Fontàs Clàudia, Vera Ruben, Batalla Anna, Kolev Spas D, Anticó Enriqueta
Department of Chemistry, University of Girona, 17071, Girona, Spain,
Environ Sci Pollut Res Int. 2014 Oct;21(20):11682-8. doi: 10.1007/s11356-014-2917-5. Epub 2014 May 7.
In the present work, a novel and simple detection system for As inorganic species contained in groundwater is presented. To reach the required detection limit, the proposed methodology is based on two steps: first is the transport and preconcentration of the inorganic arsenic species using a polymer inclusion membrane (PIM) system and second is the formation of a coloured complex, the absorbance of which is measured. Different parameters related to the membrane composition and the transport kinetics have been studied, and it was found that membranes made of polyvinyl chloride (PVC) as a polymer, and Aliquat 336 as a carrier, ensured efficient arsenic transport when the carrier content was at least 31 % (w/w). The implementation of the designed PIM in a special device that contained only 5 mL of the stripping solution (0.1 M NaCl) allowed As preconcentration from a 100-mL water sample, thus facilitating its detection with the colorimetric method. The new method developed here was validated, and its analytical figures of merit were determined, i.e. limit of detection of 4.5 μg L(-1) at 820 nm and a relative standard deviation within the range 8-10 %. Finally, the method was successfully applied to the analysis of different water samples from Catalonia region with naturally occurring As.
在本工作中，提出了一种用于检测地下水中砷无机物种的新型简单检测系统。为达到所需的检测限，所提出的方法基于两个步骤：首先是使用聚合物包容膜（PIM）系统对无机砷物种进行传输和预富集，其次是形成一种有色络合物，并测量其吸光度。研究了与膜组成和传输动力学相关的不同参数，发现以聚氯乙烯（PVC）为聚合物、Aliquat 336为载体制成的膜，当载体含量至少为31%（w/w）时可确保有效的砷传输。将设计好的PIM应用于仅含有5 mL洗脱液（0.1 M NaCl）的特殊装置中，可对100 mL水样中的砷进行预富集，从而便于用比色法进行检测。此处开发的新方法经过了验证，并确定了其分析性能指标，即在820 nm处的检测限为4.5 μg L⁻¹，相对标准偏差在8 - 10%范围内。最后，该方法成功应用于加泰罗尼亚地区含天然砷的不同水样的分析。
