Tuesday, 26 May 2015

Project 2: Extraction of Caffeine from Beverages & Extraction and Identification of Artificial Colours

A) Project 2A Title:        Extraction of Caffeine from Beverages
Project Source:         School of Physical and Mathematical Sciences (SPMS)
Project Supervisor:  Dr Alessandra Bonanni
Teacher Advisors:    Mr Ng Guohui <ng_guohui@sst.edu.sg>

In the first part of this project, we will be extracting caffeine from tea. We will be using the following techniques that we do not usually encounter in school:
  1. Buchner filtration
  2. Solvent extraction
  3. Distillation using a rotary evaporator
  4. Detection using IR spectrophotometer
Caffeine is a type of organic weak base called an alkaloid and is found naturally in tea, coffee and kola nuts. It is in the same category as cocaine, strychnine, morphine, piperine and quinine.

B) Project 2B Title:        Extraction and Identification of Artificial Colours
Project Source:         School of Physical and Mathematical Sciences (SPMS)
Project Supervisor:  Dr Alessandra Bonanni
Teacher Advisors:    Mr Ng Guohui <ng_guohui@sst.edu.sg>

In the second part, we will be extracting and identifying artificial colours

Synthetic food colourants have an important role in determining the appeal of most foods. They are mainly used to enhance appearance rather than provide nutritional value, increase shelf life or safety. Food colourants are added to foods at low concentrations. It is necessary to extract and concentrate enough colourants for analysis.

We will be using wool, which is made of protein and is a binding agent, to extract the colourants. At a low pH level, the wool will be positively charged while the colourant molecules will be negatively charged at a low pH level. This will create an electrostatic binding with the wool protein. Separation and identification is performed by thin layer chromatography.