Fabrication of montmorillonite composite alginate beads for micro-solid phase extraction of carbamate residues prior to their determination by ultra performance liquid chromatography-photodiode array detector.

Abstract

This paper reports the employment of natural montmorillonite (Cloisite Na⁺) and sodium alginate (Alg) to fabricate sorbent beads and applied for extraction and preconcentration of carbamates (CBMs) based on micro-solid phase extraction (μ-SPE) method prior to analysis by ultraperformance liquid chromatography coupled with a photodiode array detector (UPLC-PDA). Cloisite Na⁺/Alg composite bead was synthesized by ionic gelation method using calcium chloride as a cross-linking agent at ambient temperature. The biocomposite sorbent bead was then characterized by various techniques, including scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The parameters affected the extraction efficiency were investigated and optimized. Based on the optimal extraction conditions, the method provided linearity in the range of 1.0-1000 μg L^-1, with determination coefficient greater than 0.99. The limits of detection ranged between 0.7 and 10 μ g L^-1 for all analytes. The relative standard deviation was less than 4.6 % and 6.2 % for intra-day and inter-days, respectively. Finally, the μ-SPE-UPLC-PDA method was successfully used to CBMs residue detection in food and environment samples. The percentage recoveries were found in the range of 70-117 %. Moreover, the result in real sample found that no residue of the studied carbamates was observed in sample studies. The application of greenness and blueness assessment tools (AES, AGREE, and BAGI) confirmed that μ-SPE can be considered a green chemistry method. The proposed investigated method offers advantages such as low cost, simplicity, reduced solvent consumption, and minimal environmental impact, making it a promising alternative to conventional methods for carbamate pesticides analysis.