Sustainable liquid-liquid microextraction and determination of inorganic arsenic species in nut-based beverages using hydrophobic natural deep eutectic solvents

Abstract

Arsenic (As) is a carcinogenic, mutagenic, and toxic element, making its determination in food and beverages essential for assessing its impact on human health. Since the total As content alone does not provide adequate information on toxicity and bioavailability, it is crucial to develop methods for the speciation of As(III) and As(V). The aim of this work was to develop an efficient and selective method for the determination of inorganic As (iAs) species in complex samples such as nut-based beverages. This method involves the application of a hydrophobic natural deep eutectic solvent (HNADES) in the vortex-assisted liquid-liquid microextraction (VALLME) technique based on the solidification of floating droplets. The As(III) species was complexed with ammonium pyrrolidinedithiocarbamate (APDC) and extracted using 50 μL of HNADES capric acid:lauric acid(CAP:LAU) (2:1). Then, As(III) species was determined by hydride generation atomic fluorescence spectrometry (HG-AFS). Optimization of the sample volume, HNADES volume, vortex stirring time, and cooling time was performed using a multivariate study. The method contributes to the development of a more environmentally friendly analytical approach and offers several advantages, including 100 % As(III) extraction efficiency, low limits of detection (0.11 μg L⁻1 for As(III) and 0.30 μg L⁻1 for As(V)), and excellent selectivity.