This lecture introduces the principles of instrumental analysis in the context of the living world, focusing on analytical chemistry techniques for separating sample constituents, identifying them, and determining their quantities. It covers qualitative and quantitative analysis, structural analysis, method selection, and various instrumental methods such as chromatography and spectroscopy. The lecture also discusses the importance of isolating and purifying samples before analysis, using techniques like distillation, crystallization, and chromatography. Additionally, it explores the application of spectroscopy in studying biological molecules and systems. Fundamental concepts like molecular orbitals, hybridization, the electromagnetic spectrum, and light absorption are also explained.