Ultrasonic Extraction/Anodic Stripping Voltammetry for Determining Lead in Dust: A Laboratory Evaluation.
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.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899