LEAD DETERMINATION IN GASOLINE BY IODINE CHLORIDE (ICI) METHOD: ASTM D3341
(Equivalent Test Methods: IP 270, ISO 3830, DIN 51769 T2, and JIS K 2255)
EXPLANATION
This test method is applicable in the range 0.026 to 1.3 g Pb/L.
TEST SUMMARY
A known volume of the sample is diluted with heavy distillate, and shaken with aqueous iodine monochloride reagent. Thus, any tetraalkyl lead compounds present convert to dialkyl lead compounds and are extracted into the aqueous phase. The separated aqueous extract is evaporated to low volume to decompose free iodine mono-chloride. Any organic matter present is removed by oxidation with nitric acid, which also converts dialkyl lead compounds to inorganic lead compounds. The residue is dissolved in water and buffered at pH 5. The lead content of this solution is determined by titrating with EDTA using xylenol orange as an indicator.
TEST PRECISION
This test method has a repeatability of 0.00365 + 0.0073X and a reproducibility of 0.0135 + 0.027X where X is the average result in g lead/L at 15.5° C.
The bias of this test method has not been determined due to lack of cooperators.
