Speciation of Manganese in blood serum- analytical methods developmentand optimization for the extraction, pre-concentration and determination

Abstract

The analytical methods for speciation of manganese in three different types of matrices (water, milk and blood serum) was studied. Supported liquid membrane (SLM) extraction was optimized and successfully used for the extraction and preconcentration on Mn(II) from water, milk and blood serum. The extractant used was 15% (v/v) DEHPA with an organic membrane modifier, 10% (v/v) TOPO. All determinations of Mn(II) were carried out using Adsorptive Stripping Voltammetry. A SLM membrane probe was developed and used for the extraction of Mn(II) from smaller water, milk and blood serum samples. Membrane probe depth was optimized: probe depth - 2mm below donor solution. The membrane probe yielded higher extraction efficiencies compared to the flat spiral disk SLM unit.

The Adsorptive Stripping Voltammetry method used for the determination of Mn(II) in water was optimized and used in other applications (determination of Mn(II) in aged and fractionated blood serum). The optimum conditions obtained: pH = 7.5-8.0, deposition potential = -(1.9V-2.0V), deposition time = 45-65s, equilibration time = 5s, stirring speed = 2000rpm, and no gelatin addition. The AdSV optimized parameters were then used for the analysis of Mn(II) in aged whole and fractionated blood serum. Size exclusion chromatography was used to obtain the blood serum fractions. It was determined that with aging, the concentration and thus extraction efficiency of free Mn(II) in blood serum matrix decreases. The spiked blood serum fractions were extracted and Mn(II) was determined with adequate reproducibility.