SUMMARY
This dissertation includes four main chapters:
Chapter one: The first chapter provides a concise review of the extraction process, micro-extraction techniques, including Cloud Point Extraction, and the drug under study, mesalazine. It also highlights the various analytical methods employed for the determination of mesalazine. The principle of the indophenol reaction, as well as CPE and Liquid-Liquid Micro-Extraction (LLME), are explained in detail.
Also, discuss surfactants, their chemical structures, and their various types. In addition to their chemical formulations, provides a detailed classification of surfactants as anionic, cationic, nonionic, and zwitterionic. The chapter concludes the stating the aim of the present work.
Chapter two: This chapter discusses the experimental part for the micro extraction procedure for the determination of Mesalazine. This includes the chemicals and instruments used throughout the work as well as a description of the general procedure for the preparation of the standard stock solutions.
Chapter three: This chapter involves two parts first of them using the oxidative coupling of mesalazine with dissolved oxygen in the presence of syringic acid under alkaline conditions. This results in the formation of a stable indophenol dye with a distinct blue color, which can be quantified at 615 nm. The method’s linear range spans from 1.25 to 50 µg mL-1, and it follows Beer’s law, with a molar absorptivity of 2220.53 mol-1 L cm-1. This approach demonstrates selectivity by accurately detecting MSZ even in the presence of interfering substances. The method is impressively sensitive, boasting a low limit of detection (LOD) of 0.093 µg mL-1 and a limit of quantitation (LOQ) of 0.282 µg mL-1.
Second part involves cloud point microextraction of above reaction. This dye can transition from blue to pink by forming an ion-pair complex with the acetate buffer (pH 3). To isolate the dye from the surrounding liquid, sodium sulfate (Na2SO4) and a nonionic surfactant, Triton X-114, are introduced, causing the dye molecules to form micelles around the surfactant at room temperature. Following this, NaOH is utilized to restore the blue color of the indophenol. The solution is then diluted, and its absorbance is measured at 635 nm using a visible spectrophotometer after optimizing experimental conditions. The resulting calibration curve demonstrates linearity within the range of 0.25 to 10 μg mL-1 of mesalazine, and the method achieves a limit of detection of 0.04 μg mL-1. This technique proves effective for accurately determining mesalazine content in drug formulations and serum, with an average recovery percentage of 99.2% and a preconcentration factor of around 20.
A procedure for the optimization of conditions for the determination of the studied drug by cloud point extraction. It explores the effects of various parameters on the process, such as the volume of NaOH and the concentration of syringic acid. And study impact of temperature and time on the rate of color formation of indophenol blue.
Chapter four: Chapter four presents an analysis of mesalazine in pharmaceutical formulations using a combined ion-pair assisted liquid phase microextraction IP-LPME and UV-Vis’s spectrophotometry method. It explores the effects of various parameters on the process, such as the volume of TBAHS (Tetrabutylammonium hydrogen sulfate) and NaOH, and the concentration of syringic acid (SA). The linear range for measuring red species in pharmaceutical formulations was established as 0.005-0.08 µg mL-1, and its limit of detection was determined to be 0.003 µg mL-1. The method demonstrated good precision, with relative standard deviation percentages (RSD) falling within the range of 4-6. With a preconcentration factor of 50 at 520 nm. The solvent extract was placed on the pedestal of the spectrophotometer using a commercially available 10 µL syringe.
Chapter five: The chapter includes dual detection of Fe (III) in blood serum by using Spectro-Cloud Point Extraction (Spectro-CPE) and Fluorometric-Cloud Point Extraction (Fluro-CPE).
combining cloud point extraction, spectrophotometry, and spectrofluorometry was developed for the precise and selective identification and quantification of iron. The method involves creating a complex between ferric iron Fe (III) and mesalazine reagent. This complex is then extracted into a Triton X-114-rich nonionic surfactant phase. Spectrophotometric analysis of the extracted complex is carried out at 550 nm. Additionally, the method employs spectrofluorometric determination, involving the reduction in fluorescence intensity of the mesalazine reagent. The excitation wavelength for this determination is 338 nm, and the emission wavelength is 496 nm. In terms of its performance, the technique offers a dynamic linear range of (1 to 23 µg mL-1) and achieves a detection limit of 0.0121 µg mL-1, along with an enrichment factor of 4.52 for colorimetry. For fluorometry, the method’s range spans from (0.1 to 1.4 µg mL-1), with an impressively low detection limit of 0.0053 µg mL-1. The study investigated the effect of the volume of T-x114, different solvents, volume of NaCl and the volume of mesalazine on Spectrophotometric – cloud point extraction and spectrofluorometric – cloud point extraction.