Abstract
Simple and rapid preconcentration methods viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As3+ and total inorganic arsenic (iAs) in artificial saliva extract (ASE) of smokeless tobacco (SLT) product (mawa). The iAs species were separated from organic As by adsorbing on titanium dioxide (TiO2), whereas the organic As was eluted out. The retained iAs species was eluted by 1.0mL of 0.5M NaOH solution. The CPE method has been used for the preconcentration of As3+, using ammonium pyrrolidinedithiocarbamate (APDC) as complexing reagent. The resulting solutions of each method were determined by electrothermal atomic absorption spectrometry with a mixture of palladium and magnesium nitrates as modifier. The % recovery of As3+ and iAs were found to be >98%. The adsorption capacity of TiO2 for iAs was calculated to be 11.5mgg−1. The accuracy of methods was tested by simultaneously analyzing certified reference material, Virginia tobacco leaves and spike recovery test. Under the optimized experimental conditions, the detection limits for As3+ and iAs were 28 and 20ngmL−1 for CPE and SPE, respectively. The enrichment factor for SPE and CPE were obtained as 25 and 20, respectively. The concentration of As+3 and As5+ were found in the range of 26–45 and 50–98ngg−1, respectively in studied SLT product. The artificial saliva extractable arsenic (As) corresponds to 19%–25%, of total As in SLT product.
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•Artificial saliva extract of As from SLT products, emphasizes their immediate exposure.•The ability to quantify As speciation in SLT products makes this a useful biomonitoring approach.•Advanced extraction methods used for the speciation of As are simple and environmentally friendly.