A b s t r a c t
A simple, fast, and sensitive method for speciation and determination of As (III, V) and Hg (II, R) in human blood samples based on ionic liquid-dispersive liquid–liquid microextraction (IL-DLLME) and flow injection hydride generation/cold vapor atomic absorption spectrometry (FI-HG/CV-AAS) has been developed. Tetraethylthiuram disulfide, mixed ionic liquids (hydrophobic and hydrophilic ILs) and acetone were used in the DLLME step as the chelating agent, extraction and dispersive solvents, respectively. Using a microwave assisted-UV system, organic mercury (R—Hg) was converted to Hg(II) and total mercury amount was measured in blood samples by the presented method. Total arsenic content was determined by reducing As(V) to As(III) with potassium iodide and ascorbic acid in a hydrochloric acid solution. Finally, As(V) and R—Hg were determined by mathematically subtracting the As(III) and Hg(II) content from the total arsenic and mercury, respectively. Under optimum conditions, linear range and detection limit (3σ) of 0.1–5.0 μg L−1 and 0.02 μg L−1 for As(III) and 0.15–8.50 μg L−1 and 0.03 μg L−1 for Hg(II) were achieved, respectively, at low RSD values of < 4 % (n = 10). The developed method was successfully applied to determine the ultratrace amounts of arsenic and mercury species in blood samples; the validation of the method was performed using standard reference materials. c 2015 Institute of Chemistry, Slovak Academy of Sciences
Hamid Shirkhanloo, Aisan Khaligh, Hassan Zavvar Mousavi*, Mohammad Mehdi Eskandari, Ali Akbar Miran-Beigi
Results and discussion
To reach high enrichment factor and good sensitivity and precision of mercury and arsenic speciation and determination in blood samples, the proposed IL DLLME method was optimized for various analytical parameters such as solution pH, concentration of the chelating agent, amounts of ILs, sample volume, etc.