JOHOR BAHRU, Apr 24 – The Department of Physics at the Faculty of Science, Universiti Teknologi Malaysia (UTM), in collaboration with the Advanced Optical Materials Research Group (AOMRG), the Frontier Materials Research Alliance (FMRA), and the Malaysian Solid State Science and Technology Society (MASS), successfully organized an international webinar titled “Colour and Chemistry: Understanding UV-Vis Absorption Spectroscopy.” This lecture was part of the course SSCP 4473 – Spectroscopy and Material Analysis, featuring guest speaker Prof. Dr. Sunita Sharma, a Professor and Associate Dean from Galgotias University in India.
The webinar was held virtually from 2:00 PM to 4:00 PM (MYT) and was attended by undergraduate and postgraduate students, lecturers, and researchers. The aim of the session was to provide comprehensive insights into UV-Visible absorption spectroscopy, a crucial analytical technique employed across various fields, including chemistry, pharmaceuticals, environmental science, and materials research.
Prof. Dr. Sharma began the session by introducing the principles of spectroscopy and the interaction of electromagnetic radiation with matter. Participants were guided through important concepts such as electronic transitions (σ → σ*, π → π*, n → σ*, and n → π*), which occur when molecules absorb UV or visible light. Understanding these transitions is key to comprehending how compounds exhibit color and absorb specific wavelengths.
In the session, she discussed Beer-Lambert’s Law, expressed as A = εbc, which is fundamental for quantitative analysis in UV-Vis spectroscopy. Participants learned how this relationship is utilized to determine the concentration of compounds based on their absorbance. Professor Sharma then introduced the components of a UV-Vis spectrophotometer, explaining key parts such as radiation sources (e.g., deuterium and tungsten lamps), wavelength selectors, cuvettes, detectors, and signal processors.
To enhance participants’ understanding, the session included two engaging case studies. The first case study demonstrated the application of UV-Vis spectroscopy in Coca-Cola production, focusing on how it quantifies caffeine and caramel coloring to ensure consistent product quality. The second case study focused on environmental water analysis, demonstrating how UV-Vis spectroscopy can detect and quantify pollutants such as nitrates and aromatic compounds in river samples, highlighting its value for real-time, non-destructive environmental monitoring.
The webinar concluded with an interactive quiz and a Q&A session. Participants engaged in discussions on topics such as absorption shifts (bathochromic and hypsochromic), molar absorptivity, the effects of auxochromes, and the application of UV-Vis data in determining band gap energy. Professor Sharma’s clear explanations and practical examples effectively bridged the gap between theory and application, making complex subjects more accessible and relevant.
The Department of Physics would like to express its heartfelt appreciation to Prof. Dr. Sunita Sharma for her time, expertise, and engaging presentation. We also extend our gratitude to all participants and co-organizers—AOMRG, FMRA, and MASS—for contributing to the success of the event. This webinar showcases UTM’s ongoing commitment to academic excellence and global collaboration in advancing science and education.
By: Dr. Nurhafizah Hasim (AOMRG Leader) and Dr. Nur Hidayah Ahmad, Department of Physics, Faculty of Science, UTM.