Determination of methylxanthines in urine by liquid chromatography with diode array UV detection.

@article{Zambonin2004DeterminationOM,
  title={Determination of methylxanthines in urine by liquid chromatography with diode array UV detection.},
  author={Carlo Giorgio Zambonin and Antonella Aresta and Francesco Palmisano},
  journal={Journal of pharmaceutical and biomedical analysis},
  year={2004},
  volume={36 3},
  pages={621-4}
}
A liquid chromatography-diode array UV detection (LC-UVDAD) method for the simultaneous determination of four methylxanthines (caffeine, theobromine, paraxanthine and theophylline) is described. The chromatographic separation was achieved on a LC-18-DB column using 20:80 methanol:buffer (5mM citric acid adjusted to pH 5 with triethylamine) as mobile phase. The method has been applied to urine samples. The overall procedure had % recoveries ranging from 81.6 +/- 2.6 (theophylline) to 99.3 +/- 6… CONTINUE READING