Stability study of As(III), As(V), MMA and DMA by anion exchange chromatography and HG-AFS in wastewater samples
Stability study of As(III), As(V), MMA and DMA by anion exchange chromatography and HG-AFS in wastewater samples
复制标题
采用阴离子交换色谱和 HG-AFS 对废水样品中 As(III)、As(V)、MMA 和 DMA 进行稳定性研究
DOI：
10.1007/s00216-002-1492-7
复制
发表时间：
2002
影响因子：
4.3
通讯作者：
C. Cámara
中科院分区：
文献类型：
--
作者：
M. Segura;J. Muñoz;Y. Madrid;C. Cámara
研究了两种城市污水（原水和处理后的水样）中砷的形态[砷酸盐[As（V）]、甲基胂酸盐[MMA]、二甲基胂酸盐[DMA]和亚砷酸盐[As（III）]的稳定性。含有不同砷物质混合物的水样在三种不同温度下避光储存：+4 °C、+20 °C和+40 °C。采用高效液相色谱-氢化物发生-原子荧光光谱法测定砷的形态。直接从废水样品中优化了HPLC分离砷物种和AFS测定砷物种的实验条件。在阴离子交换柱上，以磷酸盐缓冲液（pH 6.0）为移动的相，砷（III）、砷（V）、甲基丙烯酸甲酯（MMA）和二甲基丙烯酸甲酯（DMA）得到分离。在此条件下，4种形态的砷在10 min内即可分离。As（III）、DMA、MMA和As（V）的检出限分别为0.6、0.9、0.9和1.8 μg L-1。As（V）、MMA和DMA在两种城市污水样品中在3种不同温度下4个月内保持稳定，而As（III）在原污水样品中的浓度在储存2周后下降。一个更大的稳定性As（III）被发现在处理后的城市污水样品。作为（III）保持不变，在此基质中，在pH 7.27的研究期间，而在较低的pH值（1.6）的损失，检测到的As（III）后1个月的存储。结果表明，As（III）浓度随时间的减少伴随着As（V）浓度的增加。
The stability of arsenic species {arsenate [As(V)], monomethylarsonate [MMA], dimethylarsinate [DMA] and arsenite [As(III)]} in two types of urban wastewater samples (raw and treated) was evaluated. Water samples containing a mixture of the different arsenic species were stored in the absence of light at three different temperatures: +4 °C, +20 °C and +40 °C. At regular time intervals, arsenic species were determined by high performance liquid chromatography (HPLC)-hydride generation (HG)-atomic fluorescence spectrometry (AFS). The experimental conditions for the separation of arsenic species by HPLC and their determination by AFS were directly optimised from wastewater samples. As(III), As(V), MMA and DMA were separated on an anion exchange column using phosphate buffer (pH 6.0) as the mobile phase. Under these conditions the four arsenic species were separated in less than 10 min. The detection limits were 0.6, 0.9, 0.9 and 1.8 µg L–1for As(III), DMA, MMA and As(V), respectively. As(V), MMA and DMA were found stable in the two types of urban wastewater samples over the 4-month period at the three different temperatures tested, while the concentration of As(III) in raw wastewater sample decreased after 2 weeks of storage. A greater stability of As(III) was found in the treated urban wastewater sample. As(III) remained unaltered in this matrix at pH 7.27 over the period studied, while at lower pH (1.6) losses of As(III) were detected after 1 month of storage. The results show that the decrease in As(III) concentration with time was accompanied by an increase in As(V) concentration.