To develop a new more accurate spectrophotometric method for detecting monoamine oxidase inhibitors from plant extracts, a series of amine substrates were selected and their ability to be oxidized by monoamine oxidase was evaluated by the HPLC method and a new substrate was used to develop a peroxidase-linked spectrophotometric assay. 4-(Trifluoromethyl) benzylamine (11) was proved to be an exc...

a novel optical sensor has been proposed for sensitive determination of bismuth ion basedon immobilization of 4-(4-nitrophenylazo)-1-naphthol on a triacetylcellulose membrane.chemical binding of bismuth ions in solution with a 4-(4-nitrophenylazo)-1-naphtholimmobilized on the triacetylcelluse surface could be monitored spectrophotometrically. theoptode shows excellent response over wide concent...

A colorimetric method for detection and assay of mustard gas in urine after addition of thymolphthalein is reported. The detection limit was 80 ng/ml of llrine. Mustard gas could also be detected in urine after extraction with gas chromatography using FID detector. The detection limit was 10 ng/ml. In addition, thiodiglycol, a metabolite of mustard gas, could be converted to mustard with ...

Introduction The identification and quantification of hexavalent chromium in solid samples is an important factor in characterization studies. The speciation of elements is a developing feature of analytical methods; the evaluation of the environmental and biological impact of the Cr (VI) compounds on environmental matrices is fundamental because of their demonstrated toxicity and potential car...

A simple and fast Cloud Point Extraction (CPE) preconcentration of Acid Blue 29 (AB 29) dye was developed prior to its spectrophotometric determination. The suggested procedure successfully applied for the determination AB in different water samples with high recoveries. Optimization experimental conditions such as surfactant type volume, pH, stirring, centrifugation were studied. effect interf...

the multivariate calibration method, partial least square regression (pls) was applied for thesimultaneous spectrophotometric determination of lidocaine (lid) and hydrocortisone acetate(hca) in their mixtures. the parameters of chemometric technique were optimized and theproposed method was validated with synthetic samples and applied to analyze these drugs inpharmaceutical products with good a...

a simple, rapid and sensitive spectrophotometric method has been proposed for the determinationof vanadium (iv). the method is based on the catalytic effect of v (iv) on the oxidation of alkali blue bypotassium bromate at ph 4. the rate of decrease in the absorbance of alkali blue (at 572 nm) wasproportional to the concentration of v (iv) in the range of 100-6000 ng ml-1. the detection limit wa...

Quantitative tests for human immunodeficiency virus type 1 (HIV-1) RNA in plasma and proviral DNA in peripheral blood mononuclear cells (PBMC) provide valuable information on the status of HIV-1 infection. This paper describes tests that were carried out with commercially available materials and an enzyme-linked immunosorbent assay reader for detecting spectrophotometric changes. Samples consis...

The construction of an electrochemical immunosensor coupled to differential pulse voltammetry (DPV) for the detection of domoic acid (DA), a neurotoxic aminoacid responsible for the human syndrome known as "Amnesic Shellfish Poisoning" (ASP), is proposed here. The method involves the use of disposable screen-printed electrodes (SPEs) for the immunosensor development based on a "competitive indi...