Shiva Amir Houshang, Teasdale Peter R, Welsh David T, Bennett William W
Environmental Futures Research Institute, Griffith University, Gold Coast Campus, QLD 4215, Australia.
Environ Sci Process Impacts. 2017 May 24;19(5):742-751. doi: 10.1039/c6em00276e.
The performance of DGT-Chelex, DGT-Metsorb and DGT-MBL (Chelex-Metsorb mixed binding layer) with open and restricted diffusive layers for trace metal (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) and oxyanion (As, Mo, Sb, V) measurements, was evaluated in four natural waters with different pH (range 3.29-7.81). In moderately acidic (pH ≈ 5) and circumneutral (pH ≈ 6.3) waters, all three binding layers measured relatively similar concentrations of Al, while in more alkaline waters (pH ≈ 8) DGT-MBL measured higher concentrations than the other two binding layers. The measurements of DGT-Chelex and DGT-MBL for Co, Cu, Ni, Pb and Zn, and DGT-Metsorb and DGT-MBL for As, Sb and V were within 82-119% and not statistically different (p > 0.05) over the pH range 5-8. Mn measurements by DGT-Chelex and DGT-MBL were quite similar (95%) at pH 6.3, while DGT-MBL measured higher concentrations than DGT-Chelex at other pHs. The ratios of measured concentrations with different diffusive layers (C/C) were between 0.78 and 1.12 for all binding layers and no statistical differences (p > 0.05) were observed, except for Al at pH 7.81 and Cu at pH 6.28. DGT-MBL was comparable to DGT-Chelex for the measurement of most trace metals, and to DGT-Metsorb for the measurement of most oxyanions, over the pH range 5.05-7.81. Overall, DGT-MBL is superior to the other tested binding layers because it can simultaneously measure cations and anions, and accurately measure dissolved Al, across the greatest range of environmental conditions.
在pH值范围为3.29 - 7.81的四种天然水中，评估了带有开放和受限扩散层的DGT - Chelex、DGT - Metsorb和DGT - MBL（Chelex - Metsorb混合结合层）用于痕量金属（铝、镉、钴、铜、锰、镍、铅、锌）和含氧阴离子（砷、钼、锑、钒）测量的性能。在中等酸性（pH≈5）和中性（pH≈6.3）的水中，所有三种结合层测得的铝浓度相对相似，而在碱性更强的水中（pH≈8），DGT - MBL测得的浓度高于其他两种结合层。在pH值5 - 8范围内，DGT - Chelex和DGT - MBL对钴、铜、镍、铅和锌的测量值，以及DGT - Metsorb和DGT - MBL对砷、锑和钒的测量值在82% - 119%之间，且无统计学差异（p > 0.05）。在pH 6.3时，DGT - Chelex和DGT - MBL对锰的测量结果相当相似（95%），而在其他pH值下，DGT - MBL测得的浓度高于DGT - Chelex。对于所有结合层，不同扩散层测量浓度的比值（C/C）在0.78至1.12之间，除了在pH 7.81时的铝和pH 6.28时的铜，未观察到统计学差异（p > 0.05）。在pH值5.05 - 7.81范围内，对于大多数痕量金属的测量，DGT - MBL与DGT - Chelex相当，对于大多数含氧阴离子的测量，DGT - MBL与DGT - Metsorb相当。总体而言，DGT - MBL优于其他测试的结合层，因为它可以同时测量阳离子和阴离子，并且在最广泛的环境条件下准确测量溶解态铝。
