Environment and Health Department, Istituto Superiore di Sanità, 00161, Rome, Italy.
Anal Bioanal Chem. 2021 May;413(11):3027-3039. doi: 10.1007/s00216-021-03238-2. Epub 2021 Mar 16.
The suitability of asymmetric flow field-flow fractionation (AF4) coupled on-line to multi-angle light scattering (MALS) and UV diode array (UV-DAD) detectors was tested to simultaneously detect polystyrene nanoplastics (PS-NPs) and collect information about their size. A mixture of four sizes of PS-NPs at 20 nm, 60 nm, 100 nm and 200 nm was prepared by dilution with ultrapure deionized water and gentle mixing and was used as test sample for a polydisperse nanoplastic system. The AF4 method separated each single size of PS-NP mixture in a total time of 48 min by using 0.2% SDS as carrier solution. Then, the PS-NPs were sized and detected by following their MALS (90° scattering angle) and UV (215 nm) signals. Quality control (QC) performances as linearity, between-day repeatability, resolution factor, trueness/recovery, limit of detection (LoD) and selectivity were calculated, according to the ISO/TS 21362:2018. Method uncertainty was calculated following the ISO/TS 21748:2002 by summing between-day repeatability and trueness or recovery uncertainties. In-house validation results demonstrated good peak resolution and selectivity, R linearity of 0.998-0.999 in the range 50-1000 μg/mL, between-day repeatability of ca. 10%, trueness/recovery above 90% and LoD between 15 μg/mL (20 nm) and 33 μg/mL (200 nm). Expanded uncertainty was 16.1-17.9% on PS-NP size between 60 and 200 nm and 10.4-14.7% on PS-NP concentration between 100 and 1000 μg/mL. Compared to traditional single-technique analysis, this hyphenated method offers great promise for separating and analysing diverse populations of PS-NPs present in real matrices, which is critical for health and risk assessment studies and any regulatory action.
采用不对称流场流分离（AF4）与多角度光散射（MALS）和紫外二极管阵列（UV-DAD）在线联用的方法，同时检测聚苯乙烯纳米塑料（PS-NPs）并收集其尺寸信息。通过稀释超纯水并轻轻混合，制备了四种不同尺寸的 PS-NPs（20nm、60nm、100nm 和 200nm）混合物作为多分散纳米塑料系统的测试样品。在 0.2%SDS 作为载体溶液的情况下，AF4 方法在 48 分钟内分离了 PS-NP 混合物的每种单一尺寸。然后，通过跟踪 PS-NP 的 MALS（90°散射角）和 UV（215nm）信号对其进行尺寸检测。根据 ISO/TS 21362:2018，计算了线性度、日间重复性、分辨率因子、准确度/回收率、检测限（LoD）和选择性等质量控制（QC）性能。按照 ISO/TS 21748:2002 通过累加日间重复性和准确度或回收率不确定度计算了方法不确定度。内部验证结果表明，该方法具有良好的峰分辨率和选择性，在 50-1000μg/mL 范围内 R 线性度为 0.998-0.999，日间重复性约为 10%，准确度/回收率大于 90%，检测限为 15μg/mL（20nm）至 33μg/mL（200nm）。60nm 至 200nm 范围内 PS-NP 尺寸的扩展不确定度为 16.1-17.9%，100μg/mL 至 1000μg/mL 范围内 PS-NP 浓度的扩展不确定度为 10.4-14.7%。与传统的单一技术分析相比，这种联用方法为分离和分析真实基质中存在的不同 PS-NP 群体提供了巨大的潜力，这对于健康和风险评估研究以及任何监管行动至关重要。
