Ultrasonic Extraction/Anodic Stripping Voltammetry for Determining Lead in Dust: A Laboratory Evaluation
Walter J. Rossiter Jr, Blaza Toman, M E. McKnight, I Emenanjo, M Baghai Anaraki
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 performed UE/ASV analyses of 640 dust wipe specimens following a test protocol that was developed in accordance with the supplier s 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 ug to 2000 ug. 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 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 two-way 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 than was a slight modification of that used by the fourth operator. It was not determined whether this modification accounted for the observed operator effect.To provide data regarding the role of extraction and ASV measurement in the low recoveries, the lead concentrations of a limited number of UE extracts were analyzed using inductively coupled plasma (ICP) atomic emission spectrometry. A key finding was that wipe type had an effect on lead recovery when determined using either ICP or ASV analyses of the UE extract solutions. In addition, one wipe may have produced an interferant(s) to ASV analysis.Based on the study results, a main conclusion is that the UE/ASV test procedure lacked robustness for analyzing dust wipe specimens. That is, it was found that changes in the experimental variables incorporated in the study design could lead to low lead recoveries. Future investigations should address improving robustness.
analysis, anodic stripping voltammetry (ASV), building technology, dust wipes, lead recovery, lead-containing dust, operator effect, testing, ultrasonic extraction (UE)
, Toman, B.
, McKnight, M.
, Emenanjo, I.
and Baghai, M.
Ultrasonic Extraction/Anodic Stripping Voltammetry for Determining Lead in Dust: A Laboratory Evaluation, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860504
(Accessed May 28, 2023)