Which laboratory analysis methods are commonly used to analyze wipe samples for lead?

• A. ICP-MS or AAS
• B. Gas chromatography (GC) or liquid chromatography (LC)
• C. X-ray fluorescence (XRF)
• D. UV-Vis spectroscopy

Answer: (A)

When analyzing wipe samples for lead, the goal is to convert the collected residue into a solution and measure very small amounts of lead accurately. The standard laboratory approach is to digest the wipe with acids to release the lead into solution, then quantify it with a sensitive atomic technique. ICP-MS and AAS fit this role perfectly. ICP-MS offers very low detection limits and can measure multiple elements at once, which is especially useful for environmental testing. AAS, including graphite furnace AAS for higher sensitivity, is a tried-and-true method that provides reliable lead measurements in digested solutions.

Gas chromatography and liquid chromatography are designed for separating and analyzing organic compounds, not metals in solution, so they’re not used for lead in wipe digests. X-ray fluorescence can screen surfaces for lead or analyze solid materials directly, but for wipe samples the standard practice relies on digestion and atomic spectroscopy; XRF is generally less sensitive for trace levels in digested wipes. UV-Vis spectroscopy can be used for some colorimetric lead assays, but its sensitivity and potential interferences are limitations compared with ICP-MS or AAS, making it less common for routine wipe lead analysis.