Bartczak Dorota, Vincent Phil, Goenaga-Infante Heidi
†LGC Limited, Queens Road, Teddington, Middlesex TW11 0LY, United Kingdom.
‡NanoSight, a Malvern Instruments Limited, London Road, Amesbury, Wiltshire SP4 7RT, United Kingdom.
Anal Chem. 2015 Jun 2;87(11):5482-5. doi: 10.1021/acs.analchem.5b01052. Epub 2015 May 20.
We propose for the first time methodology for the determination of a number-based concentration of silica (SiO2) nanoparticles (NP) in biological serum using nanoparticle tracking analysis (NTA) as the online detector for asymmetric flow field-flow fractionation (AF4). The degree of selectivity offered by AF4 was found necessary to determine reliably number-based concentration of the measured NP in the complex matrix with a relative measurement error of 5.1% (as relative standard deviation, n = 3) and without chemical sample pretreatment. The simultaneous online coupling to other size and concentration detectors, such as multiangle light scattering (MALS) and ICPMS, for the measurement of the same NP suspension, was used to confirm the particle size determined with NTA and the equivalent particle number determined by AF4/NTA, respectively. The size- and number-based concentration data obtained by independent techniques were in a good agreement. The developed methodology can easily be extended to other types of particles or particle suspensions and other complex matrices provided that the particle size is above the limit of detection for NTA.
我们首次提出了一种方法，用于使用纳米颗粒跟踪分析（NTA）作为非对称流场流分馏（AF4）的在线检测器，测定生物血清中基于数量的二氧化硅（SiO₂）纳米颗粒（NP）浓度。发现AF4提供的选择性程度对于在复杂基质中可靠地测定被测NP的基于数量的浓度是必要的，相对测量误差为5.1%（作为相对标准偏差，n = 3），且无需化学样品预处理。同时将其与其他尺寸和浓度检测器（如多角度光散射（MALS）和ICPMS）在线联用，用于测量相同的NP悬浮液，分别确认用NTA测定的粒径和用AF4/NTA测定的等效颗粒数。通过独立技术获得的基于尺寸和数量的浓度数据吻合良好。只要颗粒尺寸高于NTA的检测限，所开发的方法就可以轻松扩展到其他类型的颗粒或颗粒悬浮液以及其他复杂基质。
