Diviš Pavel, Reichstädter Marek, Gao Yue, Leermakers Martine, Křikala Jakub
Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech Republic.
Analytical, Environmental and Geo-Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
Foods. 2020 Dec 12;9(12):1858. doi: 10.3390/foods9121858.
The analysis of mercury in food presents a challenge for analytical chemists. Sample pre-treatment and the preconcentration of mercury prior to measurement are required, even when highly sensitive analytical methods are used. In this work, the Diffusive Gradients in Thin Films technique (DGT), combined with thermal decomposition gold amalgamation atomic absorption spectrometry (TDA-AAS), was investigated for the determination of the total dissolved mercury in fish sauces. Moreover, a new type of binding gel with Purolite S924 resin was used in DGT. Linearity assays for DGT provided determination coefficients around 0.995. Repeatability tests showed a relative standard deviation of less than 10%. pH values in the range of 3-6, as well as NaCl concentrations up to 50 g·L, did not affect the performance of DGT. The effective diffusion coefficient of mercury in five-fold diluted fish sauce was determined to be (3.42 ± 0.23)·10 cm·s. Based on the 24 h deployment time of DGT, the limit of detection (LOD) for the investigated method was 0.071 µg·L. The proposed method, which combines DGT and TDA-AAS, allows for the analysis of fish sauces with mercury concentrations below the LOD of TDA-AAS, and significantly reduces the wear and corrosion of the TDA-AAS components.
食品中汞的分析对分析化学家来说是一项挑战。即使使用高灵敏度的分析方法，在测量之前也需要进行样品预处理和汞的预浓缩。在这项工作中，研究了薄膜扩散梯度技术（DGT）与热分解金汞齐化原子吸收光谱法（TDA-AAS）相结合用于测定鱼露中总溶解汞的方法。此外，在DGT中使用了一种新型的含有普立特S924树脂的结合凝胶。DGT的线性分析提供的测定系数约为0.995。重复性测试表明相对标准偏差小于10%。pH值在3至6的范围内以及NaCl浓度高达50 g·L时，均不影响DGT的性能。测定出汞在五倍稀释鱼露中的有效扩散系数为(3.42 ± 0.23)·10 cm·s。基于DGT 24小时的部署时间，所研究方法的检测限（LOD）为0.071 µg·L。所提出的将DGT和TDA-AAS相结合的方法，能够分析汞浓度低于TDA-AAS检测限的鱼露，并且显著减少了TDA-AAS组件的磨损和腐蚀。
