反相高效液相色谱–荧光检测法测定面粉、淀粉中10种二苯乙烯类阴离子型荧光增白剂

Determination of Ten Kinds of Distyrene Styrene Fluorescent Whitening Agents in Flour and Starch by Reverse Phase High Performance Liquid Chromatography with Fluorescence Detector

摘要: 建立了反相高效液相色谱-荧光检测法检测面粉、淀粉中二苯乙烯类阴离子型荧光增白剂的方法。样品经过混合溶液(水 + 甲醇 + 三乙胺)超声提取后，以C18反相柱(Agilent XDB -C18 250 mm × 4.6 mm, 5 µm)进行分离，甲醇与四丁基溴化铵溶液为流动相，梯度洗脱，同时采用荧光检测器进行检测，有效分离了10种二苯乙烯类阴离子型荧光增白剂。在最佳实验条件下，FWA210、FWA220、FWA264、FWA353、FWA85、FWA113、FWA357、FWA5bm、FWA134、FWA71的线性范围在0~200 µg/L，相关系数均大于0.999，10种二苯乙烯类阴离子型荧光增白物质的方法检出限分别为0.020 mg/kg、0.020 mg/kg、0.020 mg/kg、0.020 mg/kg、0.020 mg/kg、0.020 mg/kg、0.010 mg/kg、0.010 mg/kg、0.005 mg/kg、0.005 mg/kg。FWA210、FWA220、FWA264、FWA353、FWA85、FWA113、FWA357、FWA5bm八种物质方法定量限为0.050 mg/kg，FWA134、FWA71两种物质方法定量限为0.020 mg/kg。添加水平在10~1000 µg/kg时，样品的回收率在80.2%~99.4%，样品的相对标准偏差(RSD, n = 6)在1.8%~6.7%间。该方法前处理简单、灵敏度高、回收率高、精密度好，适用于面粉、淀粉等粮食加工品中10种非法添加的二苯乙烯类阴离子型荧光增白剂的测定。

Abstract: A method for the determination of distyrene styrene fluorescent whitening agent in flour and starch by reverse phase high performance liquid chromatography with fluorescence detector was developed. The HPLC method was performed on column of Agilent XDB-C18 (250 mm × 4.6 mm, 5 µm) by gradient elution using methanol and 0.02 moL/L ammonium oxalate solution 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 ten kinds of distyrene styrene fluorescent whitening agents were separated well. Under optimized test conditions, the linear ranges of the method for FWA210, FWA220, FWA264, FWA353, FWA85, FWA113, FWA357, FWA5bm, FWA134, FWA71 were 0 to 200 μg/L, respectively. The correlation coefficients for all 10 target compounds were higher than 0.999. The limits of detection (LOD) (S/N = 3) were 0.020 mg/kg, 0.020 mg/kg, 0.020 mg/kg, 0.020 mg/kg, 0.020 mg/kg, 0.020 mg/kg, 0.010 mg/kg, 0.010 mg/kg, 0.005 mg/kg, 0.005 mg/kg for FWA210, FWA220, FWA264, FWA353, FWA85, FWA113, FWA357, FWA5bm, FWA134, FWA71, respectively. The limits of quantification (LOQ) (S/N = 10) were 0.050 mg/kg for FWA210, FWA220, FWA264, FWA353, FWA85, FWA113, FWA357, FWA5bm and 0.050 mg/kg for FWA134, FWA71, respectively. The recoveries rate were between 80.2%~99.4% for 5~1000 µg/kg additive levels and the relatively standard deviations (RSD, n = 6) were between 1.8%~6.7%. The proposed method was simple, accurate, high recovery rate, sensitive for determination of 10 kinds of illegally added distyrene styrene fluorescent whitening agents in grain processing products such as flour and starch.