Separate determination of arsenite and arsenate in groundwater samples by simple analytical methods

Abstract

We investigated the interaction of As(III) with As(III)-binding DNA aptamers (Ars-3). The binding of Ars-3 to As(III) was investigated using an Ars-3 sequence and a few control DNA sequences. As a result, we conclude that Ars-3 cannot bind As(III) and As(III) can adsorb onto gold nanoparticles with selectivity. However, the As(III) concentration could be determined by a simple As(III) analysis method using Ars-3, and we measured the As(III) and As(V) concentrations separately in As(III)/As(V) mixed samples in ultrapure water and groundwater using a simple analytical method for As(III) and As(V), respectively. As(III) in the sample was measured by a simple As(III) analytical method using DNA aptamers and gold nanoparticles, and As(V) in the sample was measured by a simple As(V) analysis method using cerium oxide nanoparticles and fluorescence-labeled DNA. We can measure As(III) and As(V) concentrations in ultrapure water and groundwater in the simple analytical method for As(III) and As(V), separately. HIGHLIGHTS We investigated the interaction between Ars-3 and As(III).; We determined As(III) and As(V) concentrations by simple analytical method for As(III) and As(V).; We hypothesized that the simple As(III) analysis method can quantify As(III) concentration by the adsorption of As(III) and ssDNA onto AuNPs.; We could determine the As(III) concentration and As(V) concentration in As(III)/As(V) mixed samples for each chemical species.;

Keywords

• arsenate
• arsenic species analysis
• arsenite
• groundwater
• simple analytical method