Determination Of Oxyanions Research Articles

A Gold Nanoparticle-Based Molecular Self-Assembled Colorimetric Chemosensor Array for Monitoring Multiple Organic Oxyanions

Determination of oxyanions is of paramount importance because of the essential role they play in metabolic processes involved in various aquatic environmental problems. In this investigation, a novel chemical sensor array has been developed by using gold nanoparticles modified with different chain lengths of aminothiols (AET-AuNPs) as sensing elements. The proposed sensor array provides a fingerprint-like response pattern originating from cross-reactive binding events and capable of targeting various anions, including the herbicide glyphosate. In addition, chemometric techniques, linear discrimination analysis (LDA) and the support vector machine (SVM) algorithm were employed for analyte classification and regression/prediction. The obtained sensor array demonstrates a remarkable ability to determine multiple oxyanions in both qualitative and quantitative analysis. The described methodology could be used as a simple, sensitive and fast routine analysis for oxyanions in both laboratory and field settings.

Eluent composition effect on ion chromatographic determination of oxyanions in solutions equilibrated with soils

Methods based on simultaneous determination of oxy-anions in soil extracts are needed for studies of competitive adsorption of oxyanions by soils. We studied the effect of NaHCO3/Na2CO3 and NaOH/Na2CO3 concentrations on ion chromatographic (IC) determination of PO 4 3− , AsO 4 3− , SeO 4 2− , SeO 3 2− , WO 4 2− , and MoO 4 2− in a 10-mM NaCl matrix equilibrated with soils by using a Dionex 2002i IC unit. The eluent, 6.0 mM NaOH+4.5 mM Na2CO3, resolved the 10 mM Cl− from the six oxyanions. Elution times for Cl−, SeO 3 2− , SO 4 2− , NO 3 − , SeO 4 2− , PO 4 3− , WO 4 2− , MoO 4 2− , and AsO 4 3− were 1.7, 2.7, 5.2, 6.1, 7.8, 10.5, 14.3, 17.7, and 21.2, respectively. The recovery of 0.2-mM oxyanion standards added to the soil solutions ranged from 93.0 to 106.8%, with coefficients of variation ranging from 0 to 14.3%. The detection limits of the oxyanions studied ranged from 0.3 μM for SeO 3 2− to 9.0 μM for AsO 4 3− .

Ion chromatographic method for determination of oxyanions in solutions equilibrated with soils

Abstract Methods based on simultaneous determination of oxyanions in soil solution are needed for studies of competitive adsorption of several oxyanions by soils. An accurate and precise ion Chromatographie (IC) method was developed for simultaneous determination of PO4 3‐, AsO4 3% SeO4 2‐, WO4 2‐, and MoO4 2‐ in solution equilibrated with soil. The water extract obtained was analyzed by a Dionex 2002i IC after filtering (0.45‐μm membrane filter). The IC unit was fitted with a guard column (AG‐3), a separator column (AS‐3), a 50‐μL injection loop, and a micromembrane suppressor system eluted with 12.5 mM H2SO4. A solution made 3.0 mM NaHCO3 + 6.0 mM Na2CO3 was used as an eluant, and conductivity was used as the mode of detection. The proposed method was tested by analyzing soil extracts obtained after equilibrating soils with a series of solutions containing mixtures of these oxyanions. Results showed that the elution times for PO4 3‐, AsO4 3‐, SeO4 2‐, WO4 2‐, and MoO4 2‐ were 1.8, 2.5, 4.1, 6.6, and 8.0...