Combination of Catalysts in the Determination of Nitrogen: III. Meat Products

Pharmaceuticals and Natural Drugs

“…GENERAL Reports of the various methods for determining aldehy'des (109) particularly in volatile oils, acetaldehyde, and acetone (247), and the chemical characteristics of aerosporin (43,131) and the determination of arginase (212), tryptophan (242), ßglucuronidase (165), and nitrogen (279) content of proteins are all to be found in very recent publications. The effects of various catalysts and modifications of the original Kjeldahl method for the determination of nitrogen (114,180,199) are also discussed.…”

Fertilizers

“…Much attention has recently been given to the use of selenium and its compounds (24,48,55,62,130,131,136,184,109,202,205,206,211,226,258), alone or in combination with other catalysts, which effect more rapid oxidation of the organic matter and shorten the digestion time but may cause some loss of nitrogen if the digestion is unduly prolonged (62,202). Better recovery of the nitrogen is said to be obtained with combinations of selenium and mercuric oxide (55, 202), and the selenates of copper, cadmium, and calcium, in the decreasing order, are reported to be more efficient than elemental selenium (62).…”

“…Sarudi (246) proposes digestion of the sample with sulfuric acid and 30% hydrogen peroxide without addition of a metal catalyst and alkali sulfate-a rapid procedure which, with certain modification (159), is said to give results in agreement with those obtained by the standard methods. Poe and Lane (211) report that use of hydrogen peroxide in connection with a mercuric oxide-selenium-copper sulfate catalyst further reduces the digestion time, but probably not enough to justify the additional trouble and expense. Other aids to the sulfuric acid digestion include potassium persulfate (17,130), phosphoric acid (17,211).…”

“…Poe and Lane (211) report that use of hydrogen peroxide in connection with a mercuric oxide-selenium-copper sulfate catalyst further reduces the digestion time, but probably not enough to justify the additional trouble and expense. Other aids to the sulfuric acid digestion include potassium persulfate (17,130), phosphoric acid (17,211). dipotassium phosphate (211), and mixtures of dipotassium phosphate and ferric sulfate (216).…”

“…Other aids to the sulfuric acid digestion include potassium persulfate (17,130), phosphoric acid (17,211). dipotassium phosphate (211), and mixtures of dipotassium phosphate and ferric sulfate (216).…”