title: Determination of trace levels of manganese in various biological and environmental samples by atomic absorption spectrometry after solid-liquid extraction and preconcentration with the ion pair formed by the nitroso-S anion and the tetradecyldimethylbenzylammonium cation.
abstract: Manganese is quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S) and tetradecyldimethylbenzylammonium (TDBA) chloride on microcrystalline naphthalene in the pH range 9.5-10.6 from large volumes of aqueous solutions of various samples. After filtration, the solid mass consisting of the manganese complex and naphthalene is dissolved in 5 mL dimethylformamide and the metal is determined by flame atomic absorption spectrometry. Alternatively, the manganese complex can be quantitatively adsorbed on TDBA-naphthalene adsorbent packed in a column and determined similarly. About 0.2 microg manganese can be concentrated in a column from 400 mL aqueous sample with a concentration as low as 0.5 ng/mL. Eight replicate determinations of manganese at 0.8 microg/mL gave a mean absorbance of 0.156 for the final solution with a relative standard deviation of 1.4%. The sensitivity for 1% absorption was 23 ng/mL. The interference of a large number of anions and cations was studied, and the optimized conditions developed were used for trace determinations of manganese in various alloys, and in biological and environmental samples.
authors: Payame Noor University of Kerman, Iran.
authors: M A
authors: MA
authors: Taher
authors: A M
authors: AM
authors: Dehzoei
mesh_terms: D000327:Adsorption; D000497:Alloys / Q000032:analysis; D001548:Benzalkonium Compounds; D003460:Crystallization; D006197:Hair / Q000737:chemistry; D006801:Humans; D007202:Indicators and Reagents; D008345:Manganese / Q000032:analysis*; D009281:Naphthalenes; D009282:Naphthalenesulfonates; D012680:Sensitivity and Specificity; D012997:Solvents; D013054:Spectrophotometry, Atomic; D013232:Steel / Q000032:analysis; D013662:Tea / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000497:Alloys; D001548:Benzalkonium Compounds; D007202:Indicators and Reagents; D009281:Naphthalenes; D009282:Naphthalenesulfonates; D012997:Solvents; D013662:Tea; D014867:Water; D013232:Steel; C005883:zephiramine; C031721:naphthalene; D008345:Manganese; C034787:2-nitroso-1-naphthol-4-sulfonic acid