Preconcentration of Trace Neonicotinoid Insecticide Residues Using Vortex-Assisted Dispersive Micro Solid-Phase Extraction with Montmorillonite as an Efficient Sorbent.

Khwankaew Moyakao,Supalax Srijaranai,Jitlada Vichapong,Yanawath Santaladchaiyakit

doi:10.3390/molecules23040883

Abstract

In this work, we investigated montmorillonite for adsorption of neonicotinoid insecticides in vortex-assisted dispersive micro-solid phase extraction (VA-d-μ-SPE). High-performance liquid chromatography with photodiode array detection was used for quantification and determination of neonicotinoid insecticide residues, including thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid. In this method, the solid sorbent was dispersed into the aqueous sample solution and vortex agitation was performed to accelerate the extraction process. Finally, the solution was filtered from the solid sorbent with a membrane filter. The parameters affecting the extraction efficiency of the proposed method were optimized, such as amount of sorbent, sample volume, salt addition, type and volume of extraction solvent, and vortex time. The adsorbing results show that montmorillonite could be reused at least 4 times and be used as an effective adsorbent for rapid extraction/preconcentration of neonicotinoid insecticide residues. Under optimum conditions, linear dynamic ranges were achieved between 0.5 and 1000 ng mL−1 with a correlation of determination (R2) greater than 0.99. Limit of detection (LOD) ranged from 0.005 to 0.065 ng mL−1, while limit of quantification (LOQ) ranged from 0.008 to 0.263 ng mL−1. The enrichment factor (EF) ranged from 8 to 176-fold. The results demonstrated that the proposed method not only provided a more simple and sensitive method, but also can be used as a powerful alternative method for the simultaneous determination of insecticide residues in natural surface water and fruit juice samples.

Highlights

Neonicotinoids are a relatively new generation of pesticides that have been introduced to the market since the launch of pyrethroids [1]
The aim of this work is to develop a simple d-μ-solid-phase extraction (SPE) for preconcentration of neonicotinoid insecticides in surface water and fruit juice samples combined with High performance liquid chromatography (HPLC) for determination of target analytes
Method was proposed for preconcentration of neonicotinoid insecticides prior to analysis by HPLC

Summary

Introduction

Neonicotinoids are a relatively new generation of pesticides that have been introduced to the market since the launch of pyrethroids [1] This group of insecticides includes nitro-substituted (dinotefuran, nitenpyram, thiamethoxam, imidacloprid, and clothianidin) and cyano-substituted (acetamiprid and thiacloprid) compounds [2]. The widespread use of neonicotinoid insecticides at various stages of agricultural cultivation and during postharvest storage could give rise to serious risks for the health and safety of the consumers [4]. Restrictions in their agriculture use and maximum residue limits (MRLs) in some food commodities have been established [5]. The MRLs for neonicotinoids in fruit, vegetables, and cereals range from

Objectives

Findings

Discussion

Conclusion