ISSN:
1436-5073
Keywords:
caffeine
;
FTIR
;
DRIFT
;
transmission measurements
;
acetylsalicylic acid
;
paracetamol
;
propyphenazone
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Fourier transform infrared spectroscopy has been used for the quantitative determination of caffeine in several pharmaceutical products: acetyl salicylic acid, paracetamol and propyphenazone. The method is simple, rapid and selective, and allows the determination of caffeine without sample pretreatment and without separation from the matrix. Two techniques for measuring the infrared spectra of caffeine are described: transmission through pellets and diffuse reflectance from powder (DRIFT). In both methods, samples were diluted (1%) with KBr. Caffeine in pharmaceutical matrices was recovered within 5% error in pellets and 10% by DRIFT. Relative standard deviations were generally ⩽1.5% for repeated measurements on a single pellet and ⩽ 5% for measurements on different pellets. DRIFT in the vacuum mode gave rather large RSDs. The limit of detection of the pellet technique was about 0.5% caffeine in the original sample.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01243325
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