title: Determination of nickel in blood and serum samples of oropharyngeal cancer patients consumed smokeless tobacco products by cloud point extraction coupled with flame atomic absorption spectrometry.
abstract: Oropharyngeal cancer is a significant public health issue in the world. The incidence of oropharyngeal cancer has been increased among people who have habit of chewing smokeless tobacco (SLT) in Pakistan. The aim of present study was to evaluate the concentration of nickel (Ni) in biological samples (whole blood, serum) of oral (n = 95) and pharyngeal (n = 84) male cancer patients. For comparison purposes, the biological samples of healthy age-matched referents (n = 150), who consumed and did not consumed SLT products, were also analyzed for Ni levels. As the Ni level is very low in biological samples, a preconcentration procedure has been developed, prior to analysis of analyte by flame atomic absorption spectrometry (FAAS). The Ni in acid-digested biological samples was complexed with ammonium pyrrolidinedithio carbamate (APDC), and a resulted complex was extracted in a surfactant Triton X-114. Acidic ethanol was added to the surfactant-rich phase prior to its analysis by FAAS. The chemical variables, such as pH, amounts of reagents (APDC, Triton X-114), temperature, incubation time, and sample volume were optimized. The resulted data indicated that concentration of Ni was higher in blood and serum samples of cancer patients as compared to that of referents who have or have not consumed different SLT products (p = 0.012-0.001). It was also observed that healthy referents who consumed SLT products have two to threefold higher levels of Ni in both biological samples as compared to those who were not chewing SLT products (p < 0.01).
authors.affiliation: National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080, Pakistan, ssadiashafi@gmail.com.
authors.forename: Sadaf Sadia
authors.initials: SS
authors.lastname: Arain
authors.forename: Tasneem Gul
authors.initials: TG
authors.lastname: Kazi
authors.forename: Jamshed Bashir
authors.initials: JB
authors.lastname: Arain
authors.forename: Hassan Imran
authors.initials: HI
authors.lastname: Afridi
authors.forename: Atif Gul
authors.initials: AG
authors.lastname: Kazi
authors.forename: Syeda
authors.initials: S
authors.lastname: Nasreen
authors.forename: Kapil Dev
authors.initials: KD
authors.lastname: Brahman
mesh_terms: D000328:Adult; D003710:Demography; D006801:Humans; D008297:Male; D008409:Mastication; D008875:Middle Aged; D009532:Nickel / Q000097:blood*; D016017:Odds Ratio; D009959:Oropharyngeal Neoplasms / Q000097:blood*; D010154:Pakistan; D012307:Risk Factors; D044967:Serum; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014030:Tobacco, Smokeless
chemical_list: D009532:Nickel