Abstract

A new and simple methodology has been developed on the use of dynamic light scattering for sizing silica nanoparticles and detecting their presence or absence in several food samples, namely fruit juices and sweeteners. Size confirmation of four nanosilica standards (20, 50, 80 and 100 nm) was performed with an error percentage lower than 3.5% and low concentration levels (a few mg L⁻¹) were detected by dynamic light scattering, demonstrating the excellent sensitivity of this technique for characterizing these small nanoparticles present at low values. Moreover, no significant differences in size were observed in the concentration range assayed in this work. The applicability of this new approach has been successfully demonstrated in food items separately spiked with nanosilica of each size. No matrix effects were observed in the correlograms obtained by dynamic light scattering. The results showed that all of the samples contain a remarkable population of nanoparticles from an unknown source, increasing the interest of these findings.

摘要

已经开发出一种新的简单方法，该方法是使用动态光散射确定二氧化硅纳米颗粒的尺寸并检测几种食品样品（例如果汁和甜味剂）中是否存在纳米颗粒。进行了四种纳米二氧化硅标准品（20、50、80和100 nm）的尺寸确认，误差百分比低于3.5％，浓度水平较低（几毫克L ^-1通过动态光散射检测），证明了该技术对表征低浓度存在的这些小纳米粒子的出色灵敏度。此外，在这项工作中测定的浓度范围内，没有观察到大小上的显着差异。这种新方法的适用性已在分别掺入各种尺寸的纳米二氧化硅的食品中得到了成功证明。在通过动态光散射获得的相关图中未观察到基质效应。结果表明，所有样品均包含来自未知来源的大量纳米颗粒，这增加了对这些发现的兴趣。