Which analytical method is typically used to assess the purity of a substance?

High-performance liquid chromatography (HPLC) is a highly effective analytical method for assessing the purity of a substance due to its ability to separate components within a mixture based on their interactions with a stationary phase and a mobile phase. HPLC provides detailed information about the composition of a sample, including the detection of impurities present at very low concentrations, which is crucial in purity assessment. The technique is particularly valuable in pharmaceutical and biochemical applications, where the presence of impurities can be critical to safety and efficacy.

HPLC is favored for purity testing because it offers high resolution, sensitivity, and speed, allowing for accurate quantification of compound concentrations. This capability makes it ideal for situations where regulatory compliance regarding purity standards is necessary, ensuring that products meet the required specifications before they are brought to market. Furthermore, HPLC can be used for both qualitative and quantitative analysis, enhancing its versatility in various applications.