Screening of cadmium and lead in potentially contaminated waters using a spectrophotometric sequential injection lab-on-valve methodology

摘要

The presentworkdescribesthedevelopmentofa mSI-LOVmethodforthesimultaneousscreeningofcadmium andleadinpotentiallycontaminatedwatersamples.Toattainthebiparametricdetermination,dithizone waschosenasthespectrophotometricreagentasitformsacoloredcomplexwithbothmetalions, atdifferentpHconditions.Thecadmiumdeterminationwasattainedinstrongalkalineconditions(pHE12);theleaddeterminationwascalculatedbythedifferencewiththedeterminationofbothmetals inmildalkalineconditions(pHE8). Thecoloredcomplexwasmeasuredat550nmandthemethod presentedaLODof34 μg L 1 for cadmiumand56 μg L 1 for lead,withasampleconsumptionof 20 mL perassayandadeterminationrateof55h 1. Theresultsobtainedwereinagreementwiththoseobtained byFAAS.Thedevelopedmethodwasefficiently appliedtothescreeningofcadmiumandleadinmarine portwaters.