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Ultrasonic Extraction/Anodic Stripping Voltammetry for Determining Lead in Dust: A Laboratory Evaluation.


pdf icon Ultrasonic Extraction/Anodic Stripping Voltammetry for Determining Lead in Dust: A Laboratory Evaluation. (816 K)
Rossiter, W. J., Jr.; Toman, B.; McKnight, M. E.; Emenanjo, I.; Anaraki, M. B.

NISTIR 6998; 47 p. October 2004.

Keywords:

dust; lead; evaluation; anodic stripping voltammetry (ASV); building technology; dust wipes; lead containing dust; lead recovery; operator effect; tests; ultrasonic extraction (UE)

Abstract:

Previously published laboratory studies have indicated that ultrasonic extraction/anodic stripping voltammetry (UE/ASV) may be suitable for quantitative field analysis of dust wipe samples. Nevertheless, on-site lead extraction and analysis of dust wipes by UE/ASV are not currently used in federal programs for controlling and abating lead hazards in housing. A reservation to adopting UE/ASV is that the effect of the field operator (i.e., the analyst) is unknown. The availability of a reliable field test procedure for determining the amount of lead in dust could allow for on-site extraction and analysis. Thus, the U.S. Department of Housing and Urban Development (HUD) sponsored a study to evaluate the effect of operator when certified lead risk assessors or inspectors, trained to conduct UE/ASV analyses, performed such analyses of laboratory-prepared dust wipe specimens using commercial, field-portable apparatus. Four operators analyzed 640 dust wipe specimens following a test protocol developed in accordance with the UE/ASV apparatus instructions. These specimens were prepared using four commercial wipes spiked with one of six lead-containing certified reference materials (CRMs). Six lead levels spanned a range from 0 mg to 2000 mg. After UE extraction, the solutions were either filtered or not filtered before conducting the ASV analyses. Key findings from these analyses were that lead recoveries were quite variable, ranging from < 20% to > 100% depending upon the combination of experimental variables, and only 42% of the specimens spiked with a CRM afforded quantitative recovery defined as falling within the range of 100% - 20%. When the entire data set was analyzed, all experimental variables had a significant effect on recovery. The majority of the twoway interaction effects were also significant. The operator effect was essentially associated with three of the four operators determining higher lead recoveries than the fourth. The three operators reporting the higher recoveries followed a test protocol that was a slight modification of that used by the fourth operator. It was not determined whether this modification accounted for the observed operator effect.