Measurement of Caffeine Metabolites in Urine Using Diode-Array Detection HPLC

Publisher Website
Google Scholar
Abstract
Diode-array detection high performance liquid chromatography (HPLC) offers significant advantages when compared to conventional UV HPLC detection. These advantages include important spectral information such as the τ max and the UV spectra of each eluting peak. The spectral scans are obtained at the peak start, peak apex and peak end. This provides a comparison of these spectra so that peak homogeneity can be calculated. Standard spectra can be stored and compared to eluting peaks for “purity”. Therefore, peak identification is based not only on retention time but the aforementioned spectral information. Recently, pathways involved in the metabolism of caffeine have been determined. One of the pathways involves the N-acetyltransferase system. Thus, a safe non-invasive and convenient procedure is now available to determine the N-acetylation phenotype. This is important because a number of toxicities have been associated with acetylator phenotype. The present paper indicates the utility of the diode-array detector for performing these studies. Use of this detector provides greater accuracy and reliability in correctly identifying the key metabolites required for classification as compared to conventional detection HPLC.