mental contamination and the resulting unacceptable rate of false positives. When the blood is collected, from either a fingerstick or venous, the hands or the arm of the child or adult must be properly washed, and the person collecting the specimen should be wearing powder-free gloves.
There are two main analytical procedures for analyzing the blood, Anodic Stripping Voltammetry (ASV) or Graphite Furnace Atomic Absorption Spectroscopy (GFAAS). GFAAS has been vastly improved by the development of new instruments with microprocessor control; user-friendly, windowed software; capability for automated operation; improved background correction; and improved tube heating. Instruments that use ASV have also been improved, such as the ESA model 3010B, which is easier to use and is more precise and accurate, with lower detection limits than its predecessor. Several key factors should be examined in selecting the appropriate analytical method for your application. These include (but are not limited to): budget, personnel (availability, background, and experience), existing computer climate, throughput (the number of specimens to be processed and reported per unit of time), the need to analyze for elements other than lead, specimen volume available, specimen matrix, and available bench space. Other issues that influence the decision on the analytical method or the instrument manufacturer is the availability of parts and service personnel. Budget considerations are that ASV instruments cost on the order of US$15,000 per unit, and you MUST purchase the reagents from the instrument manufacturer. GFAAS instruments cost US$30,000–60,000 per instrument. Therefore, ASV has a lower initial cost, but has higher reagent costs; GFAAS has a higher initial cost, but lower reagent and gas costs. ASV is manual operation only, whereas GFAAS is normally automated.
Another consideration in determining the method to use is whether there will be totally centralized testing or distributed testing. the ASV instrument is capable of being set up at various sites, whereas the GFAAS instrument is not capable of being moved to multiple locations. The need for a steady supply of Ar gas for the GFAAS is also a consideration.
A supply of “lead-free” reagents and supplies (water, sample cups, pipets, standards, acids, and the like) must be obtained.
A critical component of any blood lead laboratory is the quality assurance (QA) and quality control (QC). Various well-established reference laboratories recommend that the instrument standards be NIST (National Institute of Standards and Technology) traceable. The instrument should be calibrated using multiple standards that cover the appropriate analytical