National Centre for Food Science, Singapore Food Agency, 10 Perahu Road, Singapore, 718837, Singapore.
Veterinary Public Health Laboratory, Agri-Food and Veterinary Authority of Singapor, 10 Perahu Road, Singapore, 718837, Singapore.
Anal Bioanal Chem. 2020 Sep;412(22):5499-5512. doi: 10.1007/s00216-020-02770-x. Epub 2020 Jul 4.
Silicon dioxide (SiO) has been used as a food additive (E551) for decades. However, some safety concerns have been raised recently due to the detection of silica nanoparticles (SiO NPs) in a variety of foodstuffs and their unknown long-term health risk to humans. In order for risk assessment to be conducted, it is essential to establish a reliable, valid, and pragmatic method for analysis of SiO NPs in foods for estimation of exposure. This paper presents an effective approach for both size characterization and mass quantification of SiO NPs in commercial high-fat coffee creamer using asymmetric flow field-flow fractionation (AF4) coupled to inductively coupled plasma mass spectrometry (ICP-MS). SiO NPs from coffee creamer were well extracted after cleanup with hexane in a two-phase (hexane vs. water) aqueous environment. Size determination of SiO NPs was performed by on-line AF4-ICP-MS based on calibration with monodispersed standards. The dominant primary size of SiO NPs in the studied sample was 36.5 nm. The mass percentages of SiO NPs (vs. total SiO) were 18.6% for the dominant primary nano-silica particles by prechannel calibration and 35.7% for total SiO NPs (≤ 100 nm) by postchannel calibration, with recoveries of 89-96% for the former and 75% for the latter. The established approach was demonstrated to be efficient and practical for routine analysis of polydispersed SiO NPs with wide nano-size distribution in coffee creamer. This method may be extended to monitor the presence of SiO NPs in other similar complex food matrices. Graphical abstract.
二氧化硅（SiO）已被用作食品添加剂（E551）数十年。然而，由于在各种食品中检测到二氧化硅纳米颗粒（SiO NPs）及其对人类未知的长期健康风险，最近引起了一些安全关注。为了进行风险评估，必须建立一种可靠、有效和实用的方法，用于分析食品中的 SiO NPs，以估计暴露量。本文提出了一种有效方法，用于使用不对称流场流分离（AF4）结合电感耦合等离子体质谱（ICP-MS）对商业高脂肪咖啡奶精中的 SiO NPs 进行大小表征和质量定量。在两相（正己烷与水）水相环境中用正己烷进行清洗后，从咖啡奶精中很好地提取了 SiO NPs。通过在线 AF4-ICP-MS 基于与单分散标准品的校准进行 SiO NPs 的尺寸测定。在研究的样品中，SiO NPs 的主要初级粒径为 36.5nm。通过预通道校准，研究样品中主要初级纳米二氧化硅颗粒（占总 SiO）的质量百分比为 18.6%，通过后通道校准，总 SiO NPs（≤100nm）的质量百分比为 35.7%，前者的回收率为 89-96%，后者为 75%。所建立的方法被证明对于常规分析咖啡奶精中具有宽纳米尺寸分布的多分散 SiO NPs 是有效和实用的。该方法可扩展用于监测其他类似复杂食品基质中 SiO NPs 的存在。
