کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1237021 | 1495291 | 2005 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Study on the stability of noradrenaline and on the determination of its acidity constants Study on the stability of noradrenaline and on the determination of its acidity constants](/preview/png/1237021.png)
Noradrenaline is a catecholamine which has been largely recognised to play a very important role in biological systems. In view of the neurotransmitter's alleged importance, this work aimed at showing the influence of time on its spectral behaviour using different analytical methods and determining its acidity constants through spectrophotometric titration and by the so-called point-by-point analysis, where the samples are freshly prepared for each pH value investigated at the instant required. Because the catecholamines are light-sensitive and likely to react with the oxygen in the surrounding air, both methods used preclude its incidence onto the samples being analysed under the presence of a nitrogen atmosphere maintained over the solutions. The constants obtained through point-by-point analysis were log β1 = 30.71 ± 0.16, log β2 = 22.00 ± 0.15 and log β3 = 11.69 ± 0.16.
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 61, Issues 13–14, October 2005, Pages 3139–3144