Trichloroacetic acid (TCA) is widely used in analytical chemistry as a standard sample for calibration and quality control in various testing procedures. It serves as a reference material in environmental analysis to detect chlorinated compounds in water and soil samples. TCA is also employed in biochemistry for protein precipitation, enabling the separation of proteins from nucleic acids and other cellular components during sample preparation. In clinical laboratories, it is used to deproteinize blood and urine samples prior to metabolite analysis. Additionally, TCA acts as a derivatizing agent in chromatographic techniques, improving the detectability of certain analytes. Its role as a standard ensures accuracy and reproducibility in quantitative assays across pharmaceutical, environmental, and biomedical research fields.