A b s t r a c t

On-line solid phase extraction (SPE) based on nano adsorbent for pre-concentration of inorganic arsenic in water and waste water samples was developed prior to determine by hydride generation atomic absorption spectrometry (HGAAS). By hydride generation simulation system (HGSS), the inorganic arsenic in liquid samples changed to hydride form and pass through nano platinum multi wall carbon nanotube (3 wt % Pt, NPt-MWCNT,). The hydride form of arsenic (AsH₃), pre-concentrated on NPt-MWCNTs and then completely desorption by electric heater accessory at 200oC for determining. The detection limit (LOD) and linear range of perposed method were obtained 0.4 ng L^-1 and 6 –410 ng L^-1 respectively(R² = 0.9988). The relative standard deviations (%RSD) at 100 ng L-1 of analyte were found less than 5%. The capacity and efficiency of nano adsorbent were 75 mg g^-1 and 96% at argon flow rate less than 100 ml min^-1. The developed method was applied successfully to determination of ultra trace of inorganic arsenic in environmental samples by HG-AAS.

Hamid Shirkhanloo, Ali Akbar Miran Beigi, Amir Vahid, Nasrin Shirkhanloo, Behzad Kalantri and Hossein Ali Ghadirian

A b s t r a c t

Anew speciation and preconcentration method based on dispersive liquid-liquid microextraction has been developed for trace amounts of As(III) and As(V) in urine and water samples. At pH 4, As(III) is complexed with ammoniumpyrrolidine dithiocarbamate and extracted into 1-Hexyl-3-methylimidazolium hexafluorophosphate, as an ionic liquid (IL) and As(III) is determined by electrothermal atomic absorption spectrometery (ETAAS). Arsenic(V) in the mixing solution containing As(III) and As(V) was reduced by using KI and ascorbic acid in HCl solution and then the procedure was applied to determination of total arsenic. Arsenic(V) was calculated as the difference between the total arsenic content and As(III) content. The effect of various parameters on the recovery of the arsenic ions has been studied. Under the optimum conditions, the enrichment factor 135 was obtained. The proposed method was successfully applied to the determination of trace amounts of As(III) and As(V) in water and biological samples.

Hamid Shirkhanloo, Hassan Zavvar Mousavi and Ahmad Rouhollah

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

A b s t r a c t

A noble method for pre-concentration and speciation of ultra trace As (III) and As (V) in urine and whole blood samples based on dispersive liquid-liquid microextraction (DLLME) has been developed. In this method, As (III) was complexed with ammonium pyrrolidine dithiocarbamate at pH = 4 and Then, As (III) was extracted into the ionic liquid (IL). Finally, As (III) was back-extracted from the IL with hydrochloric acid (HCl) and its concentration was determined by flow injection coupled with hydride generation atomic absorption spectrometry (FI-HGAAS). Total amount of arsenic was determined by reducing As (V) to As (III) with potassium iodide (KI) and ascorbic acid in HCl solution and then, As (V) was calculated by the subtracting the total arsenic and As (III) content. Under the optimum conditions, for 5-15 mL of blood and urine samples, the detection limit (3σ) and linear range were achieved 5 ng L−1 and 0.02-10 μg L−1, respectively. The method was applied successfully to the speciation and determination of As (III) and As (V) in biological samples of multiple sclerosis patients with suitable precision results (RSD < 5%). Validation of the methodology was performed by the standard reference material (CRM).

Hamid Shirkhanloo,†,‡ Ahmad Rouhollahi,†,* and Hassan Zavvar Mousavi§