Short presentation on analytical chemistry.pptx

A brief presentation of the use of spectrometer and the preparation of standard and stock solutions

1. AN ORAL PRESENTATION ON STUDENT’S INDUSTRIAL WORK EXPERIENCE SCHEME UNDERTAKEN AT CENTRAL SCIENCE LABORATORY OAU, ILE-IFE, OSUN STATE. PRESENTED BY BALOGUN, Gbenga Peace CHM/2018/183 14 TH SEPTEMBER, 2023 1

2. CONTENTS Aims and Objectives of S.I.W.E.S Brief History About the Laboratory Aims and Objectives of S.I.W.E.S Introduction to UV-Visible Spectroscopy Instrumentation of UV-Visible Spectroscopy Applications of UV-Visible Spectroscopy Practical Approach to Spectrometric Analysis Conclusion 2

3. AIMS & OBJECTIVES OF S.I.W.E.S To provide an avenue for students to acquire industrial skills for experience during their course of study . To provide students with an opportunity to apply knowledge learnt in school to real work and practice, thereby bridging the gap between theory and practice. To prepare students for the work situation they might meet after graduation. 3

4. BRIEF HISTORY ABOUT THE LABORATORY Central Science Laboratory(CSL) was established in 1999 and equipped with state-of-the-art equipment that are used by students and academics to meet the cutting edge research needs of the university towards attaining the developmental objectives of our nation in the 21st century and beyond. At Central Science Laboratory, there is the availability of different facilities such as the UV-Vis Analysis, different equipment at the Chemistry and Biological Laboratory. 4

5. INTRODUCTION TO UV-VISIBLE SPECTROSCOPY Ultraviolet-visible (UV-vis) spectroscopy is used to obtain the absorbance spectra of a compound in solution or as a solid. The UV-vis region of energy for the electromagnetic spectrum covers a wavelength range of 800 - 200 nm . The Beer-Lambert Law is the principle behind absorbance spectroscopy. For a single wavelength, where b = path length of the cuvette (usually 1 cm), c = concentration of the solution (M).   5

6. INSTRUMENTATION OF UV-VISIBLE SPECTROSCOPY 6 Fig 1.1 Illustration of a double beam UV-Visible Spectrophotometer

7. APPLICATIONS OF UV-VISIBLE SPECTROSCOPY Qualitative analysis Quantitative analysis Detection of impurities Chemical kinetics 7

8. PRACTICAL ANALYSIS OF ASPIRIN SAMPLE OBJECTIVE To use the UV-Visible Spectrophotometer to determine the milligrams of acetylsalicylic acid (aspirin) in a commercial aspirin product . EQUIPMENTS UV-Vis Spectrophotometer with 2 cuvettes 250 mL volumetric flasks 1.0 mL graduated pipette 10 mL volumetric flasks or graduated cylinders Small beakers (50 mL) Balance and weighing paper 8

9. PROCEDURE FOR SAMPLE PREPARATION & ANALYSIS 9 Crushing & Weighing Digestion Standard Dilution Serial Dilution UV-Visible Analysis Fig 1.2 Schematic Representation of Sample Analysis Record & Calculate 2 APPROACHES: Prepare standard solutions of absorbing specie. Prepare the sample solution.

10. Solution Absorbance Concentration(g/L) A 0.740 0.080 B 0.610 0.064 C 0.452 0.048 D 0.290 0.032 E 0.151 0.016 Unknown 0.331 ? 10 ANALYSIS RESULTS & CALCULATIONS           Fig 1.3 Data collated from Aspirin Sample Analysis

11. 11 ANALYSIS RESULTS & CALCULATIONS Fig 1.4 Absorption Spectrum & Calibration Curve from Sample Analysis + c

12. Through the training, I was able to appreciate my chosen course of study even more, because I had the opportunity to blend the theoretical knowledge acquired from school with the practical hands on application of knowledge gained at the company to perform very important tasks that contributed in a way to my productivity in the company . My SIWES attachment at Central Science Laboratory was a privilege and I never regretted exploring it because of the massive practical knowledge I was able to tap into. 12 CONCLUSION

13. THANK YOU FOR LISTENING 13