طريقة كروماتوغرافيا السائل عالي الأداء لتقديرالاسبرين بعد تفاعل الاشتقاق ودراسة الحركية

High Performance Liquid Chromatography Method for Determination of Aspirin after Derivatization Reaction and Kinetic Study

Abstract
This study involves the quantification of Aspirin (Acetyl salicylic acid) using Reversed Phase High-Performance Liquid- Chromatography (RP-HPLC). A key element of this method was the synthesis and characterization of a novel Azo compound called (E)-2-acetoxy-5-((4-hydroxyphenyl) diazenyl) benzoic acid (AHPDBA). AHPDBA was synthesized through an Azo coupling reaction of Acetyl salicylic acid and a diazonium salt derived from 4-amino phenol. The resulting AHPDBA compound was subsequently characterized using UV-Visible spectroscopy, FT-IR spectroscopy, and gas chromatography-mass spectrometry (GC-MS).
Reversed-phase high-performance liquid chromatography (RP-HPLC) was employed for method optimization. The effects of mobile phase composition, pH, buffer, flow rate, injection volume, and temperature were carefully studied. Aspirin Calibration curve was created using concentrations ranging from (1 – 100 µg.mL-1). By using RP-HPLC the kinetic study of the alkaline and oxidative degradation process of AHPDBA, the order rate constants, half-lives, and activation energies were calculated. Method validation of the proposed method included the determination of Linearity coefficient, precision, accuracy, Limit of Detection (LOD), and Limit of Quantification (LOQ). The method exhibited good linearity with the (1-100 µg.mL-1) concentration ranges, with a correlation coefficient (r2) of 0.9999. Excellent precision and accuracy were demonstrated with Relative Standard Deviation (RSD %) values below 0.291 % and recoveries ranging from 99.871-100.532 %. The LOD was 0.930µg.mL-1, and the LOQ was 2.820µg.mL-1. This study demonstrated that the proposed method was applied successfully for quantification of Aspirin in a pharmaceutical preparation.