Analytic method development is one of the key steps in the development of any chemical substance, including pharmaceuticals and small molecules. Analytic method development is to confirm the methods and conditions required for sample analysis according to project requirements, then to verify or analyze the quality and performance of the target sample. Analytic method development has different requirements in different industries. High performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometers (LC-MS) are two important means to control product quality. Both of them have the characteristics of accurate and reliable results, high sensitivity and resolution, strong specificity, simultaneous separation of substances, and so on. They can be used for the determination and separation of compound content as well as detection and identification of related substances.