金纳米粒子荧光增强法测定食品中痕量TBHQ

Determination of TBHQ Based on Fluorescence Enhancing of Gold Nanoparticles

建立食品中痕量TBHQ的金纳米粒子荧光增强测定法。以聚乙烯亚胺(PEI)作保护剂,用四羟甲基氯化磷(THPC)还原氯金酸,室温下合成一种稳定性好的金纳米粒子,该粒子溶液在380 nm激发下,在510 nm处有一强的荧光发射。试验发现,一定量的叔丁基对苯二酚(TBHQ)使金纳米在510 nm处荧光发射明显增强,由此建立了一种快速检测TBHQ的新方法。考察了体系pH、反应时间、温度等对TBHQ测定的影响,在最佳条件下,金纳米荧光强度与TBHQ在0.13～1.7 mg/kg浓度范围内呈良好的线性关系,相关系数R^2为0.995 0,检出限为0.12 mg/kg,相对标准偏差(RSD)为1.9%(n=11)。该方法用于饼干和方便面中TBHQ的检测,其加标回收率为98.5%～107.8%。

It was to develop a novel method for TBHQ determined in foods based on the fluorescence enhancement of gold(Au) nanoparticles(AuNPs). The AuNPs were synthesized in aqueous solution with polyethyleneimine as protective agent and THPC as reductant. At room-temperature, AuNPs colloids showed a considerable fluorescence emission at 510 nm under excitation of 380 nm. The experiment found that a certain amount of TBHQ enhanced the fluorescence of AuNPs at 510 nm, thus establishing a new simple and rapid method about detecting TBHQ. Different factors were studied, including the AuNPs concentration, buffer solution, pH, reaction time and reaction temperature. It was found that the TBHQ concentration has a better linear relationship with the AuNPs fluorescence intensity under the optimal conditions. The linear range was 0.13-1.7 mg/kg, the correlation coefficient R^2 was 0.995 0, the detection limit was 0.12 mg/kg, and the relative standard deviation was 1.9%(n=11). This method was used to detect the TBHQ in biscuits and instant noodles, and its recovery rate was 98.5%-107.8%.