Extraction and Purification of Caffeine from Tea Leaves
Pre-lab for Caffiene
1. Introduction
2. Prepare a flow chart of procedures AND show the location of the caffeine throughout each step of the experiment in the flow chart. (Hint: See the end of Expt 8 in Landgrebe). Make sure you also REFERENCE the procedures.
NOTE: Make sure that you look for organization of ideas and not just a copy of the procedure in boxes.
3. Questions 1,7,8,11 in Landgrebe (see page 140-141)
(MUST SHOW ALL WORK FOR FULL CREDIT). Note: Kp is equivalent to a (see lecture guide for definition).
Post-lab Report . This is an individual report
(i) Record all observations.
(ii) Use equations to help explain any chemical reactions.or explain the phenomenon (physical changes)behind each of your other observations.
(iii) Calculate the % crude caffeine that you recovered from tea.
(iv) Compare your % caffeine value to the reported value of caffeine content in tea leaves in Landgrebe (see page. 380 - 381). Explain any differences.
(v) Compare experimental IR spectrum to literature IR spectrum (provided). What can you conclude about the purity of your product.
(vi) Mass Spectrum of caffeine: (i) identify the base peak. (ii) identify the molecular ion peak. (iii) is the molecular ion peak the same as the base peak in the spectrum?
(Vii) Analysis of the pure caffeine spectrum - identify as many vibrational motions you can on the spectrum.