Crude fat, diethyl ether extraction, in feed, cereal grain, and forage (Randall/Soxtec/submersion method): collaborative study.
A method for determining crude fat in animal feed, cereal grain, and forage (plant tissue) was collaboratively studied. Crude fat was extracted from the animal feed, cereal grain, or forage material with diethyl ether by the Randall method, also called the Soxtec method or the submersion method. The proposed submersion method considerably decreases the extraction time required to complete a batch of samples. The increase in throughput is very desirable in the quest for faster turnaround times and the greater efficiency in the use of labor. In addition, this method provides for reclamation of the solvent as a step of the method. The submersion method for fat extraction was previously studied for meat and meat products and was accepted as AOAC Official Method 991.36. Fourteen blind samples were sent to 12 collaborators in the United States, Sweden, Canada, and Germany. The within-laboratory relative standard deviation (repeatability) ranged from 1.09 to 9.26% for crude fat. Among-laboratory (including within) relative standard deviation (reproducibility) ranged from 1.0 to 21.0%. The method is recommended for Official First Action.
Thiex
Nancy J
NJ
South Dakota State University, Oscar E. Olson Biochemistry Laboratories, Box 2170, ASC 151, Brookings, SD 57007, USA. nancy_thiex@sdstate.edu
Anderson
Shirley
S
Gildemeister
Bryan
B
D000821:Animal Feed / Q000032:analysis*; D004041:Dietary Fats / Q000032:analysis*; D002523:Edible Grain / Q000737:chemistry*; D004986:Ether; D005504:Food Analysis / Q000379:methods* / Q000592:standards; D007753:Laboratories; D010936:Plant Extracts / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D004041:Dietary Fats; D010936:Plant Extracts; D004986:Ether