The use of bilirubin oxidase to remove interference by bilirubin in hydrogen peroxide/peroxidase detecting systems is hampered by its inherent "chromogen oxidase" activity (its ability to oxidize the chromogens used in the systems). This unwanted activity is greater than 99% inhibited by 0.5 mmol/L cyanide, 97% inhibited by 20 mmol/L azide. At these same concentrations, they inhibit bilirubin o...

Abstract Overexposure to food colorants above the allowed daily intake (ADI) level can provoke hyperactivity and other disturbed behaviors especially in children. Two new methods were developed separate five synthetic colorants, which Tartrazine (E102), Sunset Yellow (E110), Allura Red (E129), Carmoisine (E122), Brilliant Blue (E133). They are labeled on a large variety of commercial products E...

Azo dyes are widely used in textile, printing, cosmetic, drug and food-processing industries. They are also used extensively in laboratories as either biological stains or pH indicators. The extent of such use is related to the degree of industrialization. Since intestinal cancer is more common in highly industrialized countries, a possible connection may exist between the increase in the numbe...

Four different, well known colour reagents for iron determination were tested in a citrate buffer at pH 2.0 under the same automated standard conditions and compared with a manual reference method on human serum and plasma samples. Specific results were obtained only with the chromogen tripyridyl-s-triazine. A micromethod was developed, which is generally well suited for automated, direct serum...

A new chromogen that absorbs maximally at 329nm was frequently found in the liver oils of the freshwater fish Bagarius bagarius and Wallago attu. It was shown to be a diester of 3-hydroxyretinol. 3-Hydroxyretinol was found to be a metabolite of lutein during the biosynthesis of 3-dehydroretinol in a freshwater fish. A new method for the chemical synthesis of 3-hydroxyretinol from methyl 3-dehyd...

In this study we have reported a new, fast and extraction free spectrophotometric procedure for the assessment of caroverine in pharmaceutical raw and tablet dosage forms. In the reported visible spectrophotometric procedure tungstate in Folin-Ciocalteu phenol reagent is reduced in alkaline medium and produces the blue colored chromogen that shows Λmax at 740nm with the calibration range of 2-2...

A new, precise, and accurate procedure is described for the automated determination of serum alkaline phosphatase on the Robot Chemist. The substrate, p-nitrophenylphosphate in 2-amino-2-methyl-1-propanol, offers the prime advantage of providing directly its own chromogen, p-nitrophenol, following enzyme action. Other advantages are the small sample volumes required and linear reaction rates. C...

We use bilirubin oxidase (EC 1.3.3.5) to remove interference by bilirubin in the assay of cholesterol concentration in bile by standard enzymatic methods. Samples are treated for 10 min with nonlimiting amounts of bilirubin oxidase to form biliverdin from bilirubin before the reagent for cholesterol is added. The relatively small interference by biliverdin is easily eliminated by use of sample ...

Certain diagnostic kits that measure serum urate by the Barham and Trinder principle of enzymic liberation of oxygen and its combination with chromogens can give results for urate in fresh serum that are approximately 20% lower than results from serum stored at ambient temperature for 72 h. In fresh serum, antioxidants compete with chromogen for liberated peroxyl-oxygen. We postulate that durin...

It can be demonstrated by an indicator method that living cells are as freely permeable to oxygen as dead cells, and that sudden admission of oxygen to the cell cannot account for increased oxidation as a result of stimulation. Oxygen penetrates as readily as carbon dioxide among the acids and ammonia among the alkalies. Exposure of living plant cells to high oxygen pressures does not initiate ...