Deep Eutectic Solvent Stir Bar Sorptive Extraction: A Rapid Microextraction Technique for the Determination of Vitamin D3 by Spectrophotometry

In this paper, anew microextraction method, named deep eutecticsolvent stir bar sorptive extraction (DES-SBSE), is describedthat utilizes a hydrophobic DES (hDES) as a coating for SBSE. As amodel, vitamin D-3 was extracted efficiently by this techniquefrom different real samples before its spectrophotometric determination.A conventional magnet was encapsulated inside a glass bar (1.0 cmx 2 mm) and coated by the hDES consisting of tetrabutylammoniumchloride and heptadecanoic acid (mole ratio 1:2). Parameters affectingmicroextraction were studied and optimized by one-variable-at-a-time,central composite design, and Box-Behnken design methods. Underthe optimum conditions, the detection limit of 0.08 & mu;g L-1 could be reached. The linear range of the methodwas between 0.5 and 1000.0 & mu;g L-1 for theanalyte. Precision for intraday repeatability and interday reproducibilityof the method was better than 3.1 and 4.2, respectively. A singlestir bar could be used for at least 50 successive extractions andthe batch-to-batch reproducibility of SB coated with hDES was 4.5%.

Automated summary

This paper introduces a new microextraction method called deep eutectic solvent stir bar sorptive extraction (DES-SBSE) that uses a hydrophobic DES (hDES) as a coating for SBSE. Vitamin D-3 was efficiently extracted from different real samples using this technique and spectrophotometrically determined. The parameters affecting microextraction were studied and optimized using various methods. Under the optimal conditions, the method achieved a detection limit of 0.08 μg/L. The linear range of the method was 0.5 to 1000.0 μg/L for the analyte. The method showed good precision for intraday repeatability and interday reproducibility, with values better than 3.1 and 4.2, respectively. A single stir bar could be used for at least 50 successive extractions, and the batch-to-batch reproducibility of SB coated with hDES was 4.5%.