Kinetic Spectrophotometric Determination of N-acetyl-L-cysteine Based on the Reduction of Copper(II)-neocuproine Reagent

Radić, Njegomir; Kukoc-Modun, Lea; Biocic, Maja

doi:10.5562/cca2161

Cited by 8 publications

(8 citation statements)

References 22 publications

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“…[21] NACET reduces Cu(II)-neocuproine reagent to form an orange-yellow colored Cu(I)-neocuproine complex with an absorbance maximum at 458 nm which was used in the following experiments. The effect of the pH value of the reaction mixture was investigated over the range 2.0 -8.0 using Britton-Robinson buffer solution.…”

Section: Cu-neocuproine Methodsmentioning

confidence: 99%

“…The proposed buffer solution was used for the determination of NAC. [21,22] In the pH range from 3.0 to 8.0, there were no significant differences in the kinetics and the measured absorbance values Cu-BCA METHOD BCA has been used as an analytical reagent for the determination of proteins [24] and also as a chromogenic reagent for the determination of copper in serum and biological samples. [25] According to the literature, Cu(I)-BCA complex has maximum absorbance at 562 nm in the visible region and at 354 nm in the near UV region.…”

Section: Cu-neocuproine Methodsmentioning

confidence: 99%

“…[14] Cu(II)-neocuproine has also been used for the analysis of NAC of which the sulfhydryl group (SH) reduces Cu(II)-neocuproine to the chromogenic Cu(I)-neocuproine. [21,22] For the determination of NACET we tested reagents which have been previously used for its congener NAC. We studies a two-step approach which involves reduction of Fe(III) by NACET and subsequent complexation of Fe(II) with 1,10-phenantroline or 2,4,6-trypyridyl-s-triazine.…”

Section: Introductionmentioning

confidence: 99%

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Kinetic Spectrophotometric Determination of N-Acetyl-L-cysteine Ethyl Ester (NACET) Generating Chromogenic Copper(I)Ln Complexes with Different Ligands

Kukoc-Modun¹,

Tsikas²,

Kraljević³

et al. 2017

Croat. Chem. Acta

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Three simple, sensitive and robust kinetic spectrophotometric methods for the determination of a novel lipophilic thiol compound, N-acetyl-L-cysteine ethyl ester (NACET), have been developed and validated. The methods are based on the reduction of Cu(II)-ligand complex to Cu(I)-ligand complex with the analyte. Studied ligands were neocuproine, bicinchoninic acid (BCA) and bathocuproine disulfonic acid (BCS). The development of chromogenic complexes was followed using kinetic setup with spectrophotometric detection at 458, 562 and 483 nm for the reactions of NACET with neocuproine, BCA and BCS, respectively. The calculated reaction orders with respect to NACET concentration were found to be 1.07, 1.01, 1.07, respectively, thus confirming a first order of reaction. The initial rate and fixed time methods were utilized for constructing calibration curves. Assays limits of detection were 1.4 × 10 -7 , 3.2 × 10 −7 and 6.0 × 10 −8 mol L -1 , respectively. The analytical performance of the methods, in terms of accuracy and precision, was established.

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Section: Cu-neocuproine Methodsmentioning

confidence: 99%

Section: Cu-neocuproine Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Kinetic Spectrophotometric Determination of N-Acetyl-L-cysteine Ethyl Ester (NACET) Generating Chromogenic Copper(I)Ln Complexes with Different Ligands

Kukoc-Modun¹,

Tsikas²,

Kraljević³

et al. 2017

Croat. Chem. Acta

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“…Many spectrophotometric methods were used for ACT estimation in bulk form and in pharmaceuticals; some of these methods were based on redox reactions due to the reducing effect that ACT exhibits, of these we can mention the oxidation of ACT with Fe 3+ followed by reaction of the produced Fe 2+ with 2,4,6-tripyridyl-s-triazine (TPTZ) [16]. Another method relies on the reduction of Cu (II) neocuproine to Cu (I) neocuproine in Britton-Robinson buffer [17]. Other published methods depend on derivatization of ACT with various reagents such as 4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) [18], 2,4-dinitrofluorobenzene (DNFB) [19] and a new reagent called ethylpropiolate (EPL) which was used for on-line derivatization of ACT, where the formed derivative was detected by using sequential injection analysis [20].…”

