Hi, In this task for our school, we were requested to investigate a method for testing the amount of caffeine content in coffee.
There are 3 main questions as fellows
1. What would be a good method to measure the amount of caffeine in coffee without extracting it?
2.What is the chemical reaction equation for caffeine oxidaton? When caffeine is exposed to oxygen, does it have a large effect or just....
3.What happenes if heat is added to caffeine, would the amount of caffeine in coffee decrease or increase?
1. Good depends on what you think "Good" means. Most preforming labs would choose CAPILLARY ELECTROPHORESIS
2. I am uncertain of your question. Caffeine causes bronchial dilation in the lungs, which reduces oxygen intake.
3. 22 mg·mL−1 (25 °C)
180 mg·mL−1 (80 °C)
670 mg·mL−1 (100 °C)
So as temp goes up, more caffeine is soluble in the coffee.
Sure, I can help you with your questions.
1. To measure the amount of caffeine in coffee without extracting it, you can use a method called spectrophotometry. Spectrophotometry measures the absorption of light by a solution to determine the concentration of a particular substance. In this case, you can prepare a coffee sample and use a spectrophotometer to measure the absorption of light at a specific wavelength that is known to correspond to caffeine. By comparing the absorption value to a calibration curve, you can determine the concentration of caffeine in the coffee.
2. The chemical reaction equation for caffeine oxidation is as follows:
Caffeine + Oxygen → 3-methyluric acid + Theobromine + Carbon dioxide + Water
When caffeine is exposed to oxygen, it undergoes oxidative degradation, resulting in the production of various byproducts such as 3-methyluric acid, theobromine, carbon dioxide, and water. This process is commonly known as oxidation. The extent of the reaction depends on several factors, including the presence of catalysts, temperature, and duration of exposure to oxygen.
3. When heat is added to caffeine, the amount of caffeine in coffee does not increase or decrease. Caffeine is a stable compound and does not break down or react significantly when exposed to heat. However, it is important to note that coffee itself can be affected by heat. Excessive heat or prolonged exposure to high temperatures can lead to the degradation of other components in coffee, which may impact the taste, aroma, and overall quality of the beverage.