Determination of Cr(VI) concentration in diluted samples based on the paper test strip method

摘要

At present, there are many methods for Cr(VI) concentration determination in diluted samples,nhowever, these methods have their own inherent drawbacks, such as long response time,ncomplicated pretreatment, expensive equipment etc. In this paper, a paper-based test strip methodnspecific for determination of diluted Cr(VI) samples was developed. In this method, Aliquat 336, asnan anion exchanger was loaded into filter paper to form a test strip. This test strip was used to pre-nconcentrate Cr(VI) when contacting with the diluted Cr(VI)-containing solution. The Cr(VI)-containingntest strip was then immersed into a diphenylcarbazide (DPC) solution (a color forming solution), andnthe color intensity was correlated to the Cr(VI) concentration. The detection range of the presentnmethod was found to be 0.02–1.50mg/L. The results also showed that the method gave a highnselectivity for Cr(VI) in the diluted samples to be tested. The method was applied to synthesizednsamples and the results, which were compared to those from a reference method, showed thatnthe developed method is an effective, reliable way for Cr(VI) determination in diluted samples.