Abstract
A method for the direct determination of low Cd levels in crude oil and oil products was described. By use of a Perkin-Elmer 5000-Z with HGA 500, L''vov-platform and O2 ashing, detection limits of < 0.06 .mu.g Cd/l for crude oils and < 0.03 .mu.g Cd/l for diesel and carburetor fuels were achieved. The temperature program required for optimal results was described and its evaluation discussed. The day-to-day precision for 0.3 .mu.g Cd/l was .+-. 12%; the accuracy of the results, at least for samples with higher Cd levels, was confirmed by comparison with DPASV [differential pulse anodic stripping voltammetry] after wet digestion and with GFAAS [graphite furnace atomic absorption spectrometry] after extraction with dilute HNO3. Different evaluation modes were applied and compared. The Cd contents found in various oils and oil products showed that a noticeable Cd contamination of the environment by combustion of crude oil and fuels was not found.