Showing 1-27 of 27 results for "70382"
Linxiao Gao et al.
Analytica chimica acta, 626(2), 174-179 (2008-09-16)
A novel and simple spectrophotometric method for the determination of Captopril with sodium 1,2-naphthoquinone-4-sulfonate is established in this paper. The detailed reaction mechanism is proposed and discussed. It is based on the fact that captopril can catalyze the reaction between...
Ayman A Gouda et al.
Drug testing and analysis, 4(12), 991-1000 (2011-05-04)
Two new simple, sensitive, accurate, and precise spectrophotometric methods have been developed and validated for the determination of cefdinir (CFD) in bulk drug and in its pharmaceutical formulations. The first method was based on the reaction of CFD with 1...
P Nagaraja et al.
Journal of pharmaceutical and biomedical analysis, 17(3), 501-506 (1998-07-10)
A rapid, sensitive and simple spectrophotometric method is proposed for the determination of hydrolysis products of paracetamol (PRL) and phenacetin (PHN) with sodium 1,2-naphthoquinone-4-sulphonate and cetyltrimethyl ammonium bromide (CTA) in alkaline medium. The absorbances are measured at 570 and 500...
Masoumeh Hasani et al.
Analytical biochemistry, 365(1), 74-81 (2007-03-22)
A spectrophotometric method for simultaneous analysis of glycine and lysine is proposed by application of neural networks on the spectral kinetic data. The method is based on the reaction of glycine and lysine with 1,2-naphthoquinone-4-sulfonate (NQS) in slightly basic medium....
Li Xiao Xu et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 59(13), 3103-3110 (2003-10-30)
Spectrophotometric determination of procaine hydrochloride is described. The procaine hydrochloride reacts with 1,2-naphthoquinone-4-sulfonic acid in pH 3.60 buffer solution to form a salmon pink compound, and its maximum absorption wavelength is at 484 nm, epsilon(484)=5.22 x 10(3).The absorbance for procaine...
Natividad García-Villar et al.
Journal of chromatography. A, 1216(36), 6387-6393 (2009-08-01)
A new HPLC method for determining biogenic amines in wines is developed. This method is based on pre-column amine derivatization, further separation of derivatives and on-line hyphenation of HPLC to atmospheric pressure chemical ionization mass spectrometry (APCI-MS). Biogenic amines have...
Y. Asahi et al.
Chemical & Pharmaceutical Bulletin, 32, 3093-3093 (1984)
D Hernando et al.
Journal of chromatography. A, 859(2), 227-233 (1999-11-26)
A liquid chromatographic method for the determination of aniline in cyclamate sweeteners based on a pre-column derivatization with 1,2-naphthoquinone-4-sulfonate (NQS) is proposed. Aniline traces were extracted from the cyclamate samples using dichloromethane. After solvent evaporation, the dry residue was derivatized...
C. Molins Legua et al.
Fresenius Journal of Analytical Chemistry, 349, 311-311 (1994)
R M Latorre et al.
Journal of chromatography. A, 934(1-2), 105-112 (2002-01-05)
This paper examines the potentiality of in-capillary derivatization for improving the sensitivity of the spectrophotometric detection of amino acids in capillary zone electrophoresis. 1,2-Naphthoquinone-4-sulfonate was selected as the labeling agent of amino acids. The underivatized sample and the reagent solution...
R M Latorre et al.
Electrophoresis, 21(3), 563-572 (2000-03-22)
The application of chemometric techniques to the resolution of overlapped peaks in capillary electrophoresis (CE) is described. When a physical separation can not be completely accomplished, chemometrics might still resolve the determination of the analytes mathematically. CE with diode array...
Y Moliner-Martínez et al.
Journal of chromatography. A, 1059(1-2), 17-24 (2005-01-05)
A new method for dimethylamine determination in air is reported. The proposed assay is based on the employment of C18-packed solid phase extraction cartridges for sampling. The retained amine is then derivatized inside the cartridges with the reagent 1,2-naphthoquinone-4-sulfonate. By...
Ibrahim A Darwish et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 72(4), 897-902 (2009-01-13)
Spectrophotometric study was carried out, for the first time, to investigate the reaction between the antidepressant fluvoxamine (FXM) and 1,2-naphthoquinone-4-sulphonate (NQS) reagent. In alkaline medium (pH 9), an orange-colored product exhibiting maximum absorption peak (lambda(max)) at 470nm was produced. The...
L A Levchenko et al.
Membrane & cell biology, 11(1), 131-135 (1997-01-01)
Methods of biochemical and physicochemical analysis were applied for studying the role of Micrococcus luteus cell structure in gold accumulation. It was shown that membrane proteins were the main factors in this process. Moreover, different quinones played the main role...
