Please use this identifier to cite or link to this item:
Title: Novel colorimetric method overcoming phosphorus interference during trace arsenic analysis in soil solution
Authors: Punamiya, Pravin 
Sarkar, Dibyendu 
Datta, Rupali K. 
Makris, Konstantinos C. 
Keywords: Aluminum;Arsenic;Ascorbic acid;Chromium;Copper;Iron;Lead;Malachite green;Nickel;Phosphorus;Silicon;Soil water;Zinc
Category: Earth and Related Environmental Sciences
Field: Natural Sciences
Issue Date: 2008
Publisher: Royal Society of Chemistry
Source: Analyst, 2008, Volume 133, Issue 2, Pages 191-196
Abstract: A sensitive (method detection limit, 2.0 μg As L-1) colorimetric determination of trace As(v) and As(iii) concentrations in the presence of soluble phosphorus (P) concentrations in soil/water extracts is presented. The proposed method modifies the malachite green method (MG) originally developed for P in soil and water. Our method relies upon the finding that As(iii) and As(v) do not develop the green color during P analysis using the MG method. When an optimum concentration of ascorbic acid (AA) is added to a sample containing up to 15 times P > As (μM) concentrations, the final sample absorbance due to P will be equal to that of As(v) molecules. The soluble As concentration can then be quantified by the concentration difference between the mixed oxyanion (As + P) absorbance (proposed method) and the MG method absorbance that measures only P. Our method is miniaturized using a 96-well microplate UV-VIS reader that utilizes minute reagent and sample volumes (120 and 200 μL sample-1, respectively), thus, minimizing waste and offering flexibility in the field. Our method was tested in a suite of As-contaminated soils that successfully measured both As and P in soil water extracts and total digests. Mean% As recoveries ranged between 84 and 117%, corroborating data obtained with high-resolution inductively-coupled plasma mass-spectrometry. The performance of the proposed colorimetric As method was unaffected by the presence of Cu, Zn, Pb, Ni, Fe, Al, Si, and Cr in both neutral and highly-acidic (ca. pH 2) soil extracts. Data from this study provide the proof of concept towards creating a field-deployable, portable As kit.
ISSN: 00032654
DOI: 10.1039/B714389C
Rights: © The Royal Society of Chemistry
Type: Article
Appears in Collections:Άρθρα/Articles

Show full item record


checked on May 12, 2019

Citations 50

Last Week
Last month
checked on Aug 13, 2019

Page view(s) 50

Last Week
Last month
checked on Aug 17, 2019

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.