DETERMINATION OF LEAD IN BLOOD BY SQUARE-WAVE ANODIC-STRIPPING VOLTAMMETRY AT A CARBON DISK ULTRAMICROELECTRODE

A method for blood lead ([Pb]) analysis is developed based on square w ave anodic stripping voltammetry (SWASV) in an Hg2+-containing solutio n using a 10-mu m-diameter carbon disk ultramicroelectrode. SWASV elim inates interference from O-2 in unsparged blood-derived sample solutio ns, and filtration of acidified samples through nitrocellulose reduces the concentration of interfering substances, increasing the size and improving the uniformity of peak currents. Blood [Pb] values obtained by SWASV are compared with blood [Pb] values determined by graphite fu rnace atomic absorption spectrophotometry; good accuracy and reasonabl e coefficients of variation in the range 10.6-20% (average of 13.5%) a re found for blood [Pb] ranging from 4 to 30 mu g/dL. Preliminary expe riments using a carbon disk microarray electrode suggest future improv ements in sensitivity.