Renewable Energy and Environmental Protection Department, Advanced Materials Research Center (CIMAV), Chihuahua, Chihuahua, Mexico.
Anal Bioanal Chem. 2012 Sep;404(5):1589-95. doi: 10.1007/s00216-012-6198-x. Epub 2012 Jun 25.
A multisyringe flow-injection approach has been coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS) with UV photo-oxidation for dimethylarsinic (DMA), inorganic As and total As determination, depending on the pre-treatment given to the sample (extraction or digestion). The implementation of a UV lamp allows on-line photo-oxidation of DMA and the following arsenic detection, whereas a bypass leads the flow directly to the HG-AFS system, performing inorganic arsenic determination. DMA concentration is calculated by the difference of total inorganic arsenic and measurement of the photo-oxidation step. The detection limits for DMA and inorganic arsenic were 0.09 and 0.47 μg L(-1), respectively. The repeatability values accomplished were of 2.4 and 1.8%, whereas the injection frequencies were 24 and 28 injections per hour for DMA and inorganic arsenic, respectively. This method was validated by means of a solid reference material BCR-627 (muscle of tuna) with good agreement with the certified values. Satisfactory results for DMA and inorganic arsenic determination were obtained in several water matrices. The proposed method offers several advantages, such as increasing the sampling frequency, low detection limits and decreasing reagents and sample consumption, which leads to lower waste generation.
一种多注射器流动注射方法已与氢化物发生-原子荧光光谱法（HG-AFS）耦合，用于二甲砷酸（DMA）、无机砷和总砷的测定，具体取决于样品的预处理（提取或消化）。紫外线灯的实施允许在线氧化 DMA，并随后进行砷的检测，而旁路则使流动直接进入 HG-AFS 系统，进行无机砷的测定。DMA 浓度通过总无机砷的差值和光氧化步骤的测量来计算。DMA 和无机砷的检测限分别为 0.09 和 0.47 μg/L。重复性值分别为 2.4%和 1.8%，而 DMA 和无机砷的注射频率分别为每小时 24 次和 28 次。该方法通过固体参考物质 BCR-627（金枪鱼肌肉）进行了验证，与认证值吻合良好。该方法在多种水基质中对 DMA 和无机砷的测定均获得了令人满意的结果。该方法具有提高采样频率、降低检测限、减少试剂和样品消耗等优点，从而减少了废物的产生。
