The raw linseed oil acetone foots test. I. A centrifuge tube and method for rapid determination

Summary A rapid method, requiring less than one hour to apply, has been developed for determining the acetone foots content of linseed oils using centrifugal force to compact the foots layer instead of the force of gravity. Application of the method requires the use of a centrifuge tube of novel design. Conditions known to affect the results obtained by the A.S.T.M. gravity test have been investigated as they apply to the centrifuge test and found to have little or no effect on the results of the latter test. Correlation of the percentage of centrifugal foots under stated conditions with percentage of foots by the gravity method has been determined for both the heated and chilled tests. Under the conditions chosen for the centrifugal test the magnitude of the heated test result is about the same as the processing shrink sustained when these foots are removed in practice. The reproducibility of the method, based on this work, is equal to or better than the gravity test now in use for trading linseed oil. A modification of this test has been developed specifically for use on crude soybean oil and a paper describing it is in preparation.