[Development of a method for determining lead blood levels with chronopotentiometry].

A potentiometric stripping analysis method for blood lead determination, using Radiometer Tracelab PSU 22, has been investigated. Hemoglobin precipitation by hydrochloric and perchloric acids mixture allows to obtain the same signal for the same lead concentrations in aqueous standards and various blood samples. Thus it is possible to use a time saving calibration procedure. Equilibration time increase improved method sensitivity and precision. The analysis time was 3 minutes per sample. The detection limit was 0.006 microM/L. The relative standard deviation was 3.6% for 1.351 microM/L and 6% for 0.203 microM/L. The results of 66 determinations obtained by this method and by graphite furnace atomic absorption spectrometry were compared (R=0.991). Potentiometric stripping analysis is less expensive and very convenient for clinical laboratories.