Contributions to automated trace analysis. Part II. Rapid method for the automated determination of lead in whole blood by electrothermal atomic-absorption spectrophotometry
A simple, rapid method is described for the determination of lead in whole blood by means of electrothermal atomic-absorption spectrophotometry. Aliquots (25–200 µl) of fingerprick and venous samples were treated with 2 M nitric acid for deproteinisation and matrix modification. After centrifuging, the supernatant was taken for the automated analysis for lead. The accuracy of the method was checked with independent methods and found to be satisfactory. Thus it was established that the accuracy obtainable of ⩽30% lies almost within the confidence intervals (p= 0.05) of precision. An evaluation of 282 pairs of randomly selected routine samples indicated an acceptable precision: the relative standard deviation for, for example, the normal level of 100 µg l–1 is 8.4%, and for an elevated level of 480 µg l–1 is 3.47%. The shortened temperature programme makes up to 370 measurements per day possible and the computer coupling permits an immediate data evaluation during occupational and screening programmes and makes possible round-the-clock measurements.