Which method is typically the most sensitive for trace lead analysis?

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Detecting trace amounts of lead hinges on concentrating the analyte in the measurement area and minimizing background signals. Graphite furnace atomic absorption spectrometry achieves this by depositing a tiny amount of sample in a small graphite tube and then heating it through drying, charring, and atomization. This electrothermal approach concentrates lead in a very small volume and sustains atomization long enough to produce a strong, easily measurable signal, while also helping to suppress matrix interferences. The result is a much lower detection limit compared with other common methods.

Flame atomic absorption uses a larger flame for atomization, with a shorter residence time and more background noise, which reduces sensitivity. Inductively coupled plasma optical emission spectrometry analyzes light emitted from a high-temperature plasma and is excellent for multi-element analysis, but its detection limits for a single trace element like lead are typically not as low as those achieved with a graphite furnace. Graphite furnace AAS uses the same principle of atomic absorption but with the enhanced sensitivity gained from the furnace preconcentration and precise control, making it the most sensitive option for trace lead analysis.