Lead Traces in Nonleaded Automotive Fuels - Critical Comparison of Test Methods.

The German standard test method for unleaded gasolines, DIN 51 607, specifies as upper limit a concentration of max. 0. 01 g/l Pb. Pending the new issue of the DIN 51 769, part 8, based on the first results of the new series of round robin tests, the precision data for the range of mass concentration 7 to 25 mg/l Pb must be handled as follows: repeatability r equals 2 mg/l Pb, reproducibility R equals 3 mg/l Pb. For a further reduction of the prescribed maximum lead concentration to 5 mg or 1 mg lead per liter gasoline - should this be legally forced by the German or European government some future date - this concentration range can be determined with a good repeatability by a graphite furnace atomic absorption spectrometry method in the addition mode.