Key components of TLC

1 TLC plate. The majority of TLC experiments are now carried out on ready-made plates, consisting of the absorbent (silica, alumina or alkyl-bonded silica), the support and an inert binder. Conventional TLC plates are normally 20 cm X 20 cm in size, have an absorbent layer of 100-250 jxm thickness, and are coated with 20 jiim particle-size material which can be obtained in differing pore sizes (important to polymer separation). Typically 1-5 p.1 of sample are applied. More recently, high-performance TLC plates have been developed which are smaller in size (10 cm x 10 cm) and are coated with smaller particle-size absorbants (5-15 p.m) to increase separating power. When such plates are used, sample loadings can be as little as 0.1-0.2 il. 

2 Sample application. Samples to be analysed by TLC must be applied to the layer so as not to degrade the efficiency of the layer. The sample aliquot 

---