It is possible to decrease the amount of sample used in K-TDFR assay, but the volumes of all the reagents used in the assay must remain the same as described in the data booklet.

The smallest weight of sample we have used in this analysis is 0.1 g. 
Please refer to a table on page 6 of K-TDFR data booklet.

Total Dietary Fiber (K-TDFR) Data Booklet

When selecting a sample size to use for small quantity samples, please remember that samples should be analysed in duplicate (one replicate to determine protein, one to determine ash).