Preconcentration and Determination of Manganese in Water Samples Using N,N ′-bis(2-Hydroxy-5- bromo-benzyl)1,2 Diaminopropane

Abstract

The synthesis and analytical applications of N,N ′-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane (HBDAP) are described. The investigation includes a study of the characteristics that are essential for solvent extraction and for spectrophotometric determination and preconcentration of manganese. The organic phase loaded with Mn(II) from aqueous phase was stripped in one stage by using different mineral acid solutions. It was found that stripping efficiency was quantitative in case of HNO₃. A highly sensitive, selective and rapid spectrophotometric method is described for the determination of trace amounts of manganese(II) by HBDAP. This compound reacts with manganese(II) in the range of pH 7–10 to produce a brownish complex (2:3 mol ratio of Mn(II)/HBDAP) soluble in chloroform. The complex obeys Beer's law from 0.12 to 13.2 mg L⁻¹ with an optimum range. The relative standard deviations were % 0.02 (10 samples, each containing 3.2 mg L⁻¹ Mn(II)). The precision was determined from 30 results obtained for 2.75 mg L⁻¹ Mn(II); the mean value of a Mn(II) was 2.77 mg L⁻¹ with a standard deviation of 0.018 mg L⁻¹ Mn(II).

Keywords:

• Manganese(II) determination
• Spectrophotometry
• Solvent extraction
• Preconcentration, N,N ′-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane

Acknowledgments

This work was supported by The Scientific and Technical Research Council of Turkey (TÜBıTAK) (Project No: Misag-127. One of the authors (Derya KARA) thanks to the National Doctorate Scholarship (TÜBıTAK) for the fellowship.