Spectrophotometric Determination of 1-Naphthol in 2-Naphthol Utilizing Difference in Reaction Rates

Purification and biochemical characterization of the carbamate hydrolase from Pseudomonas sp. 50432

“…Routine measurement of the hydrolase activity was performed spectrophotometrically by monitoring the concentration of 1‐naphthol, which was produced during the hydrolysis of carbaryl at 25 °C in a reaction volume of 1 ml. 1‐Naphthol forms a soluble complex with diazonium dye [Fast Blue RR salt (4‐benzoylamino‐2,5‐dimethoxy benzene–diazonium chloride hemi ZnCl 2 salt)], which was colorimetrically measured at 600 nm [23,24]. The standard enzyme reaction contained 2 mM carbaryl (dissolved in chloroform), 1 mg of the dye and 50–200 μg of the enzyme preparation in 10 mM K 2 HPO 4 (pH 7.5).…”

Optimization of trichloroethylene oxidation by methanotrophs and the use of a colorimetric assay to detect soluble methane monooxygenase activity

“…When M. trichosporiurn OB3b cells were incubated with naphthalene and the oxidation products were reacted with tetrazotized odianisidine, the resultant product(s) also absorbed maximally at 528 nm. It is known that phenols couple with diazonium salts to generate azo dyes (Saunders 1949, Parsons et al 1955. Synthetic 1-naphthol and 2-naphthol each reacted with the diazonium salt to produce compounds with absorption maxima at 528 nm and 527 nm, respectively.…”

Rapid Method for Detection and Quantitation of Hydroxylated Aromatic Intermediates Produced by Microorganisms

“…For example, 1-naphthol is the major product formed during the fungal oxidation of naphthalene (1,3,5). Spectrophotometric methods for the determination of 1-naphthol are rapid but lack the sensitivity required for the analysis of complex culture media (15)(16)(17). Methods that involve chromatographic separation of metabolites followed by spectrophotometric or radiometric detection procedures are sensitive but time-consuming.…”