NMR spectroscopic analysis of 2-mercapto-5-methyl-1,3,4-thiadiazole in cefazolin.
A rapid, sensitive, and accurate method for the quantitative analysis of 2-mercapto-5-methyl-1,3,4-thiadiazole in cefazolin is presented. The method utilizes NMR spectroscopy and is based on the difference in the chemical shift of the methyl protons on free thiadiazole and the thiadiazole moiety of cefazolin.
NMR quantitative analysis of quinidine in mixtures of quinidine and hydroquinidine.
A new procedure for the rapid quantitative analysis of quinidine in mixtures of quinidine and hydroquinidine is described. The method is based upon measurement of the NMR spectrum of these compounds in deuterated chloroform, using 2,3,5-tri-bromothiophene as an internal standard. The signal chosen is from the vinyl group of quinidine. The great advantage of this procedure is that it permits the determination of the percentage of hydroquinidine in commercial bulk quinidine.
Über die quantitative Bestimmung von Barbituraten durch Kernresonanzspektroskopie
SummaryBarbiturates can be quantitatively determined in mixtures in presence of each other within the range of 0.1 to 1.5 mg by means of a NMR-spectrometric method employing a “time averaging computer”, if the characteristic signals do not overlap. The standard deviation amounts to approx. ± 10%.ZusammenfassungMit Hilfe eines „Time Averaging Computers“ können Barbiturate in Gemischen im Bereich von 0,1–1,5mg nebeneinander KMR-spektrometrisch quantitativ bestimmt werden, wenn die „Kennsignale“ sich nicht überlappen. Die Standardabweichung beträgt etwa ± 10%.