Inorganic arsenic (As) speciation and behaviour were studied in the Gironde Estuary, a major European estuary in the south west of France. For the first time ever, the dynamic (potentially bioavailable) fraction of inorganic arsenite, As(III), and arsenate, As(V), were quantified in this estuary, using an antifouling gel-integrated gold microelectrode interrogated by square wave anodic stripping voltammetry (GIME-SWASV). The concentrations of dissolved As(III) and As(V) were determined by hydrid generation-flow injection-atomic absorption spectrometry (HG-FI-AAS) and inductively coupled plasma-mass spectrometry (ICP-MS) in collected samples following filtration through 0.2 μm, as well as 0.02 μm pore size filters. The concentrations of arsenite in the dynamic fraction, As(III)_dyn, ranged from 1.3 to 3.3 nM, contributing almost completely to the dissolved arsenite, As(III)_diss, which ranged between 0.9 and 3.1 nM in the 0.2 μm fraction, and between 1.2 and 3.7 nM in the 0.02 μm fraction. Concentrations of arsenate in the dynamic fraction, As(V)_dyn, ranged from 0.9 to 22.9 nM, and contributed to the dissolved arsenate, As(V)_diss, by 4–73% in the 0.2 μM fraction, and by 5–90% in the 0.02 μm fraction. The concentrations of As(V)_diss in the 0.2 μm fraction were between 14.5 and 36.2 nM, and between 15.2 and 34.9 nM in the 0.02 μm fraction.

The impact of this work is two-fold. Measurements of As species with different techniques allowed one to validate the on-board GIME voltammetric measurements. In addition, determination of As species in different fractions, as well as combining the obtained results with the conducted measurements of dissolved Mn and Fe, particulate suspended matters, and master physicochemical parameters (T, pH, O₂, redox E), helped to broaden the understanding of biotic and abiotic processes governing the distribution of arsenic, especially its potentially bioavailable forms, in the Gironde Estuary.

吉伦特河口是法国西南部的主要欧洲河口，研究了无机砷的形态和行为。在此河口，使用通过方波阳极溶出质询的防污凝胶集成金微电极，在该河口定量了无机砷（As（III）和砷酸砷（V））的动态（潜在生物利用度）分数伏安法（GIME-SWASV）。通过氢化物发生流动注射原子吸收光谱法（HG-FI-AAS）和电感耦合等离子体质谱法（ICP-MS）测定通过过滤后收集的样品中溶解的As（III）和As（V）的浓度。 0.2微米，以及0.02微米孔径的过滤器。动态分数As（III）_dyn中砷的浓度的范围从1.3到3.3 nM，几乎完全溶解了砷（As（III）_diss），其在0.2μm的范围内介于0.9和3.1 nM之间，在0.02μm的范围内介于1.2和3.7 nM之间。动态分数As（V）_dyn中的砷酸盐浓度范围为0.9至22.9 nM，并以0.2μM分数中的4-73％和5–90贡献了溶解的砷酸盐As（V）_diss。以0.02μm的百分比计。0.2μm馏分中的As（V）_diss浓度在14.5和36.2 nM之间，0.02μm馏分中的15.2和34.9 nM之间。

这项工作的影响是双重的。用不同的技术对砷物种的测量可以验证机载GIME伏安法测量结果。此外，测定不同馏分中的As种类，并将所得结果与进行的溶解的Mn和Fe，颗粒悬浮物和主要理化参数（T，pH，O ₂，氧化还原E）的测量相结合，有助于拓宽了吉伦特河河口控制砷分布的生物和非生物过程的理解，尤其是其潜在的生物利用形式。