Developing a new and simple natural deep eutectic solvent based ultrasonic-assisted microextraction procedure for determination and preconcentration of As and Se from rice samples
A novel, green, and rapid natural deep eutectic solvent (NADES)-based ultrasonic-assisted microextraction procedure (UAME) was developed for extraction of arsenic (As) and selenium (Se) from rice samples prior to their determination by hydride generation atomic absorption spectrometry (HG-AAS). Microwave digestion was used in rice sample preparation. The preparation of NADESs was simple and inexpensive. The recommended method was based on the extraction of the ion pair complexes of As(iii) and Se(iv) by celestin blue at pH 6.5 to the NADES phase by the ultrasonic effect. The parameters (NADES type and volume, ultrasonic conditions, pH, amount of complexing agent, interference effect) affecting the extraction were studied and optimized in detail. Under optimized conditions, the linear range, detection limit, and sensitivity improvement factor for Se(iv) was 10-450 ng L-1, 3.0 ng L-1 and 84, respectively, while the same analytical parameters for As(iii) were 5-330 ng L-1, 1.7 ng L-1 and 97, respectively. The validity of the recommended method was evaluated with the analysis of standard reference materials (SRMs) and recovery experiments. After reduction using a mixture of ascorbic acid and potassium iodide, the recommended method was applied for determination of total inorganic As and Se in rice samples. © 2019 The Royal Society of Chemistry.