Provete Carolina S, Dalfior Bruna M, Mantovaneli Rafael, Carneiro Maria Tereza W D, Brandão Geisamanda P
Laboratory of Atomic Spectrometry (LEA), Chemistry Department, Federal University of Espírito Santo, Vitória, Espírito Santo 29075-910, Brazil.
ACS Omega. 2024 Nov 28;9(50):49229-49238. doi: 10.1021/acsomega.4c06144. eCollection 2024 Dec 17.
Mercury (Hg) determination in marine sediment is an analytical challenge due to the toxicity of this element even at low concentrations (up to 130 μg kg in marine sediments) and complex matrices. Therefore, it is necessary to use analytical techniques that have high sensitivity, selectivity, and low limits of quantification (LoQ). In this study, two methods that require sample treatment and one method with direct sampling were studied. The techniques studied were inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry with cold vapor generation (CV-ICP-OES), and atomic absorption spectrometry with thermodecomposition and amalgamation (TDA AAS) for Hg determination in marine sediment samples. Since ICP-MS has more studies in the literature, optimization with design of experiments was developed for CV-ICP-OES and TDA AAS. Although it was found to have low levels of instrumental LoQ for all three techniques, differences were found once the method LoQ was calculated. The calculation for method LoQ considers all analytical procedures executed, including sample treatment, which provides a 100-fold dilution for ICP-MS and CV-ICP-OES. The method LoQ obtained were 1.9, 165, and 0.35 μg kg for ICP-MS, CV-ICP-OES, and TDA AAS, respectively. Comparing marine sediment sample analyses, Hg concentrations had no statistical difference when determined by ICP-MS and TDA AAS. It was not possible to determine Hg in marine sediment samples by CV-ICP-OES due to the high method LoQ obtained (165 μg kg). Although ICP-MS has the advantage of being a multielemental technique, it is high-value equipment and needs a large volume of argon, which has a high cost in the market, and it requires sample treatment. On the other hand, TDA AAS-based spectrometer DMA-80 performs direct sampling, avoiding the pretreatment stage, and has a relatively lower cost, both in terms of initial investment and maintenance, while maintaining the high sensitivity, accuracy, and precision required for Hg determination on marine sediment samples.
由于汞（Hg）即使在低浓度下（海洋沉积物中高达130μg/kg）也具有毒性且基质复杂，因此测定海洋沉积物中的汞是一项分析挑战。所以，有必要使用具有高灵敏度、高选择性和低定量限（LoQ）的分析技术。在本研究中，对两种需要样品处理的方法和一种直接采样方法进行了研究。所研究的技术包括电感耦合等离子体质谱法（ICP-MS）、冷蒸气发生电感耦合等离子体发射光谱法（CV-ICP-OES）以及热分解汞齐化原子吸收光谱法（TDA AAS），用于测定海洋沉积物样品中的汞。由于ICP-MS在文献中有更多研究，因此针对CV-ICP-OES和TDA AAS开发了基于实验设计的优化方法。尽管发现所有这三种技术的仪器LoQ水平都较低，但计算方法LoQ时发现了差异。方法LoQ的计算考虑了所有执行的分析程序，包括样品处理，这对ICP-MS和CV-ICP-OES进行了100倍稀释。ICP-MS、CV-ICP-OES和TDA AAS获得的方法LoQ分别为1.9、165和0.35μg/kg。比较海洋沉积物样品分析结果，通过ICP-MS和TDA AAS测定时汞浓度无统计学差异。由于获得的方法LoQ较高（165μg/kg），无法通过CV-ICP-OES测定海洋沉积物样品中的汞。尽管ICP-MS具有多元素分析技术的优势，但它是高价值设备，需要大量氩气，市场成本高，且需要样品处理。另一方面，基于TDA AAS的DMA-80光谱仪可进行直接采样，避免了预处理阶段，并且在初始投资和维护方面成本相对较低，同时保持了测定海洋沉积物样品中汞所需的高灵敏度、准确性和精密度。
