الفهرس 
PART I General IntroductionOnly 14 pages are availabe for public view
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Abstract
The present work deals with presenting two novel methods (i) for testing peak purity during HPLC separation, (ii) assessing peak symmetry. The methods depend upon calculating coefficient of orthogonal functions over specified segments of the eluted peaks to reveal the presence of co-eluting impurities. The thesis comprises four parts: Part I: This part describes a general introduction about peak purity assessment techniques and the importance of purity verification for chromatographic separation analysis. The introduction discusses each technique including the orthogonal function method. It also illustrates the proposed method that is based on the application of the orthogonal function ratios to the eluted peaks for testing peak purity. Part II: This part describes the application of the proposed method developed on paracetamol chromatographic peak as a model standard curve. Different percentage contaminations of paracetamol peak (varying from 100 % to 5 %) have been introduced to the standard curves as early and late coelution. Other general contamination is also considered. The combined paracetamol contaminations curves have been compared to the standard curves of paracetamol. The method used depends on calculating coefficients of orthogonal functions over specified selected segments (6 and 12 points orthogonal polynomials) for the standard curve and the contaminated curves of paracetamol. Ratios (|Q2|/ Q 0) of the pure and contaminated paracetamol curves were calculated where the deviation of the ratio indicating the presence of impurity. The study reveals that the results obtained were constant and reproducible when applied on different concentrations of paracetamol. The proposed method used has succeeded to efficiently assess peak purity. Part III: This part includes an introduction to peak asymmetry (Tailing factor) and USP method used for its calculation. The part presents the application of a novel method to assess peak symmetry during HPLC analysis using orthogonal function. The new method (Ghada Asymmetry Factor ”GAF”) was applied on pure and contaminated paracetamol. BASIC program is used for calculation of the orthogonal function coefficient. GAF proved to be simpler method than USP formulae for determination of chromatographic peak symmetry.GAF could be used to study the effect of peak purity on peak asymmetry.