Development of Hyphenated Techniques with ETAAS for Determination of Ultra-Traces of Manganese and Vanadium and Their Speciation in Environmental Samples

The technique of in-situ electrodeposition, coupled with etaas (ed-etaas), has beendeveloped for determination of ultra-traces of manganese and vanadium in environmentalsamples. the goal is electrodeposition of ultra-traces of analyte onto the renewable pd-coatedsubstrate at optimized conditions of voltage, time of deposition and ph of sample solution priorto measurement by etaas. the characteristic masses in the determination of manganese andvanadium are superior to those of conventional etaas (conv-etaas) measurements. thedetection limits for the interested elements have been improved over those of conv-etaas,with precision of the determinations in the range of 1-3 rsd%. in this work, a technique wasdeveloped for speciation of these elements in the environmental samples. therefore, a solidphase extraction method, coupled with etaas or ed-etaas, has been investigated for thispurpose. the results showed that it could be a fast and sensitive method for manganese andvanadium speciation. a c18 cartridge, modified with sodium diethyldithiocarbamate (sddtc),has been employed for the selective separation of manganese (vii) ions from other associatedmetal ions, especially manganese (ii), even at much higher concentrations, followed by edetaasdetermination. to separate vanadium (iv) from vanadium (v), a modified membranedisk loaded with disodium ethylenediaminetetraacetic acid (na2edta) was used to trap bothvanadium species, then, the vanadium (iv) ion was eluted selectively and ed-etaas was usedfor determination.