Rosaniline reagent

Add 2.5 mL of rosaniline reagent to each of four test tubes labeled blank, no. 1, no. 2, and no. 3. To these test tubes, add the sample and blank you prepared in Part A using the following scheme ... 

Rosaniline reagent place 100 mg p-r os aniline HC1 (Allied Chem. Corp.) and 200 mL water in a 1-L volumetric flask. Add 80 mL concentrated HC1 (12 M HC1) to 80 mL ice cold water in a 250-mL beaker. Stir. Add the hydrochloric acid solution to the 1-L volumetric flask, mix and add enough water to bring to volume. The rosaniline reagent must stand at least 12 hr. before use. Follow the safety precautions given above in this preparation. 

Bromide ions are oxidized in slightly acidic media with hypochlorite to bromate. The excess of the h)q)ochlorite is taken away by reacting it with sodium formate, and bromide ions are added in excess. The reaction between the bromate and the bromide results in bromine (amplification). The bromine is reacted with the rosaniline reagent (basic fuchsin). The product of this reaction is dissolved in butanol, and the absorbance is measured at 573 mn. 

Sohiff s Rosaniline Reagent, 1 per cent, rosaniline decolourised by SO2. General reagent for free aldehyde groups. 

SchifT s reagent A solution of rosaniline in water decolorized with sulphurous acid. Aliphatic aldehydes and aldose sugars give a magenta colour with this reagent with aromatic aldehydes and aliphatic ketones the colour develops more slowly aromatic ketones do not react. 

Schiff s Reagent. Dissolve 1 g. of rosaniline in 50 ml. of water with gentle warming. Cool, saturate with SO, add about i g. of animal charcoal, shake and filter make up to i litre with water. If the pink colour reappears on standing, add a few drops of SOj-water carefully with stirring until the colour Just disappears. 

Schiff s reagent is a dilute solution of fuchsin hydrochloride (p-rosaniline) that has been decolourised by sulphur dioxide. This decolourisation is the result of a... 

Preparation of SchlfT s reagent. Method 1. Dissolve 0- 2 g. of pure p.rosaniline hydrochloride in 20 ml. of a cold, freshly-prepared, saturated aqueous solution of sulphur dioxide allow the solution to stand for a few hours until it becomes colourless or pale yellow. Dilute the solution to 200 ml. and keep it in a tightly, stoppered bottle. If the bottle is not adequately stoppered, the reagent will gradually lose sulphur dioxide and the colour wUl return. The solution keeps well if not unnecessarily exposed to light and air. 

Schiff s reagent analy chem An aqueous solution of rosaniline and sulfurous add used in the Schiff test. shifs re,a-(3nt ... 

The determination of formaldehyde, a substance of great interest on account of its toxicity and high significance to the resin, fertilizer and explosive manufacturing industries, among others, entails the use of rapid, convenient, safe methods. One sensor developed for this purpose uses the manifold shown in Fig. 4.6 to handle the reagents involved, viz. / -rosaniline (PRA) and sulphite. The instability of sulphite ion calls for on-line mixing with PRA dissolved in 0.4 M HCl prior to injection of the sample. After the... 

A more general method for carbohydrates that can be used equally well on handsections and on sections of plastic embedded materials uses the Periodic acid SchifFs (PAS) reaction or one of its variants [29] for vicinal hydroxyl groups [22,23]. Sections are treated with 1%W/V Periodic acid at room temperature for 10 minutes and rinsed. The aldehydes created by this treatment are detected with SchifFs reagent (decolorized para-rosaniline) by immersion for 30 minutes. A red color (or fluorescence with excitation at 540 nm) indicates vicinal hydroxyl groups in starch and many other carbohydrates. If the specimen has been fixed with aldehydes then an aldehyde-blocking step must precede this reaction [22]. The best treatment is immersion for 24 hr in a saturated solution of dimedone. 

SchifPs Reagent, Modified Dissolve 200 mg of rosaniline hydrochloride (C20H20CIN3) in 120 mL of hot water. Cool, add 2 g of sodium bisulfite (NaHS03) followed by 2 mL of hydrochloric acid, and dilute to 200 mL with water. Store in a brown bottle at 15° or lower. 

Schiff s reagent is prepared by dissolving 0.1 g Basic Fuchsin (p-rosaniline hydrochloride) in too mL of water and then adding 4 mL of a saturated aqueous solution of sodium bisulfite. After I h add 2 mL of concentrated hydrochloric acid. 

Sduff s fuchsin aldehyde reagent. Dissolve 1 g of fuchsin (p-rosaniline hydrochloride) in 200 ml of water, with gentle warming. Cool and saturate with sulfur dioxide. Allow to stand for several hours. Add 1 g of decolorizing carbon, shake, filter, and dilute with water to 1 liter. 

Dissolve about 0.2 gram of rosaniline in a small amount of boiling water. Cool and add 15 cc. of a saturated solution of sulphur dioxide in water, and allow the mixture to stand several hours until it becomes colorless or pale yellow then dilute to 200 cc. with water. The reagent should be kept in a well-stoppered bottle of dark glass. 

To one such slide, a tissue dampened with 0.1 N HCl, 2% starch and 10% potassium iodide solution (made fresh daily) is applied. A weak color reaction, which is much stronger at the locations of charcoal flecks and any white droplets are potassium oxides and carbonate. A tissue overlay of hexamethylene rosaniline hydrochloride (crystal violet) is applied to another fresh slide. Bleaching and pH effects are observed. Other pH indicators and other peroxide sensitive solutions should be applied. The author finds that thickening the reagents with carbohydrate and polyvinyl alcohol to slow diffusion rates is advisable in some cases. 

Schiff s reagent is an aqueous solution formed by combining p-rosaniline hydrochloride (basic fuchsin), sodium bisulfite, and concentrated hydrochloric acid (Eq. 25.10). The reagent reacts with aldehydes to produce an imine, also called a Schiff base, that is magenta or purple in color (Eq. 25.11). The mechanism for forming the addition product presumably involves nucleophilic attack of sulfur on the aldehydic carbonyl group. 

If Schiff s reagent is not available as a stock solution, prepare it by dissolving 0.01 g of p-rosaniline hydrochloride in 10 mL of water, adding 0.4 mL of saturated aqueous sodium bisulfite, and allowing the resulting solution to stand for 1 h. Then add 0.2 mL of concentrated hydrochloric acid to complete the preparation. 

Basic potassium hypochlorite solution about 1.1 M for KCX31 and 0.08 M for KOH Acidic rosaniline— potassium bromide reagent... 

The Fuchsin Aldehyde. Te.sL —Ald( hyd( s restort color to Fuchsin Aldehyde Reagent wIktcms lo tones do not. riu reagent is a dilute solution of rosaniline or fuchsin hydrochloride ( inag( tit,a) that has been decolorized by sulfur dioxide. ... 

Feulgen s Test for Nucleic Acid.—The material is hydrolysed with N/10 HCl at 60° C. for four minutes, and then treat with Schifi s aldehyde reagent (a 1 per cent, solution of rosaniline decolorised with SO2), a red colour develops if animal or thjmio-nucleic acid be present. The test depends on the presence of desoxyribose. 

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