运用建立的方法分析了4种婴儿米粉，磷酸三苯酯的检出率高达100%，其中一份米粉检出了磷酸三正丁酯和磷酸三（2-氯丙基）酯。该方法简单可靠、灵敏度高、重现性好，覆盖的有机磷阻燃剂种类多，适用于婴儿米粉中痕量有机磷阻燃剂的检测。

Determination of 11 Kinds of Organophosphorus Flame Retardants in Baby Rice Cereal by Ultra-high Performance Liquid Chromatography-tandem Mass Spectrometry

A method for the determination of 11 organophosphorus flame retardants in baby rice flour was established by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted by 0.5% formic acid acetonitrile solution by ultrasound. The extracted solution was purified by dispersive solid phase extraction packing and filtered by polytetrafluoroethylene membrane and detected by UPLC-MS/MS. Gradient elution was carried out with 5 mmol/L ammonium formate and acetonitrile. The target compounds were separated by ACQUITY UPLC? BEH C₁₈ column (100 mm×2.1 mm, 1.7 μm), and multiple response monitoring (MRM) was conducted in the positive electrospray ionization mode. The external standard method was used for quantification. By optimizing chromatographic conditions, all the 11 kinds of organophosphorus flame retardants achieved baseline separation. The 11 kinds of organophosphorus flame retardants had a good linear relationship in the range of 0.5~100 μg/L (Tris (2-ethylhexyl) phosphate 0.05~10 μg/L) with correlation coefficient r>0.994. The limits of detection (3S/N) were 0.003~0.926 μg/kg and the limits of quantitation (10S/N) were 0.01~2.78 μg/kg. The average recoveries at three spiked levels (low, medium and high) were 63.2%~113.4% with the relative standard deviations all less than 10% (n=6). Four kinds of baby rice cereal were analyzed by the established method and the detection rate of triphenyl phosphate (TPhP) was up to 100%. Tributyl phosphate (TnBP) and tris (2-chloroisopropyl) phosphate (TCPP) were also detected in one of the samples. The method could be used for the determination of trace organophosphorus flame retardants in baby rice flour cereal with accurate and reliable results.