Ultraviolet and light absorption spectrometry

Howell, James A. S.; Hargis, L. G.

doi:10.1021/ac00296a011

Cited by 13 publications

(1 citation statement)

References 127 publications

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“…The earliest applications were primarily in the area of near infra-red (NIR) spectroscopy [4,5], but over the past few years other types of probes have become readily available. Electronic absorption spectroscopy (EAS) [6] is particularly useful where all or most compounds have chromophores, which is typical of pharmaceuticals, as many active compounds contain aromatic rings that have characteristic absorbances. On-line acquisition of data is now quite straightforward, meaning that EAS can be acquired at regular intervals (typically between 20 s and 5 min) over the course of a reaction.…”

Section: Introductionmentioning

confidence: 99%

Monitoring of a second‐order reaction by electronic absorption spectroscopy using combined chemometric and kinetic models

Thurston

Brereton

Foord

et al. 2003

Journal of Chemometrics

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This paper reports the application of 11 methods for obtaining kinetic constants from a second-order reaction, that between phenylhydrazine and benzophenone. In this type of reaction the number of absorbing species is lower than the number of steps in the reaction minus one, resulting in a rankdeficient response matrix. The methods used include traditional univariate curve fitting, classical least squares using previously recorded pure spectra, alternating least squares methods with both kinetic and non-negativity constraints, and target-testing methods using principal component scores. An additional recently proposed method based on difference spectra is also examined, suitable for any single-step closed reaction. The methods that performed best were difference spectra, kinetically constrained alternating least squares, and target-testing approaches. Limitations of the traditional methods are described.

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Section: Introductionmentioning

confidence: 99%