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An efficient and simple deep eutectic solvent (DES)-based liquid phase microextraction method has been used for chromotrope 2R dyestuff at trace levels prior to its UV-Vis spectropthometric determination. In this aspect, DES was prepared by decanoic acid and tetra-n-butylammonium bromide component used as 1:3 molar ratios. The developed separation-preconcentration method was optimised various analytical parameters such as pH, sample volume, eluent sample volume, volume of DES, sample volume of tetrahydrofuran (THF) and matrix effect etc. on the recovery of chromotrope 2R dyestuff were investigated. Quantitative recovery data for chromotrope 2R were found at pH 3.0. The detection limits of the chromotrope 2R were found to be as 5.4 µg L−1. The accuracy of the developed method was successfully applied by the determination of the addition-recovery studies in the water sample, detergent and food samples with satisfactory results. The proposed method was applied to natural water samples for the determination of chromotrope 2R with satisfactory results. [ABSTRACT FROM AUTHOR]

A simple and fast microextraction procedure based on supramolecular solvent extraction of malachite green from water samples has been established in the presented work. The effective analytical parameters including pH, solvent volume, sample volume etc. on the quantitative recoveries of the malachite green were optimised. Matrix effects were also investigated. The preconcentration factor was found as 50. The limit of detection and limit of quantification were 16.3 and 54.5 µg L−1, respectively. The relative standard deviation percentage was below 7%. The presented procedure was applied to the determination of malachite green content of natural water samples from fish farm and tap water etc. [ABSTRACT FROM AUTHOR]

In the presented study, the usability of hydrolytic enzyme immobilized magnetic nanoparticles as an extraction agent for the microextraction of metal ions from food samples was investigated. α-amylase modified magnetic carbon nanotubes (α-amylase-Fe 3 O 4 /MWCNTs) was used as an extraction agent for direct microextraction of trace arsenic from food sample phase into liquid phase medium prior to its ICP-MS determination. In extraction studies using hydrolytic enzymes, it is impossible to recover the free soluble enzyme after extraction without losing its activity. In our study, this problem was overcome by immobilizing the hydrolytic enzyme on magnetic support. In this way, α-amylase-Fe 3 O 4 /MWCNTs as an extraction agent with a reuse property of at least six times was used. α-amylase-Fe 3 O 4 /MWCNTs was characterized by FT-IR, XRD, SEM, SEM-EDX, VSM, TGA, and DTG techniques. Optimization of the presented method was performed using 1568 A rice flour certified reference material. Analytical parameters such as type of hydrolytic enzyme, pH and volume of the aqueous phase, extraction temperature and ultrasonic irridation time were optimized. The microextraction step was performed in ultrasonic water bath within only ∼15 min. Limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD %) values for the developed method were found to be 14.3 μg kg−1, 47.3 μg kg−1 and 7.5%, respectively. The method was successfully applied to the analysis of arsenic contents of different rice and flour samples. [Display omitted] • The usability of hydrolytic enzyme immobilized magnetic nanoparticles as an extraction agent for the microextraction of metal ions from food samples was investigated. • α-amylase immobilized magnetic carbon nanotubes succeeded direct microextraction of trace arsenic from food sample phase into liquid phase medium. • α-amylase immobilized magnetic carbon nanotubes has a reuse property of at least six times without losing its activity. [ABSTRACT FROM AUTHOR]