Quantitative NMR assay for aspirin, phenacetin, and caffeine mixtures with 1,3,5-trioxane as internal standard

Eberhart, Suzanne Thomson; Hatzis, Alexander; Rothchild, Robert

doi:10.1016/0731-7085(86)80036-x

Cited by 18 publications

(6 citation statements)

References 9 publications

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“…The specificity and precision of the method have been assessed. HPLC (3-5), gaz kromatografisi (6-8), spektrofotometri (9)(10)(11)(12)(13)(14), susuz ortamda titrasyon (15), refraktometri (16), elektroforez (17), radyometri (18), NMR (19). Bu yöntemler önce ayırma sonra miktar tayini şeklindedir.…”

Section: Discussionunclassified

Aspirin ve Kafeinin Farmasötik Preparatlarda Birinci Türev UV Spektrofotometrisi ile Miktar Tayinleri

Onur¹,

Acar²

1989

Ankara Universitesi Eczacilik Fakultesi Dergisi

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ÖZET1. Türev UV spektrofotometrisi ile aspirin ve kafein in birarada bulunduklarında herhangi bir ayırma işlemi gerekmeksizin miktar tayinleri gerçekleştirilmiştir. Yöntem Türkiye ilaç piyasasında yer alan bir tablete uygulanmıştır. Yöntemin seçiciliği ve duyarlığı tayin edilmiştir. SUMMARYThe simultaneous determination of aspirin and caffeine in ad mixture was realized without any separation by first derivative UV spectrophotometry. Application of the method to a tablet marketing in Turkey was described. The specificity and precision of the method have been assessed. Anahtar Kelimeler: Aspirin, kafein, birinci türev spektrofotometri, ultraviyole spektrofotometri.

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Section: Discussionunclassified

Aspirin ve Kafeinin Farmasötik Preparatlarda Birinci Türev UV Spektrofotometrisi ile Miktar Tayinleri

Onur¹,

Acar²

1989

Ankara Universitesi Eczacilik Fakultesi Dergisi

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“…Te standard does not have to share its identity with any of the analytes of interest. Tis key feature makes quantitative NMR an extremely versatile technique, and numerous applications for the quantitative analysis of pharmaceutical compounds have been proposed over the decades [6,[11][12][13][14][15][16][17][18][19][20][21][22][23]. Te majority of the described experiments are 1D liquid state, but 2D and CPMAS experiments have also been proposed.…”

Section: Introductionmentioning

confidence: 99%

“…Whichever method is chosen, the quantifcation by NMR is always based on the comparison of the signal intensity of reference material with the signal intensity of the analyte(s), as the intensities are proportional to the molar concentrations and the number of protons contributing to the signal. Te reference signal can be provided by a reference material mixed with the analyte in one solution, internal referencing (IR) [18,25,29,30,32,[40][41][42][43][44], or by a separate solution, external reference (ER). Two methods for ER have been described; most commonly, two identical experiments are carried out, one time with the analyte and the other time with the reference material [6,45,46].…”

Section: Introductionmentioning

confidence: 99%

Quantitative NMR Interpretation without Reference

Santana

Almeida

França

et al. 2022

Journal of Analytical Methods in Chemistry

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As has been documented numerous times over the years, nuclear magnetic resonance (NMR) experiments are intrinsically quantitative. Still, quantitative NMR methods have not been widely adopted or largely introduced into pharmacopoeias. Here, we describe the quantitative interpretation of the 1D proton NMR experiment using only absolute signal intensities with the variation of common experimental parameters and their application.

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“…1 H NMR spectroscopy can be used to determine the relative amounts of components in mixtures by analyzing the relative integration values of proton signals of each compound, provided that the different compounds have sufficiently distinct NMR resonances and the absolute amount of one major (>1%) compound can be used as an internal standard. , Some early applications of qHNMR, including several in the field of chemical education, − utilized analysis of relative integration areas, and a classic experiment for undergraduate Instrumental Analysis involved the quantitative determination of a mixture of benzene and ethyl alcohol in CDCl 3 by 1 H NMR spectroscopy on the basis of relative integration areas . Some more recent qHNMR experiments for the teaching laboratory have utilized standard addition methods, , and qHNMR has been incorporated into kinetics and mechanistic studies. − However, the focus of the majority of these experiments has been on the relative concentrations of the components of mixtures, not the purity of an individual compound, which should be a topic of interest to undergraduate students.…”

Section: Introductionmentioning

confidence: 99%

qHNMR Analysis of Purity of Common Organic Solvents—An Undergraduate Quantitative Analysis Laboratory Experiment

et al. 2017

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NMR spectroscopy is currently a premier technique for structural elucidation of organic molecules. Quantitative NMR (qNMR) methodology has developed more slowly but is now widely accepted, especially in the areas of natural product and medicinal chemistry. However, many undergraduate students are not routinely exposed to this important concept. This article describes a simple and practical lab experiment that has been successfully performed by students in a Quantitative Analysis class for several years and is based on a comparison of relative integration areas of species present in spectra of compound mixtures. In this experiment, 1 H NMR spectroscopy is used to determine the purity of common organic solvents using dimethyl sulfoxide as an internal standard in D 2 O. Groups of students analyze unknown samples containing one of the following solvents: methanol, ethanol, 2-propanol, tetrahydrofuran, or acetone, to which water has been added as an impurity. Over a period of five years, 54 students analyzed samples ranging from 60% to 99% purity with an average error of 2.64%. This experiment fills a niche in the initial portion of a standard Quantitative Analysis lab sequence by differentiating between qualitative and quantitative analysis, providing exposure to equipment not usually encountered in an introductory analytical lab, and generating numerical data for students to analyze and evaluate.

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Quantitative NMR assay for aspirin, phenacetin, and caffeine mixtures with 1,3,5-trioxane as internal standard

Cited by 18 publications

References 9 publications

Aspirin ve Kafeinin Farmasötik Preparatlarda Birinci Türev UV Spektrofotometrisi ile Miktar Tayinleri

Aspirin ve Kafeinin Farmasötik Preparatlarda Birinci Türev UV Spektrofotometrisi ile Miktar Tayinleri

Quantitative NMR Interpretation without Reference

qHNMR Analysis of Purity of Common Organic Solvents—An Undergraduate Quantitative Analysis Laboratory Experiment

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