Elimination of the matrix effect in the cold-vapor atomic absorption analysis of mercury in human hair samples.

The percent recovery of mercury from human hair digest samples, using the peak height cold-vapor atomic adsorption method is 73.0% +/- 10.3%. This value and its reproducibility are raised to 102.2% +/- 6.3% by use of peak area measurements in place of peak height. The so-called matrix effect is thus eliminated, and its origin shown to be in the slower (but still quantitative) release of mercury from biological samples. Although greater reliability is obtained using peak area, this is gained at the cost of analysis time.