[Determination of caffeine using high-performance liquid chromatography].

The present paper reports a method of caffeine assay in human saliva using high-performance liquid chromatography (HPLC). Samples of saliva were extracted into a mixture of chloroformisopropanol, the extract was evaporated at 40 degrees C and reconstituted with 100 microliters of methanol. The internal standard was 8-chlorotheophylline, the mobile phase… CONTINUE READING