Analytical chemistry is a branch of chemistry that focuses on the development and application of methods for determining the composition of substances. It is concerned with identifying, quantifying, and separating the components of a sample and determining their chemical and physical properties. Analytical chemistry plays a critical role in various fields such as medicine, environmental science, forensics, and quality control. The methods used in analytical chemistry range from simple procedures such as visual inspection and pH measurement to more complex techniques such as spectroscopy, chromatography, and mass spectrometry. These methods allow for the detection and measurement of a wide range of substances, from trace amounts in complex mixtures to major components in pure substances.