ABSTRACT
This chapter describes use of solid-surface room temperature phosphorimetry as a detection technique in the liquid chromatographic analysis of caffeine, theophylline, and theobromine. The analysis of the methylxanthines is important in the areas of nutrition and clinical chemistry. In the determination of methylxanthines by Ultraviolet (UV) spectroscopy in foods, it is necessary to separate out the large number of substances that potentially interfere. Chromatographic techniques are the most conveniently used for the final separation of methylxanthines, so that they can be determined by UV, without interference. Thin-Layer Chromatography offers an ability to analyze a large number of samples with reasonably good separation of the methylxanthines at a relatively low cost. Analytical studies in clinical chemistry relating to the determination of methylxanthines are concentrated in two areas. The first of these involves the analysis of various ethical pharmaceuticals. The second area involves the analysis of various body fluids for methylxanthines and their metabolites.
