Ferric acetates ferrocyanid

Peptones.—Very soluble in water, not coagulated by heat. Are not precipitated by potassium ferrocyanid in the p resence of acetic acid, by NaCl in excess in presence of an acid, by HNOa, or by boiling with ferric acetate. 

Ferri- and ferrocyanides - 401, 408 Ferric acetate - 171, 193, 266 Ferric acid salts - 60, 149, 392 Ferric ammonium sulfate - 19, 231, 660 Ferric-chlorate ion - 384... 

Chemical complexes of various transition metals have been shown to promote N-nitrosation (28). These metal complexes include ferrocyanide, ferricyanide, cupric ion, molybate ion, cobalt species, and mercuric acetate. All of the reactions are thought to proceed by oxidation-reduction mechanisms. However, such promotion may not be characteristic of transition metal complexes in general, since ferricyanide ion has been shown to promote nitrosation in metalworking fluids, whereas ferric EDTA does not (2 0). Since the metalworking operation generates metal chips and fines which build up in the fluids, this reaction could be of significance in the promotion of nitrosamine formation in water-based metalworking fluids. 

The acid filtrate is treated with excess of ammonium chloride and with ammonia to precipitate the ferric oxide and any alumina, the precipitate being tested for the latter in the usual way. The filtrate is divided into three parts one is acidified with acetic acid and tested for copper with ferrocyanide in another the manganese (if present) is precipitated with ammonium sulphide, lime and magnesia being then tested for in the third sulphates are tested for with barium chloride. Manganese is best sought in a separate portion of the substance by the well-known dry reaction. 

Copper, Nitric Acid, etc. (Alkali Salts, Calcium). — Dilute 20 iM. of ferric chloride solution (1 1) with 100 cc. of water, fuld 25 cc. of ammonia water, and filter. On evaporating 50 cc. of the colorless filtrate and igniting the residue, the weight of the latter should not exceed 0.001 gm. On mixing 2 cc. of the filtrate with 2 cc. of concentrated sulphuric acid, and overlaying tliis mixture with 1 cc. of ferrous sulphate solution, no brown zone should form at the contact-surfaces of the two licpiids. 20 cc. of the filtrate acidulated With acetic a

potassium ferrocyanide solution. 

Gradual. Lead acetate, sulphur Temporary. Many dyes and pigments, i.e. Cl acid yellow 1, Cl acid red 33, Cl acid brown 19, Cl basic blue 99, ferric ferrocyanide... 

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