DIN 51769-9 Testing of petroleum products; determination of the lead content (total lead) of liquid mineral oil hydrocarbons with a mass fraction of lead of 50 to 1000 µg/kg; iodine monochlorid disentegratien; extraction with dithizone and photometric determination of the lead dithizone complex

standard by Deutsches Institut Fur Normung E.V. (German National Standard), 10/01/1981