naphthol isomers were simultaneously and spectrophotometrically determined in wastewater, using a model based on net analyte signal (nas). the calibration method used is a variation of the original hybrid linear analysis method as proposed by goicoechea and olivieri (hla/go). owing to spectral interferences, the simultaneous determination of mixtures of naphthol isomers, using a spectrophotomet...

Naphthol is a widely used chemical and medical detection biomarker, but it harmful to human health the environment. Therefore, highly sensitive method for naphthol urgently required. Herein, an electrochemical microsensor simultaneous of isomers was fabricated by in situ growth three-dimensional graphene network (3DGN) on screen-printed electrodes. The exhibited good sensing responses typical (...

Naphthol isomers were simultaneously and spectrophotometrically determined in wastewater, using a model based on net analyte signal (NAS). The calibration method used is a variation of the original hybrid linear analysis method as proposed by Goicoechea and Olivieri (HLA/GO). Owing to spectral interferences, the simultaneous determination of mixtures of naphthol isomers, using a spectrophotomet...

Urinary naphthol is an established human biomarker used for assessing both occupational and environmental exposure. However, 1-naphthol is a metabolite of the insecticide carbaryl while both the 1- and 2-isomers are metabolites of naphthalene. Thus, urinary 1-naphthol levels will reflect combined exposure to both substances, particularly at environmental levels. The interpretation of biomarkers...

Pseudomonas sp. strain PP4 and C5 utilize phthalate isomers (o-, mand p-) and carbaryl as carbon source, respectively. Degradative pathways were elucidated by isolating and characterizing metabolites, whole-cell O2 uptake and enzyme activity studies. Metabolic studies suggest that phthalate isomer degrading pathways converge at 3,4-dihydroxybenzoic acid. Phthalate dioxygenases responsible for t...

peptide synthesis. Enzymatic peptide synthesis is more advantageous than chemical synthesis since the enzymatic method is stereoselective and is secure from racemization. There are, however, several problems to be solved with this method. Secondary hydrolysis of the resulting peptide may arise from the inherent nature of the protease. Moreover, the method is limited to the use of amino acid der...

Conversion of 1and 2-tetralone was investigated over acid HY zeolite under various reaction conditions in the vapor phase. Reactions were conducted in a fixed-bed reactor at 300, 400 and 500 C in hydrogen atmospheric pressure. It was found that 1and 2-tetralone are thermally unstable and thermal reaction has a contribution, particularly at high temperatures. The reactivity of 2-tetralone was si...

The preparation and characterization of p-tert-butylcalix[4]arene-1,3-bis(allyloxyethoxy)ether (CA[4]-BAE) chemically coated capillaries via a free-radical reaction with vinyltriethoxysilane (VTES) that was attached onto the inner wall previously were carried out. IR spectra and decreased electroosmotic flow (EOF) suggested that the capillary was successfully coated with CA[4]-BAE. A slight slo...

The simultaneous determination of vitamin D2 and its isomers by high-speed liquid chromatography (HSLC) is described. Preferred operating conditions for the resolution and quantitation of vitamin D2 5,6-trans-vitamin D2, ergosterol, lumisterol2, isovitamin D2, isotachysterol2, tachysterol2, and previtamin D2 are as follows: column, "Zorbax" SIL (25 cm x 2.1 mm i.d.); pressure, 100-120 kg/cm2; t...