An Alternative Spectrophotometric Determination of Carbaryl Insecticide Residues in Water Samples Using the Cerium-Catalyzed Belousov-Zhabotinsky Oscillating Reaction

Titikan Somboon,Supalax Srijaranai,Sira Sansuk,Yanawath Santaladchaiyakit

doi:10.21577/0103-5053.20190261

Abstract

An alternative approach for carbaryl determination based on the change in the oscillation period of the Belousov-Zhabotinsky (BZ) reaction under the addition of carbaryl is demonstrated. The oscillations were observed by spectrophotometric measurement at 320 nm, corresponding to the maximum absorption wavelength of cerium(IV) catalyst. The oscillation periods increase with the carbaryl concentrations, which can be discussed based on the Field-Koros-Noyes (FKN) mechanism. The increase of oscillation periods is proportional to the concentration of carbaryl in the range of 0.1-200 mg L-1 with the regression coefficient of 0.9938. The limits of detection and quantification were 0.044 and 0.147 mg L-1, respectively. The precisions in terms of intra-day and inter-day measurements were efficient with relative standard deviation (RSD) lower than 2.1%. Accuracy of carbaryl in different water samples was obtained with high recoveries in the range of 94-106% and also comparable to the results of high performance liquid chromatography (HPLC) analysis. The proposed method is precise, cost-effective and can be alternatively employed for the screening and determination of carbaryl residues in water samples.

Highlights

Carbaryl (1-naphthyl methylcarbamate) is an active insecticide in the carbamate family used in agricultural fields.[1]
Under the perturbation effect of cabaryl, the oscillating characteristic of the BZ reaction was evaluated and the oscillation period was used as a key parameter to assess the carbaryl content in real water samples
The concentrations were fixed and used throughout the experiments since the oscillation dynamics of this oscillatory system was dependent on the reactant concentrations

Summary

Introduction

Carbaryl (1-naphthyl methylcarbamate) is an active insecticide in the carbamate family used in agricultural fields.[1]. An indirect detection method of carbaryl based on hydrolysis in alkaline medium to form 1-naphthol was successfully determined by the copper(II)-catalyzed oscillating reaction implemented in a continuous-flow stirred tank reactor (CSTR).[24] The electrochemical setup is quite complicated with the reagent inflow and product outflow system. To the best of our knowledge, a spectrophotometric method for the direct detection of carbaryl insecticide in water samples based on an exploitation of the oscillating signals as the analytical tool has not been reported. Under the perturbation effect of cabaryl, the oscillating characteristic of the BZ reaction was evaluated and the oscillation period was used as a key parameter to assess the carbaryl content in real water samples. The standard deviation (SD) and relative standard deviation (RSD, in percentage) of the oscillation period under addition of different concentrations of carbaryl were calculated and evaluated. The chromatograms were recorded at 280 nm corresponding to the maximum absorption wavelength of carbaryl

Results and Discussion

Result

Conclusions