超高效液相色谱-串联三重四极杆质谱法测定塑料食品接触材料中9种荧光增白剂

Determination of Nine Fluorescent Whiteners in Plastic Food Contact Materials by Ultra-high Performance Liquid Chromatography-Tandem Mass Spectrometry

建立同时测定塑料食品接触材料中FWA52、FWA135、FWA184、FWA185、FWA199、FWA367、FWA368、FWA378、FWA393荧光增白剂含量的超高效液相色谱-串联三重四极杆质谱检测方法。样品分别经三氯甲烷和甲醇在室温下2次超声提取30 min,合并提取液经氮吹至近干,甲醇复溶后,以乙酸铵溶液-乙腈作为流动相梯度洗脱,采用电喷雾离子源正离子多反应监测模式测定,外标法定量。结果表明:样品中9种荧光增白剂在0.5~1 000 ng/mL范围线性良好,相关系数均大于0.999,检出限为0.05~3.2 μg/kg,定量限为0.2~10 μg/kg,加标回收率范围为76.11%~106.55%,相对标准偏差(n=6)为1.97%~8.31%。该方法操作简便、准确、灵敏度高、回收率和重复性良好,适合于塑料接触制品中荧光增白剂的测定。

A method for simultaneous determination of nine fluorescent brighteners(FWA52, FWA135, FWA184, FWA185, FWA199, FWA367, FWA368, FWA378 and FWA393) in plastic food contact materials was developed by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Samples were extracted ultrasonically and sequentially with trichloromethane and methanol at room temperature for 30 minutes either, and the combined extract was blown to near dry by nitrogen and redissolved in methanol. For chromatographic separation, gradient elution was performed with ammonium acetate solution-acetonitrile as the mobile phase. Detection was performed using an electrospray ionization source in the positive ion(ESI+) model with multiple reaction monitoring(MRM), and quantification by external standard method. The results showed that the calibration curves for the nine fluorescent brighteners were linear in the range of 0.5–1 000 ng/m L with correlation coefficients greater than 0.999. The limit of detection(LOD) was 0.05–3.2 μg/kg, the limit of quantitative(LOQ) was 0.2–10 μg/kg, and the recoveries for spiked samples ranged from 76.11% to 106.55%, with relative standard deviations(RSDs, n = 6) of 1.97%–8.31%. The method proved to be simple, accurate, and sensitive, and had good recovery and repeatability. It could suitable for the determination of fluorescent whitening agents in plastic contact products.