caffeine analysis of excedrin and excedrin pm

1. Robin Roland Caffeine Analysis of Excedrin and Excedrin PM

3. Methods Two techniques were used: Thin Layer Chromatography and Gas Chromatogram Mass Spectrometry. Thin Layer Chromatography, or TLC, is a qualitative test that confirms the presence or absence of a compound. GCMS is a quantitative technique that can tell you what compounds are present in a substance, and the relative amounts of these substances.

4. Background Information Excedrin and Excedrin PM are both analgesics. Analgesics are defined as substances that relieve pain. The most common one is aspirin, and acetaminophen is the analgesic found in Excedrin brands. Caffeine is often added to painkillers to counteract the sedative effects of the analgesic, and the PM medications are assumed to have no caffeine. Binding materials such as starch, microcrystalline cellulose, or silica gel are often added.

5. Procedure First, 1% solutions of Excedrin, Excedrin PM, and pure caffeine were made. The solutions were made with ethanol. The two Excedrin solutions were filtered with a Buchner funnel to remove any of the insoluble binder. Pure ethyl acetate was used as a solvent for the chromatogram, and the plate was examined under UV light to see the spots.

6. The next portion of the experiment involved the GCMS. 10 microliters of the Excedrin and Excedrin PM solutions were placed in the chromatogram for evaluation.

7. Results Both the TLC and the GCMS indicated that there was no caffeine present in the Excedrin PM. There was caffeine added to the Excedrin. The relative amounts of the compounds in analgesics were determined by integration of the area under the curve of the GCMS results. The GCMS results showed that there was three times as much caffeine in the ExcedrinPM as in the regular Excedrin. There is approximately 3.6 times as much acetaminophen as caffeine in the regular Excedrin.