title: Column preconcentration of trace manganese with the ion pair of 2-nitroso-1-naphthol-4-sulfonic acid tetradecyldimethylbenzyl-ammonium chloride supported on naphthalene and determination by derivative spectrophotometry.
abstract: A column preconcentration method has been developed for the determination of trace amounts of manganese by preconcentration on 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S)-tetradecyldimethylbenzylammonium (TDBA) naphthalene as an adsorbent using a simple funnel tipped glass tube. Manganese reacts with nitroso-S to form a water soluble brown colored chelate anion. The chelate anion forms a water insoluble Mn-Nitroso-S-TDBA ion pair on naphthalene packed in a column in the pH range 9.6-10.5 at a flow rate of 1-2 ml/min. The solid mass consisting of manganese complex and naphthalene is dissolved in 5 ml of dimethylformamide (DMF) and the metal determined by second derivative spectrophotometry. The calibration curve is linear in the concentration range 0.25-35.0 micrograms of Mn in 5 ml of the final DMF solution. Eight replicate determinations of 25 micrograms of standard manganese solution give a mean peak height of 4.0 with a correlation coefficient of 0.9995 and relative standard deviation of +/- 1.1%. The sensitivity was calculated to be 0.502(d2 A/d lambda 2)/microgram ml-1 from the slope of the calibration curve. The detection limit was 0.020 microgram ml-1 for manganese at the minimum instrumental settings (signal to noise ratio = 2). Various parameters effecting the method such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of manganese have been evaluated to optimize the conditions for its determination in standard alloys and biological samples.
authors.affiliation: Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran.
authors.forename: M A
authors.initials: MA
authors.lastname: Taher
authors.forename: B K
authors.initials: BK
authors.lastname: Puri
authors.forename: A K
authors.initials: AK
authors.lastname: Malik
mesh_terms: D000327:Adsorption; D000995:Antitubercular Agents / Q000737:chemistry*; D001389:Azirines; D001548:Benzalkonium Compounds / Q000737:chemistry*; D001565:Benzoates; D002138:Calibration; D004784:Environmental Monitoring; D007202:Indicators and Reagents / Q000737:chemistry*; D008345:Manganese / Q000032:analysis*; D009281:Naphthalenes / Q000737:chemistry; D009282:Naphthalenesulfonates / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D000995:Antitubercular Agents; D001389:Azirines; D001548:Benzalkonium Compounds; D001565:Benzoates; D007202:Indicators and Reagents; D009281:Naphthalenes; D009282:Naphthalenesulfonates; C005883:zephiramine; C031721:naphthalene; D008345:Manganese; C034787:2-nitroso-1-naphthol-4-sulfonic acid; C051320:4-(3-trifluoromethyldiazirino)benzoic acid