lodometric determination of peroxide values in cotton seed oil, lard and butter

Abstract

The AA. determined the rates of peroxide in cotton-seed oil, lard and butter, by the processes of WHEELER (modified by STANSBY), of chlorhydric acid and of sulphuric acid, the very way STANSBY described them. Determinations were made by all three processes, making use of the same sample, numbering twelve for each. The AA. were able to draw the following conclusions with the results obtained, after submitting them to statistical analysis — Test F:

1) Analysis of variance — Test F — was performed; according to it, variance of WHEELER-STANSBY’S of sulphuric acid process, referring to lard and cotton-seed oil, may be due to chance. The same does not go for butter. But, owing to the high percentage of this variance, they are not to be recommended.

2) The most accurate process for determining the rate of peroxide in cotton-seed oil, lard, and butter, from those examined, is the one employing chlorhydric acid; it presents a lower rate of variance. STANSBY observed the opposite of this concernig fish oil.

3) WHEELER-STANSBY’s process presented high rate of variance, even when samples were aproximately of the same weight.

7) Sulphuric acid process presented higher rates of variability as compared with the other two, when concerning butter and cotton-seed oil.