TY - JOUR

T1 - Deep eutectic solvent as stationary phase for flow analysis: Automated trace metal determination in food products

AU - Шишов, Андрей Юрьевич

AU - Маркова, Ульяна Олеговна

AU - Муллоярова, Валерия Вячеславовна

AU - Толстой, Петр Михайлович

AU - Shkaeva, Natalya

AU - Kosyakov, Dmitry

AU - Das, Nipu Kumar

AU - Banerjee, Tamal

PY - 2024/12/1

Y1 - 2024/12/1

N2 - Background Deep eutectic solvents (DES) have emerged as effective solvents that address many challenges in analytical chemistry, particularly in microextraction. However, until now, their use has been primarily focused on extraction processes. This has significantly limited their application in analytical chemistry, especially in flow analysis, where the high viscosity of DES has made their use difficult. Results This paper presents a novel DES-based liquid-liquid microextraction approach for the separation and determination of trace metals in foods using an automated flow analysis system. In this study, a DES composed of thymol and thionalide was first prepared and thoroughly characterized by spectroscopic (IR, NMR) and differential scanning calorimetry techniques. The COSMO-SAC model was employed to predict the solubility of metal salts (Cu, Cd, Pb, and Hg) in the new DES. The solvent was applied to glass fiber as a stationary phase in an extraction column in a flow analysis. After microwave digestion of food samples, metals were extracted by this DES in an automated mode and subsequently eluted with an aqueous thiourea solution. The procedure demonstrated limits of detection (LOD) of 6 μg kg−1 for mercury, 4 μg kg−1 for copper, 6 μg kg−1 for lead and 0.6 μg kg−1 for cadmium. Significance This study represents the first application of a DES-based stationary phase in automated flow analysis, significantly enhancing extraction efficiency. The procedure enables precise and reliable determination of trace metals in food products, aligning with green chemistry principles by minimizing waste.

AB - Background Deep eutectic solvents (DES) have emerged as effective solvents that address many challenges in analytical chemistry, particularly in microextraction. However, until now, their use has been primarily focused on extraction processes. This has significantly limited their application in analytical chemistry, especially in flow analysis, where the high viscosity of DES has made their use difficult. Results This paper presents a novel DES-based liquid-liquid microextraction approach for the separation and determination of trace metals in foods using an automated flow analysis system. In this study, a DES composed of thymol and thionalide was first prepared and thoroughly characterized by spectroscopic (IR, NMR) and differential scanning calorimetry techniques. The COSMO-SAC model was employed to predict the solubility of metal salts (Cu, Cd, Pb, and Hg) in the new DES. The solvent was applied to glass fiber as a stationary phase in an extraction column in a flow analysis. After microwave digestion of food samples, metals were extracted by this DES in an automated mode and subsequently eluted with an aqueous thiourea solution. The procedure demonstrated limits of detection (LOD) of 6 μg kg−1 for mercury, 4 μg kg−1 for copper, 6 μg kg−1 for lead and 0.6 μg kg−1 for cadmium. Significance This study represents the first application of a DES-based stationary phase in automated flow analysis, significantly enhancing extraction efficiency. The procedure enables precise and reliable determination of trace metals in food products, aligning with green chemistry principles by minimizing waste.

KW - Deep eutectic solvent

KW - Stationary phase

KW - Trace metal extraction

KW - Flow analysis

KW - ICP-OES

KW - Food samples

U2 - 10.1016/j.aca.2024.343356

DO - 10.1016/j.aca.2024.343356

M3 - Article

VL - 1332

JO - Analytica Chimica Acta

JF - Analytica Chimica Acta

SN - 0003-2670

M1 - 343356

ER -