Bromcresol purple

Bromcresol purple, dibromo-o-cresol-sulfonphthalein (indicator) dissolve 0.1 g in 9.5 mL 0.02 N NaOH and dilute with water to 250 mL or, 0.1 g in 100 mL 20% alcohol pH range yellow 5.2-6.8 purple. 

The activity of enzymes in the film was estimated in the following way In order to test the activity of urease, we utilized a calorimetric assay based on urea hydrolysis the enzymatic reaction was followed at 590 nm, the suitable wavelength for bromcresol purple (Chandler 1982). Urea concentration was 1.67 ts 10 M. 

V.G. Andreou and Y.D. Clonis, A portable fiber-optic pesticide biosensor based on immobilized cholinesterase and sol-gel entrapped bromcresol purple for in-field use. Biosens. Bioelectron. 17, 61-69 (2002). 

Bromcresol purple has been suggested as showing improved specificity for albumin and less variation in colour intensity compared with bromcresol green. The dye-albumin complex shows an absorption maximum at 603 nm and the use of a reagent buffered at pH 5.2 appreciably reduces the tendency of the complex to precipitate. 

Procedure 11.6 Quantitation of albumin using bromcresol purple dye binding... 

The system discussed, commercially known as the Delvotest (9-11), utilizes a strain of stearothermophilus which grows at a very rapid rate and produces acid from the nutrients in the medium in the absence of inhibitory substances. When inhibitory substances such as the 3-lactam antibiotics are present, acid production is inhibited. By incorporating bromcresol purple in the medium, it is easy to observe acid production, a change from purple to yellow. Incubation is performed at 65 C for approximately 3 h. 

Poly- acrylamide BuOH / NH3/ Eton (7/1/2) 0.04 % bromcresol purple Benzoic acid. Sorbic acid 21... 

An ion-pairing spectrophotometric method has also been described [14]. This method involves the use of bromphenol blue, bromcresol purple, bromcresol green, bromthymol blue, or methyl orange, and extracting the ion-pair species into chloroform. The absorbance of the yellow product is determined at 420 nm. 

Standard stop bath is 28% acetic acid. A pH indicator is added, usually bromcresol purple, which is yellow below pH 5.2 and blue above pH 6.8. When the stop bath is blue, the hydrogen ion concentration is too low to be effective. Dilute acetic acid is an irritant to the skin and can cause allergic reactions and chronic bronchitis. 

Bromcresol purple, 10% solution, 9-25 g Sodium hydroxide, 1.0 g Distilled water to make 250.0 ml... 

Indicator Bromphenol blue Methyl orange Methyl red Bromcresol purple Bromthymol blue Phenol red Cresol red Thymol blue Phenolphthalein Thymolphthalein... 

F, Cl, Br, J TLC silica gel + starch binder fluorescent reagent Visual + bromcresol-purple 1-2 Mg 310)... 

In the first procedure, hyoscyamine (or atropine) can be selectively determined in the presence of scopolamine by using bromcresol purple, which forms a chloroform-extractable complex with hyoscyamine at pH 6.6. This complex is separated and measured at 420 nm. Scopolamine and the hydrolytic product tropine do not interfere. 

The first procedure can be adopted to estimate hyoscyamine content in belladonna tincture using as little as 0.1-0.2 ml of the tincture. Bromcresol purple is used at pH 6.6 and the complex formed is treated with 0.1 N NaOH and measured at 580 nm. Neither scopolamine nor tropine interferes (86). 

Bromcresol purple Dibromo-o-cresolsulfonephthalein 5.2- .8 yellow - purple Clark and Lubs... 

Fortunately we are able to replace bromphenol blue and brom-cresol purple with other sulfonephthaleins which do not show dichromatism. W. C. Harden and N. L. Drake have prepared tetrabromophenoltetrabromosulfonephthalein (tetrabrom-phenol blue) which may be used in place of bromphenol blue. Both indicators have the same transformation range (pH 3.0-4.6) with a color change from pure yellow to pure blue. Chlor-phenol red, with a color change from yellow to red, is a good substitute for bromcresol purple. 

Felton (1921) has employed a mixture of equal quantities of methyl red and bromthymol blue for the range 4.6-7.G of methyl red and bromcresol purple for the range 4. -7.0 methyl red and thymol blue for 1.2-9.0. Lizius and Evers (1922) used one part of methyl red and three of thymol blue for the region 4r-10 one of phenolphthalein with six of thymol blue for the range 8-10 one of phenolphthalein and six of thymolphthalein for 8.3-11.0 one part of tropeolin 0 with four of thymolphthalein between pH s 9-13. 

Part bromcresol purple (sodium salt) 0.1% in water 1 bromthymol blue (sodium salt) 0.1% in water 1 6.7 yelloW violet-blue Yellow-violet at pH = 6.2 violet at 6.6 blue-violet at 6.8... 

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