Spectrophotometric determination of sulfites, benzoates, sorbates, ascorbates, and added blood in ground beef:...

A method for the determination of sulfite, benzoate, sorbate, ascorbic acid, and added blood in ground beef reported previously was studied collaboratively. Eleven laboratories reported results on 18 samples analyzed for the preservatives plus 6 samples analyzed for added blood. Average recoveries for sulfite added at the 0.02 and 0.04% levels were 44.3 and 70.6%, respectively; average recoveries for benzoate at 0.02 and 0.05% were 83.5 and 85.9%; average recoveries for sorbate at 0.01 and 0.02% were 82.7 and 87.3%; average recoveries for ascorbic acid at 0.02 and 0.04% were 71.0 and 69.8%. Only 5 of the 11 collaborators reported accurate results on the 6 samples for added blood, and further study of this procedure is recommended. The preservative method has been adopted as official first action.