ASTM D2710 for Bromine Index of Petroleum Hydrocarbons by Electrometric Titration
9. Calculation
9.1 Calculate the bromine index as follows:
Bromine index = [(A - B)N x 7990]/W
where:
A = millilitres of bromide-bromate solution required for titration of the sample,
B = millilitres of bromide-bromate solution required for titration of the blank,
N = normality of bromide-bromate solution, and
W = grams of sample.
10. Precision and Bias
10.1 Precision:
10.1.1 The precision of this test method as obtained by statistical examination of interlaboratory test results is as follows:
10.1.1.1 Repeatability - The difference between successive test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed 14 in only one case in twenty.
10.1.1.2 Reproducibility - The difference between two single and independent results, obtained by different operators, working in different laboratories on identical test material, would in the long run, in the normal and correct operation of the test method, exceed 118 in only one case in twenty.
10.2 Bias - The procedure in this test method has no bias because the value of bromine index can be defined only in terms of a test method.
NOTE 8 - The precision for this test method was not obtained in accordance with RR:D02-1007.
NOTE 9 - It is not known whether the precision estimates are applicable when using dichloromethane as a constituent of the titration solvent.
11. Keywords
11.1 bromide-bromate solution; bromine index; electrometric titration; hydrocarbons; petroleum
