ASTM D5799 Standard Test Method for Determination of Peroxides in Butadiene
9. Calculation
9.1 Calculate the peroxide content as follows:
peroxide, as O2, ppmw = [(A - B) x N x 16 000]/W
where:
A = Na2S2O3 solution required for titration of the sample, mL,
B = Na2S2O3 solution required for titration of the blank, mL,
N = normality of the Na2S2O3 solution,
W = sample weight, g, and
16 000 = milliequivalents of oxygen.
10. Precision and Bias
10.1 Precision - The precision of this test method as determined by statistical examination of interlaboratory results is as follows:
10.1.1 Repeatability - The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would, in the long run, in the normal and correct operation of the test method, exceed the following values only in one case of twenty:
R = 1.4 ppmw
10.1.2 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 and in the normal and correct operation of the test method, exceed the following values only in one case in twenty.
R = 3.4 ppmw
10.2 Bias - As no reliable source of butadiene polyperoxide is available, the actual bias of the test method is unknown; but published data reports that this test method determines 90 % of the polyperoxide.
11. Keywords
11.1 butadiene; butadiene polyperoxide; peroxide
