Ferrous thiocyanate

Eisen-reihe, /. iron aeries, -refin, -resinit, m. (Min.) humboldtine. -rhodanid, n. ferric thiocyanate, iron(III) thiocyanate, -rho-daniir, n. ferrous thiocyanate. iron(II) thiocyanate. -rogenstein, m. oolitic iron ore. -rohr, n., -rohre, /. iron pipe or tube, -rost, m. iron rust, -rostwasser, n. iron liquor, iron mordant, -rot, n. colcothar. -safraQt m. saffron (or crocus) of Mars, -salmiak, m. (Pharm.) ammoniated iron, iron and ammonium chloride, -salz, n. iron salt, -sand, m. ferruginous sand, -sau, /. iron sow. 

Synonyms ferrous thiocyanate ferrous sulfocyanate ferrous sulfocyanide... 

Chloroprene Peroxide. The efficiency of conversion of oxygen to total peroxides and hydroperoxide at various extents of oxidation was determined by iodometric methods. At up to 12% oxidation the proportion of hydroperoxide was constant at 20% of the whole. Ferrous thiocyanate likewise estimated a constant proportion (40%) of the total peroxide. Direct analysis of oxidates was somewhat difficult since the chloroprene tended to continue oxidizing during manipulation. Total peroxide estimates on chloroprene-free solutions of peroxide in toluene showed that at 20% oxidation 84% of the oxygen absorbed was present as peroxide groups. This is a minimum value since a small amount of the peroxide may have decomposed while chloroprene was being removed at —20°C. 

Tetrapyridino-ferrous Thiocyanate, [Fe(C H5N)4](SCN)2, is produced when a concentrated solution of ammonium thiocyanate is mixed with the chloride described above. It separates as a yellow powder. 

Ferrous thiocyanate A 2 3 mixture of a 4% aqueous ferrous sulfate and 1.3% acetone solution of ammonium thiocyanate is sprayed on the plate yielding red-brown spots. 

Ferrous thiocyanate, Fe(CNS)2.3H20, is obtained by dissolving iron in an aqueous solution of the free acid. It crystallises m monoclinic prisms, and is readily oxidised by exposure to air.4... 

Oxides and peroxides can occur in many essential oils by a photochemical reaction. 1,8-Cineol and linalool monoxide can be readily separated on silica gel thin layers with 1-nitropropane-hexane (1 1, v/v), as the mobile phase.In this case, they have exhibited Rf values of 73 and 8, respectively. " Another pair of compounds, ascaridole and 1,8-cineol, can be easily separated on a silica gel layer, obtaining a value for chloroform as the mobile phase of 63 and 54, respectively. The antimony chloride reagent gives a gray color. The potassium iodide-acetic acid-starch test is usually better than ferrous thiocyanate. 

Detecting peroxides. There may be times when you need to know the peroxide content of a chemical and there are several methods that test for the presence of peroxides, including iodide methods, ferrous thiocyanate methods, titanium sulfate methods, and test strip methods. These methods each have their limitations—some will not detect the presence of all peroxide forms. These methods should not be used to test alkali metals or amides since they react violently with water. Test strips offer some advantages in that they detect a wide group of different peroxides, can be used easily, and are convenient. However, they have limited shelf life and may be beyond the budget of some. For example, potassium iodide-starch test strips are available that can detect peroxides below 100 ppm. The presence of peroxides is detected by deep dark blue (virtually black) color on the test strip from the reaction of iodine (from potassium iodide reaction with peroxide) and starch. We will not discuss these peroxide test methods in detail here, but you should know that they are available. 

Oxides and peroxides can be visualised with the usual reagents (Nos. 11, 15, 18) or with an acidic p-dimethylaminobenzaldehyde solution (No. 70). The iodide-acetic acid-starch test (Rgt. No. 139) has usually been better than the ferrous thiocyanate reagent (No. 115) as a more specific test for peroxides (cf. also Knappe and Peteri [133]). 

Middleton and Hymas summarised all previous tests proposed for the detection of peroxides present in the quantities usually met with in anaesthetic ether and studied their relative values for experimental work. The sensitivities of twenty different methods were compared both for hydrogen peroxide and ether peroxide. As the best quantitative method would be that in which the intensity of colour is most nearly proportional to the amount of peroxide present, and observable over a wide range, the ferrous thiocyanate method (sensitive to 0-017 p.p.m. ether peroxide and 0-025 p.p.m. hydrogen peroxide) was eventually chosen as most suitable. 

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