Developing a continuous flow-square wave voltammetry method for determination of atrazine in soil solutions using the hanging mercury drop electrode

Luciana B O Dos Santos,Gilberto Abate,Jorge C Masini

doi:10.1590/s0103-50532006000100005

Luciana B O Dos Santos, Gilberto Abate + Show 1 more

Open Access

https://doi.org/10.1590/s0103-50532006000100005

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Abstract

This work describes the development of a Continuous Flow-Square Wave Voltammetry method for determination of atrazine using the hanging mercury drop electrode. The best signal to noise ratio was obtained at the square wave frequency of 350 Hz and flow rate of 0.47 mL min-1. Under these conditions, the analytical curve obtained in 0.010 mol L-1 CaCl2 soil extracts in presence of 40 mmol L-1 BR buffer and 0.25 mol L-1 NaNO3 was linear for atrazine concentrations between 0.10 and 2.0 µg mL-1, with detection and quantification limits of 0.030 and 0.10 µg mL-1, respectively. The proposed method increased the analytical throughput in comparison with the batch methodology, allowing a sampling frequency of 72 h-1 to be accomplished. Besides, the sample consumption is significantly reduced, and only 341 µL are necessary for each analysis. The results obtained were similar to the ones obtained by HPLC, but the proposed method is faster and does not use organic solvents.

Highlights

The use of pesticides has increased in the world because of the increasing food production
The signal is given by the difference between these two currents. 21-23 This paper describes the development and optimization of a continuous flow-square wave voltammetry (CF-SWV) for determination of atrazine in soil solutions using the hanging mercury drop electrode
To improve centrifugation efficiency of soil suspensions, as well as to minimize cation exchange, the soil solutions were obtained in 0.010 mol L-1 CaCl2, as recommended by the OECD guideline 106 to perform adsorption-desorption of chemicals to soils using the batch equilibrium approach.[25]

Summary

Introduction

The use of pesticides has increased in the world because of the increasing food production. Electroanalytical techniques have been developed and applied for determination of herbicides in waters, soils and food.[14,15,16,17,18,19] De Souza et al.[14] determined paraquat in natural water and commercial tea samples using gold electrodes obtained from recordable compact disc using square wave voltammetry (SWV). 21-23 This paper describes the development and optimization of a continuous flow-square wave voltammetry (CF-SWV) for determination of atrazine in soil solutions using the hanging mercury drop electrode. Another set of standard solutions was prepared in the 40 mmol L-1 BR buffer (pH 2.0) in 0.25 mol L-1 NaNO using only deionized water

Procedure of analysis

Results and Discussion

Conclusions