title: Optimization of a new methodology for trace determination of elements in biological fluids: Application for speciation of inorganic selenium in children's blood.
abstract: The continuous sample drop flow microextraction (CSDFME) joined with the iridium-modified tube graphite furnace atomic absorption spectrometry (GFAAS) has been developed as a highly sensitive technique for the speciation of selenium in blood samples. In this method 32.0μl carbon tetrachloride is transferred to the bottom of a conical sample cup. Then the 5.0ml of aqueous solution transforms to fine droplets while passing through the organic solvent. At this stage, Se(IV)-APDC hydrophobic complex is extracted into the organic solvent. After extraction, the conical sample cup is transferred to the GFAAS and 20μl of extraction solvent was injected into the graphite tube by the aim of autosampler. Under the optimum conditions, the calibration graph was linear in the range of 0.06-3.0μgl-1with detection limit of 0.02μgl-1. The enrichment factor and enhancement factor were 106 and 91, respectively. Repeatability (intra-day) and reproducibility (inter-day) of method based on seven replicate measurements of 2.5μgl-1of selenium were 3.7% and 4.2%, respectively. Total inorganic Se(IV, VΙ) was measured after reduction of Se(VΙ) with gentle boiling in 5M HCl medium for 50min and adjusting pH to 3, and the concentration of Se(VΙ) was calculated by subtracting the Se(IV) concentration from the total selenium concentration.
authors.affiliation: School of Medical, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Akramipour
authors.affiliation: School of Medical, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Hemati
authors.affiliation: Research Center for Environmental Determinants of Health (RCEDH), Kermanshah University of Medical Sciences, Kermanshah, Iran. Electronic address: nazirfatahi@yahoo.com.
authors.forename: Nazir
authors.initials: N
authors.lastname: Fattahi
authors.affiliation: Research Center for Environmental Determinants of Health (RCEDH), Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Meghdad
authors.initials: M
authors.lastname: Pirsaheb
authors.affiliation: Clinical Research Development Center, Imam Khomeini Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Toraj
authors.initials: T
authors.lastname: Ahmadi-Jouibari
mesh_terms: D002648:Child; D006801:Humans; D015203:Reproducibility of Results; D012643:Selenium / Q000097:blood*; D012997:Solvents; D013054:Spectrophotometry, Atomic; D014874:Water Pollutants, Chemical
chemical_list: D012997:Solvents; D014874:Water Pollutants, Chemical; D012643:Selenium
keywords: Chemical analysis; Children’s blood; Continuous sample drop flow microextraction; Graphite furnace atomic absorption spectrometry; Selenium speciation