The effect of impermeable oxidants on the growth of neoplastic cells.
D R Richardson et al.
In vitro cellular & developmental biology. Animal, 34(1), 30-34 (1998-05-30)
Linjin Ma et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 79(3), 599-602 (2011-05-03)
Boron determination by a charge transfer spectrophotometric method is described. Accompanied the reaction, a charge transfer complex can be formed by lysine with sodium 1, 2-naphthoquinone-4-sulfonate and boron in alkaline solution (pH 12.00). Subsequently, a new reaction mechanism has been...
L G Martinez et al.
Journal of chromatography. B, Biomedical sciences and applications, 718(1), 143-151 (1998-12-01)
Cefotaxime was derivatised with 1,2-naphthoquinone-4-sulphonate (NQS), extracted into solid-phase cartridges (C18) and detected using a UV-visible detection system. Optimum conditions for this new procedure were: hydrogencarbonate-carbonate buffer, pH 10.5, 5-min reaction time at 25 degrees C and an NQS concentration...
Natividad García-Villar et al.
Electrophoresis, 27(2), 474-483 (2005-12-07)
A sensitive CE method for determining biogenic amines in wines based on in-capillary derivatization with 1,2-naphthoquinone-4-sulfonate is presented. In this method, reagent and buffer solutions are introduced hydrodynamically into the capillary whereas the sample is injected electrokinetically, thus, allowing a...
Huai You Wang et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 60(12), 2933-2939 (2004-09-08)
Spectrophotometric determination of dapsone is described. The dapsone reacts with sodium 1,2-naphthoquinone-4-sulfonic in pH 6.98 buffer solution to form a salmon pink compound, and its maximum absorption wavelength is at 525 nm, epsilon525=3.68 x 10(4) l mol(-1) cm(-1). The absorbance...
Santiago Hernández-Cassou et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 879(17-18), 1270-1281 (2010-12-28)
This paper revises the derivatization approaches for the determination of biogenic amines in wines. Since most of these amines display poor spectroscopic features to be detected by UV absorption or emission (fluorescence) spectroscopy, derivatization is necessary to attain the desired...
Quanmin Li et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 67(2), 360-367 (2006-09-09)
A rapid, simple and sensitive method for the determination of lysine (Lys) using sodium 1,2-naphthoquinone-4-sulfonate (NQS) and tetradecyl benzyl dimethyl ammonium chloride (Zeph) is presented in this paper. The method is based on the russety product formed from Lys, NQS...
Leah Hlabangana et al.
Journal of chromatography. A, 1130(1), 130-136 (2006-07-04)
A liquid chromatographic method with post-column derivatization for the determination of biogenic amines in wines is proposed. The method is based on the separation of amines by ion-pair chromatography using sodium heptanesulfonate (SHS) and on-line labeling of analytes with 1,2-naphthoquinone-4-sulfonate....
Quanmin Li et al.
Analytica chimica acta, 583(1), 147-152 (2007-03-28)
A new method has been established for the determination of dopamine hydrochloride (DPH) using sodium 1,2-naphthoquinone-4-sulfonate (NQS) and tetradecyl benzyl dimethyl ammonium chloride (Zeph). This method is based on the formation of a pink compound from the reaction of DPH...
J A Kiernan et al.
Biotechnic & histochemistry : official publication of the Biological Stain Commission, 73(5), 244-254 (1998-11-26)
Anionic dyes, notably acid fuchsine, strongly stain the nuclei and cytoplasm of neurons severely damaged by injury or disease. We provide detailed instructions for staining nervous tissue with toluidine blue and acid fuchsine for optimal demonstration of injured neurons. Degeneration...
Quan-Min Li et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 66(3), 656-661 (2006-11-18)
A new method has been established for the determination of aminomethylbenzoic acid using sodium 1,2-naphthoquinone-4-sulfonate as the chemical derivative chromogenic reagent. This method is based on the formation of a pink compound from the reaction of aminomethylbenzoic acid and sodium...
Lixiao Xu et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 60(13), 3007-3012 (2004-10-13)
Spectrophotometric determination of ampicillin sodium is described. The ampicillin sodium reacts with sodium 1,2-naphthoquinone-4-sulfonic in pH 9.00 buffer solution to form a salmon pink compound, and its maximum absorption wavelength is at 463 nm, epsilon463 = 1.14 x 10(4). The...
Sameer A M Abdulrahman et al.
Drug testing and analysis, 3(10), 748-754 (2011-02-22)
A simple, sensitive, and selective spectrophotometric method has been developed for the determination of gabapentin (GBP) in capsules. The method is based on the reaction of GBP and sodium 1,2-naphthoquinone-4-sulfonate (NQS) in the presence of Clark and Lubs buffer of...

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