Determination of Nickel in Hydrogenated Fats by Neutron Activation Analysis.

Determination of Copper in Hydrogenated Fats by Neutron Activation Analysis.

“…In view of the work of Souliotis on the determination of nickel in hydrogenated fats (7) and that of Bruñe (4) on the application of the Szilard-Chalmers effect in the neutron activation analysis of biological samples, it was not surprising that it was possible to extract the induced copper activity with 6N hydrochloric acid from a toluene solution of the irradiated fat. Although this most probably can be fully ascribed to copper existing in the nonirradiated fat as simple ions or organic complexes which are readily extractable in 6N hydro-chloric acid, it is possible that part of the radioactive copper is extracted due to a Szilard-Chalmers effect on copper (which is nonextractable in nonirradiated fat), or that radioactive copper, still bound owing to recombination, is extracted through isotope exchange with the copper carrier (4).…”

“…Recently, a procedure was published for the determination of nickel in hydrogenated fats using neutron activation analysis (7). The induced nickel activity was extracted with nitric acid from a toluene solution of the fat.…”

Estimation of Residual Nickel and Some Heavy Metals in Vanaspati Ghee

“…The original method of Price used carbon tetrachloride as organic solvent, 3 while Souliotis substituted benzene. 9 In this regard, using different acidic mixtures, the extraction of nickel was checked using organic solvents such as toluene, carbon tetrachloride and benzene. 2 Keeping in view our past experience, toluene was used as organic solvent in the present work.…”

“…To a 30 g sample of pure animal fat, various amounts of nickel catalysts were added for the percent recovery of nickel by different methods. 6,9 Each sample was heated up to 200°C so that the nickel catalyst may be thermally decomposed to metallic nickel. The extraction of nickel was carried out by different methods.…”

“…0.008 and 0.17 parts/100, respectively. [9][10][11] It is also clear from the results of different extraction methods that a 20% acid mixture of both H 2 SO 4 and HNO 3 is more effective than concentrated acids for the same purpose. Residual nickel in hydrogenated vegetable oils has also been investigated by other workers but all these methods are tedious, time consuming and are not efficient in extracting the maximum amount of residual nickel, e.g.…”