LC-MS/MS法测定发泡塑料餐具中5种荧光增白剂

Determination of Five Fluorescent Whitening Agents in Foam Plastic Tableware by High Performance Liquid Chromatography Tandem Mass Spectrometry

建立了高效液相色谱-串联三重四极杆质谱法（HPLC-MS/MS）同时测定发泡塑料餐具中5种荧光增白剂（FWA135、FWA184、FWA367、FWA368、FWA393）的方法。样品以三氯甲烷溶解提取，加入甲醇使基质沉淀，提取液氮吹浓缩，使用PHENOMENEX KINETEX C18色谱柱，0.1%甲酸甲醇-0.1%甲酸水为流动相进行梯度洗脱分离，采用串联质谱ESI正模式电离，多反应监测（MRM）模式检测，以保留时间及离子对比较定性，外标法定量。结果表明，5种荧光增白剂在0.5~50 μg/L范围内线性关系良好，相关系数大于0.995，仪器检出限（S/N=3）为0.1~0.5 μg/L，方法定量限（S/N=10）为0.4~2.0 μg/kg，添加水平为2、8、200 μg/kg时，样品的回收率在86.4~98.4%之间，相对标准偏差（RSD，n=6）小于3.9~8.1%。该法前处理简单、回收率高、精密度好，适用于发泡塑料餐具中5种荧光增白剂的测定。

A simple and sensitive method has been developed for the simultaneous determination of five fluorescent whitening agents （FWA135, FWA184, FWA367, FWA368 and FWA393） in foam plastic tableware using high performance liquid chromatography tandem mass spectrometry （HPLC-MS/MS）. The samples were extracted with trichloromethane, and the polymer in the extracts were precipitated by adding methanol. The separation of five FWAs was carried out on a Phenomenex kinetex C18 column （2.1 mm×100 mm, 2.6 μm） by gradient elution with 0.1% formic acid methanol and 0.1% formic acid as mobile phase. Electrospray ionization mass was operated in the positive mode （ESI＋） using multiple reaction monitoring （MRM） for the qualitative and quantitative analysis of five FWAby retention time and ion ratio. The result indicated that the linear correlation coefficients （r〉0.995） of five FWAs were obtained with the linear relationship between 0.5 to 50 μg/L. The limits of detection （ILOD, S/N=3） were ranged from 0.1 μg/L to 0.5 μg/L, and the limits of qualification of the method （MLOQ, S/N=10） were varied from 0.4 μg/kg to 2.0 μg/kg. The recoveries of five FWAs from spiked samples at the spiking levels of 2 μg/kg, 8μg/kg and 200 μg/kg were between 86.4% and 98.4% with RSD （n=6） less than 3.9% to 8.1%. The method was simple and precise for the determination of five FWAs in foam plastic tableware.