高效液相色谱-荧光检测法测定食品接触材料塑料制品中荧光增白剂

建立了同时测定食品接触材料塑料制品(食品包装袋)中荧光增白剂的高效液相色谱-荧光检测法。样品用20 mL三氯甲烷作提取剂,超声提取30 min,提取温度为40 ℃,用高效液相色谱进行定性定量分析。采用Eclipse XDB-C18(250 mm×4.6 mm, 5 μm)为分析柱,以5 mmol/L乙酸铵溶液和乙腈为流动相,梯度洗脱,荧光激发波长为350 nm,发射波长为430 nm。结果显示,4种荧光增白剂4,4′-双［2-(邻氰苯基)乙烯基］苯(1,4-bis(4-cyanostyryl)benzene, C.I. 199)、1,4-双(2-苯并恶唑)萘(1,4-bis (2-benzoxazolyl)naphthalene, C.I. 367)、4,4′-双(2-甲氧苯乙烯基)联苯(4,4′-bis(2-methoxystyryl)biphenyl, C.I. 378)和2,5-双(5-叔丁基-2-苯并恶唑基)噻吩(2,5-thiophenediylbis (5-tert-butyl-1,3-benzoxazole), C.I. 184)可以较好地分离;检出限(S/N=3)分别为0.3、0.1、0.05、0.14 mg/L,定量限(S/N=10)分别为1.0、0.4、0.2、0.5 mg/L,回收率范围为78.9%～101.1%,相对标准偏差小于10%,线性关系良好。该法简便、结果准确、灵敏度高,能够满足进出口食品包装材料塑料制品中荧光增白剂的日常检测。

Determination of fluorescent whitening agents in plastic food contact materials by high performance liquid chromatography with fluorescence detector

A method for the determination of fluorescent whitening agents in plastic food contact materials by high performance liquid chromatography (HPLC) with fluorescence detector was developed. The samples were extracted with trichloromethane by sonication for 30 min at 40 ℃. The HPLC method was performed on a column of Eclipse XDB-C18 (250 mm×4.6 mm, 5 μm) by gradient elution using 5 mmol/L ammonium acetate and acetonitrile as the mobile phases, and detected by the fluorescence detector at an excitation wavelength of 350 nm and an emission wavelength of 430 nm. The experimental results indicated that the four fluorescent whitening agents were separated well. The limits of detection (LOD) (S/N=3) were 0.3, 0.1, 0.05, 0.14 mg/L, and the limits of quantification (LOQ) (S/N=10) were 1.0, 0.4, 0.2, 0.5 mg/L for 1,4-bis(4-cyanostyryl)benzene (C.I. 199), 1,4-bis(2-benzoxazolyl)naphthalene (C.I. 367), 4,4′-bis(2-methoxystyryl)biphenyl (C.I. 378) and 2,5-thiophenediylbis (5-tert-butyl-1,3-benzoxazole) (C.I. 184), respectively. Good linearities with correlation coefficients (r2) not less than 0.991 were obtained. The proposed method is simple, accurate, sensitive and can meet the requirements of the routine determination of fluorescent whitening agents in entry-exit products.