scope:

This document is intended for use by members of the clinical laboratory testing community involved in the collection and measurement of lead in blood and urine. A background section on the clinical significance of lead concentration measurements is included to help laboratorians and others understand the context in which these measurements are made. Sample collection and measurement by the three principal measurement procedures currently in routine use are included and listed below.

1. Electrothermal atomic absorption spectrometry (ETAAS), also widely known as graphite furnace atomic absorption spectrometry (GFAAS). Instrumentation for GFAAS is available from many commercial sources. Because instruments vary significantly among manufacturers, a generic measurement procedure is described in some detail.

2. Anodic stripping voltammetry (ASV). Commercial ASV instrumentation specifically for blood lead (BPb) concentration measurement is currently available from a single manufacturer. A detailed ASV procedure, which includes use of a proprietary reagent, is provided by the manufacturer. Details of the commercial ASV method are not duplicated here; rather, the procedure is summarized, and specific recommendations are given that can help with troubleshooting performance problems.

3. Inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS is increasingly used for lead and trace element analysis. It is particularly useful for measuring low lead concentrations (< 10 μg/dL [0.48 μmol/L]), because the newer literature suggests that lead concentrations of < 10 μg/dL (0.48 μmol/L) have detrimental effects, and the reference level for BPb in children has been lowered to 5 μg/dL (0.24 μmol/L). ICP-MS is more sensitive than GFAAS and ASV. Because there are significant variations among makes and models of ICP-MS instrumentation, some general information and recommendations on sample preparation and analysis by ICP-MS are provided.

The document also includes guidelines for QA and QC, and information on proficiency testing (PT) programs and laboratory certification.

The analyst is free to choose which technique best suits the laboratory's needs, and may modify the recommended procedure to achieve accurate and precise results that meet scientific and regulatory requirements. However, whether following the recommended procedure or a modified version, the analyst is responsible for ensuring that the procedure adopted in the laboratory is validated per the laboratory's needs and any applicable regulations.