Identification Tests Nitrate

Detection and Estimation.—The decomposition of thiosulphates by means of hydrochloric acid to yield sulphur dioxide with separation of sulphur serves as a primary identification test, the limit of sensitiveness being about 0-1 mg. S203 per c.c.3 The alkali thiosulphates produce with silver nitrate solution a white precipitate of thiosulphate which gradually turns yellow, then brown, and finally black, due to the formation of sulphide the change is accelerated by warming 4... 

Bis-di(carboxymethyl)aminomethyl-o-cresolsulfonphthalein, 861 3,7-Bis(dimethylamino)phenazathionium Chloride, 860 Bismuth Nitrate TS, 850 Bisulfite Identification Test, 753 Bitter Almond Oil Free from Prussic Acid, 19... 

The BP identification tests for econazole nitrate are based on three procedures13 ... 

The selectivity of the test is quite limited, even compared to the specificity seen in the identification test for chlorides. In the identification three criteria have to be fulfilled to qualify for a positive reaction. The unknown should give a white (curdled) precipitate formed upon addition of silver nitrate, which is insoluble in dilute nitric acid but redissolves in ammonia. In the limit test 2.4.4. Chlorides any substance capable of giving a white or weakly colored precipitate in dilute nitric acid will give a response like chloride, and this should be remembered in case of an xmexpected result. For the sake of example the following ions and substances are capable of giving a false positive reaction bromide, iodide, bromate, iodate, sulfite, chlorate, oxalate, and benzoate. In addition to this a variety of more complex organic substances are likely to precipitate, for example, alkaloids. 

NGc are completely sol. For their identification, weigh 5.0 g of the filtered expl oil into a large test tube, add 50mi of 60% AcOH, stopper and shake well. Insol oily drops collecting on the bottom of the test tub° indiestbs rsscncs of nitrated polymers. In this case, decant the liquid and repeat the extraction of oil with two addnl 50-ml portions of AcOH. Wash the residue with two 50-ml portions of distd water and separate by decantation. Dissolve the residue in 30 ml of ether and add an excess of anhyd... 

B. Identification. Place ca 0.2g of material in a 5 ml beaker, add 2-3 ml distd w and stir for 5 min. Decant the liq through a filter into a small beaker, Evap this to dryness and test part of the deposit white, in the case of BkPdr) with 1 drop of 1% DPhA soln in coned H2S04, using a white porcelain spot-test plate A blue color indicates the presence of a nitrate. Place another portion of the deposit in an indenture of a white porcelain spot-test plate, add an equal amt of cryst thymol and... 

BP and EP recommend that for the bromide test, a sample solution has to be first acidified with dilute nitric acid, and silver nitrate solution is added to produce a curdled, pale yellow precipitate. This precipitate will dissolve with difficulty when suspended in a solution consisting of 2 ml of water and 1.5 ml of ammonia. Unlike BP and EP, USP employs a silver nitrate test for identification of bromide. In this test, addition of silver nitrate test solution to the solution of rocuronium bromide (1 part of rocuronium bromide in 100 parts of water) will produce a white precipitate which is insoluble in nitric acid and slightly soluble in 6N ammonium hydroxide. 

Identification A 1 10 aqueous solution gives positive tests for Potassium and Nitrate, Appendix IIIA. 

Identification A 1 5 aqueous solution is neutral to litmus and gives positive tests for Sodium and for Nitrate, Appendix MA. 

G) Identification of an Add. Obtain an unknown acid from the instructor. Determine roughly the solubility and pH. Heat about 0.1 g with alkaline permanganate (see section [C]). Test for presence of an aromatic nucleus by nitrating 0.2 g as directed on page 122. 

The counterion for imiprimine hydrochloride, chloride, is identified as part of the active ingredient. To carry out the test, the sample powder is dissolved in alcohol, and 2 N nitric acid is added along with 3 drops of a silver nitrate test solution. A white precipitate of silver chloride is formed, which dissolves upon addition of ammonium hydroxide, confirming the presence of the chloride ion. As chloride identification is used for the testing of the drug substance, it is not required for the formulated product. 

Two of the reactions of aldehyde which have been described are much used in the identification of members of this class of compounds, namely, the formation of a mirror when an ammoniacal solution of silver nitrate is gently warmed with an aldehyde, and the change of the latter to a resin when heated with a strong solution of a caustic alkali. If these reactions take place when a substance is treated as described, there is a strong probability that it is an aldehyde. Compounds other than aldehydes, however, reduce an ammoniacal solution of silver salts, and other tests should be applied in addition to the ones just given. When an aqueous solution of rosaniline, which is a red dye, is treated with a saturated solution of sulphur dioxide in water, the color is destroyed. The colorless solution, known... 

Sodium nitrate, also known as Chile saltpeter and soda niter, has a molecular formula of NaN03 Sodium nitrate is a colorless, odorless, transparent crystal. It oxidizes when exposed to air and is soluble in water. This material explodes at lOOOT, much lower than temperatures encountered in many fires. Sodium lutrate is toxic by ingestion, and has caused cancer in test animals. When used in the curing of fish and meat products, it is restricted to 100 ppm. Sodium nitrate is incompatible with ammonium nitrate and other ammonium salts. The four-digit UN identification number is 1498. Sodium nitrate is used as an antidote for cyanide poisoiung and in the curing of fish and meat. 

In the test, chloride is precipitated as silver chloride, and the precipitates reaction toward nitric acid and ammonia is used to rule out other silver precipitates. Since a very high number of elements and also organic substances give a precipitate with silver nitrate, the description below of selec-fivify is nof meanf to be conclusive. It mainly deals wito the other halogens and a few inorganic cations. Precipitation with silver nitrate is also used for the identification of iodide and bromide, and the difference between the tests of these is therefore dealf with in more detail. 

The test identifies the substance to be examined as a salt of silver (Ag+). At the present silver is referenced in only one monograph, silver nitrate. This salt is sold in sticks, called Lapis or Lapis lunaris, and is used for the treatment of warts. Silver can exist both as silver(l) and silver(ll), but since the latter is less stable, silver(I) dominates. It is a noble metal meaning that it is most stable in oxidation state 0, its metallic form. So, contrary to most metals, it does not have at tendency to be oxidized to its ionic form and thereby corrode. Silver nitrate and fluoride are soluble, while silver nitrate, acetate, and sulfate have limited solubility. All other salts are insoluble but are, however, capable of forming many soluble complexes. The insolubility of the chloride salt and its ability to form a soluble nitrate complex are useful in identification. 

For identification of ceiiuiose acetates or propionates, one can use the reaction with ianthanum nitrate. In this test, one adds one or two drops of a 50% aqueous ianthanum nitrate solution and one drop of a 0.1 N iodine solution to a small amount of the polymer sample on a spot test plate. Then a drop of concentrated ammonia is added. If cellulose acetates are present, one quickly observes a blue coloration with cellulose propionate the coloration is brown. 

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