Efficiency of different green shaking extraction methods for the preconcentration of trace quantity of mercury in artificial saliva extract of snuff products: impact on adult consumers

The present study is based on developing a dual-step ultrasonically modified cloud point extraction (DsUm-CPE) method for enrichment of mercury (Hg) in artificial saliva extract (ASE) of the numerous snuff products (dry and moist snuff, having green, brown and black in colors). This method relies on the complexation of Hg with ammonium O, O-diethyldithiophosphate, followed by the entrapped in nonionic surfactant (Triton X-114) prior to analysis by cold vapor atomic absorption spectrometry (CVAAS). The dispersion of hydrophobic complex in micellar phase was carried out by ultrasound energy, in addition other shaking method, vortex mixer was also applied for comparison purposes, vortex shaking method was also used. Several variables of developed methods, such as complexing agent, Triton X-114, dispersion modes (sonication/vortex shaking), equilibrium temperature, centrifugation time and concentration of back extraction reagent, have been studied. The detection and quantification limit under the optimum conditions were attained as 0.004 and 0.014 mu g L-1, respectively. The accuracy for the analysis of total Hg was checked by certified samples of Virginia tobacco leaves (ICHTJ-cta-VTL-2) and both biological samples. The obtained values of all three certified samples have insignificant difference (p > 0.05) among their certified and experimental values. The resulted statistics specified that dry snuff has about fourfold higher contents of Hg as compared to moist snuff, whereas the biological samples of male subject (25 to 60 years) sniffing moist and dry snuff were also analyzed to assess the Hg exposure through their consumption. The biological samples of snuff consumers have about twofold higher concentration of Hg as compared to referents.

Automated summary

A dual-step ultrasonically modified cloud point extraction method was developed for enrichment of mercury in various tobacco products, with dry snuff containing about four times higher Hg content than moist snuff. The method involved complexing Hg with diethyldithiophosphate, entrapping in surfactant, and analysis by atomic absorption spectrometry. Analysis of biological samples showed twice the Hg concentration in snuff consumers compared to referents.