THIN LAYER CHROMATOGRAPHY (TLC)
Mr. Shaise Jacob
Faculty, Nirmala College of Pharmacy
• There are two basic types of chromatography
• Liquid includes TLC and high performance liquid chromatography (HPLC)
• TLC is a form of liquid chromatography consisting of:
– A mobile phase (developing solvent) and
– A stationary phase (a plate or strip coated with a form of silica gel)
– Analysis is performed on a flat surface under atmospheric pressure and room temperature
• Michael Tswett is credited as being the father of liquid chromatography. Tswett developed his ideas in the early 1900’s.
• The two most common classes of TLC are:
– Normal phase
– Reversed phase
• Normal phase is the terminology used when the stationary phase is polar; for example silica gel, and the mobile phase is an organic solvent or a mixture of organic solvents which is less polar than the stationary phase.
• Reversed phase is the terminology used when the stationary phase is a silica bonded with an organic substrate such as a long chain aliphatic acid like C-18 and the mobile phase is a mixture of water and organic solvent which is more polar than the stationary phase.
THIN LAYER CHROMATOGRAPHY
Chromatography is used to separate mixtures of substances into their components. Similar to P.C, except that a thin layer of some inert material, i.e. Aluminium oxide, mag.oxid. , sili.oxide is used instead of paper.
• A layer of any one of these oxide is made from a slurry of power in a suitable inert solvent.
• Slurry is spread over a flat surface ( glass, metal or rigid plastic ) & dried