Flame atomic absorption spectrometric determination of trace amounts of manganese in alloys and biological samples after preconcentration with the ion pair of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and ammonium tetraphenylborate on microcrystalline naphthalene or by column method.
Manganese is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)-ammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the pH range 7.5-10.5 from large volumes of aqueous solutions of various samples. After filtration, each solid mass consisting of the manganese complex and naphthalene was dissolved with 5 ml of dimethylformamide and the metal was determined by flame atomic absorption spectrometry. Manganese complex can alternatively be quantitatively adsorbed on ammonium tetraphenylborate-naphthalene adsorbent packed in a column and determined similarly. About 0.1 microgram of manganese can be concentrated in a column from 500 ml of aqueous sample, where its concentration is as low as 0.2 ppb. Eight replicate determinations of 1.0 ppm of manganese gave a mean absorbance of 0.224 with a relative standard deviation of 1.8%. The sensitivity for 1% absorption was 19 ppb. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of manganese in various standard samples.
Taher
M A
MA
Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran. taher@arg3.uk.ac.ir
D000497:Alloys / Q000032:analysis*; D001391:Azo Compounds / Q000737:chemistry*; D002138:Calibration; D002614:Chelating Agents / Q000737:chemistry*; D002708:Chlorella / Q000737:chemistry; D002852:Chromatography, Ion Exchange; D003460:Crystallization; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008345:Manganese / Q000032:analysis*; D009281:Naphthalenes; D010944:Plants / Q000737:chemistry; D012997:Solvents; D013054:Spectrophotometry, Atomic; D013775:Tetraphenylborate / Q000737:chemistry*
D000497:Alloys; D001391:Azo Compounds; D002614:Chelating Agents; D007202:Indicators and Reagents; D009281:Naphthalenes; D012997:Solvents; C037882:2-(5-bromo-2-pyridylazo)-5-diethylaminophenol; D008345:Manganese; D013775:Tetraphenylborate