Section: Introductionmentioning

confidence: 99%

Spectrofluorimetric Estimation of Some Sulfhydryl–Containing Drugs by Demasking Reaction of the Palladium Chelate of 8-Hydroxyquinoline-5-Sulfonic Acid

Rs¹,

Sf²,

Hewala³

et al. 2017

Pharm Anal Acta

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A simple and sensitive spectrofluorimetric method has been developed for the determination of some selected sulfhydryl-containing drugs namely Acetylcysteine (ACS), Captopril (CAP) and Mesna (MSN).The method is based on the interaction of the drugs with potassium (5-sulfoxino) palladium II in alkaline medium in presence of magnesium ions, where the sulfhydryl group combines with palladium from the non-fluorescent potassium bis (5-sulfoxino) palladium II. The resulting 8-hydroxy-5-quinoline sulfonic acid coordinates with magnesium to form the fluorescent chelate that is a measure of the amount of sulfhydrl containing drug analyzed. The fluorescence intensity was measured at an emission wavelength of 485 nm, by excitation at 345 nm. All the experimental parameters affecting the reaction were studied and optimized. The proposed method was applicable over the concentration range of 0.04-0.44 µg/mL for the three drugs and was applied for their determination in bulk form and in pharmaceutical preparations without interference from common excipients. The assay results were statistically compared with those obtained from previously reported methods where no significant difference was found between them. The selectivity and the stability-indicating aspect of the proposed method were confirmed by preparing the disulphides of the studied drugs and applying the reaction to the parent drugs in presence of their disulphides where no interference was detected from these related substances. By virtue of its high sensitivity, the proposed method was also extended to analyze the drugs in spiked human plasma and urine.

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“…The developed methods include fluorimetry 6 , high performance liquid chromatography (HPLC) 7,8 , potentiometry 9 and spectrophotometry 10,11 . In the literature, a kinetic based method is available that include the application of buffers 12 which makes the quantitation process a bit lengthy, in the methods involving buffers numerous pH points are selected (2.0 -8.0) to prepare the Britton-Robinson buffer, further the trial and selection of the proper buffers solution is itself an addition and tedious process. The method involves other two reagents in addition to the buffer which means lot of trails and investigations are performed to optimize the proper reaction condition as in the article authors investigated molar ratio of Cu II and neocuproine in the reaction mixture.…”

Section: Introductionmentioning

confidence: 99%

Iodate Oxidation of N-Acetyl L-Cysteine: Application in Drug Determination and Characterization of Its Oxidation and Degradation Product by Mass Spectrometry

Siddiqui

Wabaidur

ALOthman

et al. 2014

J. Chil. Chem. Soc.

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A kinetic spectrophotometric method based on the initial rate measurement has been developed for the determination of N-acetyl L-cysteine. The developed method is based on the oxidation of N-acetyl L-cysteine with iodate. The reaction product was studied and characterized using the mass spectrometry and the structure of the product was proposed. From the mass spectrometric studies it was concluded that the oxidation of the drug resulted in the formation of a disulfide. The developed method was validated as per the guidelines of international conference on harmonization. The developed initial rate method was found to be linear in the concentration range of 1.25 -30 µg ml -1 . The detection and quantitation limits were found to be 0.018 and 0.056 µg ml -1 . In the current study, the degradation product of N-acetyl L cysteine was also prepared and identified using mass spectrometry.

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Kinetic Spectrophotometric Determination of N-acetyl-L-cysteine Based on the Reduction of Copper(II)-neocuproine Reagent

Cited by 8 publications

References 22 publications

Kinetic Spectrophotometric Determination of N-Acetyl-L-cysteine Ethyl Ester (NACET) Generating Chromogenic Copper(I)Ln Complexes with Different Ligands

Kinetic Spectrophotometric Determination of N-Acetyl-L-cysteine Ethyl Ester (NACET) Generating Chromogenic Copper(I)Ln Complexes with Different Ligands

Spectrofluorimetric Estimation of Some Sulfhydryl–Containing Drugs by Demasking Reaction of the Palladium Chelate of 8-Hydroxyquinoline-5-Sulfonic Acid

Iodate Oxidation of N-Acetyl L-Cysteine: Application in Drug Determination and Characterization of Its Oxidation and Degradation Product by Mass Spectrometry

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