[Importance of determination of individual hematocrit in the assessment of protoporphyrin IX in erythrocytes using a commercial hematofluorometer (Buchler ZF)].
The erythrocyte content of protoporphyrin IX was measured in a group of 191 battery plant workers. According to the results of biological monitoring the selected workers had increased occupational exposure to lead. Measurements were done with a commercial haematofluorometer Buchler ZF which was calibrated to the average haematocrit value of 0.42. The values measured were then corrected to individual haematocrit values. Haematocrit was determined in the standard manner and the individual values ranged from 0.38 to 0.51. Test results showed a major difference in protoporphyrin IX concentrations directly determined with a haematofluorometer and the ones calculated by correcting to the individual haematocrit.