Nonrubber Components of Ammonia-Preserved Latex. An Analytical Study

Analyses of ammonia-preserved latex concentrates have been made in order to study some of the main features of composition of the nonrubber material at the time of using the latex, usually about three months after tapping on the plantations. The information thus obtained is supplementary to corresponding work carried out on fresh latex in Malaya. Latex, at the stage now being considered, contains no phospholipin as such; but its decomposition products, ammonium soaps, free choline, and combined phosphate (probably glycerophosphate) are found. There is protein in the serum and at the rubber interface, a small amount of free amino acid, and probably also substances of a polypeptide nature. The serum contains salts of volatile and nonvolatile acids, in some cases as ammonium salts, and also a considerable amount of quebrachitol. The rubber phase contains phytosteryl esters. From the analyses of an electrodecanted and a centrifuged concentrate prepared from a common field latex it is shown that the higher amounts of some, but not all, nonrubber components in the electrodecanted concentrate are in accordance with its having a smaller average rubber particle size. The excess of both protein and phospholipin breakdown products indicates the existence of a protein-phospholipin complex. Analysis of the serum remaining after electrodecantation and of the original field latex has enabled a tentative distribution of nonrubber material to be calculated between serum and rubber phases.