Vortex-assisted ionic liquid-based dispersive liquid–liquid microextraction for assessment of chromium species in artificial saliva extract of different chewing tobacco products

A novel dispersive liquid–liquid microextraction (ILDLLμE) method using an extracting solvent (ionic liquid) and dispersant (Triton X-114) was developed for the separation and preconcentration of hexavalent chromium (Cr⁶⁺) in artificial saliva extract (ASE) of chewing tobacco products, gutkha, and mainpuri (n = 23). In the proposed method, the extraction of Cr⁶⁺ was accomplished by using ammonium pyrrolidinedithiocarbamate (APDC) as complexing agent and 1-butyl-3-methylimidazolium hexafluorophosphate [C₄MIM] [PF₆] as extracting solvent. The tiny droplet of metal chelate was then dispersed into TX-114 emulsion, using vortex mixer. Various parameters such as concentration of APDC, pH of the solution, volume of [C₄MIM] [PF₆], and TX-114 as well as extraction time were studied. Under the most favorable conditions, the limit of detection was found to be 0.068 μg/L with the relative standard deviation <5 %. The enrichment factor of developed method was found as 62.5, and method has been effectively applied for the analysis of Cr species in artificial saliva extract of gutkha and mainpuri products. The Cr⁶⁺ was quantitatively recovered (<97 %) under optimal conditions, while the recovery of trivalent specie (Cr³⁺), at the same experimental conditions, was observed to be <5 %. The Cr³⁺ was determined by the difference of total Cr and Cr⁶⁺ in artificial saliva extract of selected STP. Health risks associated with the intake of total Cr in gutkha and mainpuri were assessed in terms of estimated daily intake, such as carcinogenic and noncarcinogenic risks. Estimated daily intake of Cr via chewing 10 g/day of gutkha and mainpuri was found to be below the maximum tolerable daily intake, whereas the calculated risk of cancer for Cr was observed in the acceptable range of 10E⁻⁶–10E⁻⁴, except some brands of gutkha. Graphical Abstract ᅟ