Creatine & Creatinine

Method Description

This test quantifies creatine and its associated breakdown product, creatinine, in dietary supplements. Depending on the matrix, analytes are extracted using solution preparation or solid–liquid extraction (SLE) to release the target compounds. Analytical separation is performed using ultra-performance liquid chromatography (UPLC) with an ion-pairing (IP) mechanism, which enhances retention of the highly water-soluble, positively charged analytes on a reversed-phase column. Detection and quantitation are achieved using a diode array detector (DAD) with external calibration against certified reference materials. In addition to direct measurement, the method reports calculated analytes representing common creatine forms, including Creatine Monohydrate, Creatine HCl, Creatine Citrate, and Magnesium Creatine. The method provides accurate, reproducible results and is suitable for dietary supplement manufacturers, quality control laboratories, and contract testing facilities monitoring creatine content and related derivatives.