Comparison of LECO FP-228 "nitrogen determinator" with AOAC copper catalyst Kjeldahl method for crude protein.

The LECO FP-228 "Nitrogen Determinator" was compared with the AOAC copper catalyst Kjeldahl method, 7.033-7.037, for the determination of crude protein in feed materials.

Quantitative analysis of cystine, methionine, lysine, and nine other amino acids by a single oxidation--4 hour hydrolysis method.

The sulfur-containing amino acids cystine and methionine play important roles in animal, especially avian, nutrition. Because these sulfur-containing amino acids are destroyed to varying extents by 6N HCl hydrolysis, oxidation and hydrolysis of cystine to cysteic acid and methionine to methionine sulfone have been widely used for determination of cystine and methionine. Lysine is considered the next limiting amino acid after the sulfur amino acids in poultry nutrition; therefore, determination of the amino acid content of rations focuses first on these 3 amino acids.

Pollution-reduced Kjeldahl method for crude protein.

Pollution from the Kjeldahl method for crude protein has been reduced by substituting a low level of copper (0.04 g CuSO4) for the mercury (0.7 g HgO) specified in the AOAC official method, 2.

The participation of the black aged in voluntary associations.

Racial differences in membership in and attendance of voluntary associations were analyzed for comparable samples of 753 black and 260 white residents of Philadelphia age 65 and over. A hypothesis suggesing aged blacks have higher rates of participation than aged whites was derived from the literature and tested by regression analysis. Potentially confounding variables, e.