Ferrozine | An-Najah Staff

Spectrophotometric Determination of ‎Cysteine and N-acetylcysteine in ‎Pharmaceutical Preparations

Thu, 2014-03-27 12:29 — Maher An-Natsheh

Journal Title, Volume, Page:

Microchimica Acta, Volume 129, Issue 1-2, pp 91-95

Year of Publication:

1998

Link:

http://link.springer.com/article/10.1007%2FBF01246854

Authors:

Maher Abu Eid

Chemistry Department , An-Najah National University , Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

An accurate fast spectrophotometric method for the determination of cysteine andN-acetyl-cysteine is presented, based on the oxidation of these amino acids by ferric ions in the presence of ferrozine, whereby a violet-coloured complex is formed which absorbs at 562 nm. The method was satisfactory for the determination of cysteine andN-acetylcysteine in samples within the range 0.02–6.00 μgml−1. Effects of time, acidity, ferric ions, ferrozine, sodium perchlorate concentrations and the tolerance limit for other amino acids have been reported. The method was applied to the determination of cysteine in amino acids mixtures andN-acetylcysteine in pharmaceutical preparations.

Spectrophotometric Determination of Tiopronin in Pharmaceutical Preparations

Thu, 2013-02-28 13:53 — Nidal Zatar

Journal Title, Volume, Page:

An-Najah Univ. J. Res. (N. Sc.), 15 (2001) 145-157.

Year of Publication:

2001

Link:

http://scholar.najah.edu/publication/journal-article/spectrophotometric-determin...

Authors:

Nidal Zatar

Chemistry Department, Faculty of Science, An - Najah N. University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, West Bank, Palestine

[email protected]

Maher A. Abu-Eid

Tamara Kamal

Mohammad Hannoun

Preferred Abstract (Original):

Two spectrophotometric methods are described for spectrophotometric determination of tiopronin in pharmaceuticals. They are based on the oxidation-reduction reaction between tiopronin and iron(III)-ferrozine complex [system I] or iron(III)-di-2-pyridyl ketone-2-thiophenoyl-hydrazone complex [system II]. The produced colored iron(II)-Ferrozine or iron(II)-di-2-pyridyl ketone-2-thiophenoyl-hydrazone complex absorbs at 562 nm and 656 nm, respectively. The effect of different factors such as; pH, reagent concentration, times, temperature and the tolerance amount of the common excipients have been reported. Applying the optimum working conditions, tiopronin can be determined over the range 0.2-8.6 and 0.5-17.0 ppm when using system I and II, respectively. The two methods offer high selectivity, sensitivity and accuracy with RSD less than 1.5% for five measurements. The proposed methods were applied successfully for the determination of tiopronin in Captimer tablets.