Concentrating Zone Plates (TLC, HPTLC, PLC)

MilliporeSigma’s concentrating zone plates are based on the different properties of two silica adsorbents: an inert, large-pore concentrating adsorbent where the samples are applied; and a selective separation layer. Independent of the shape, size or position of the spots, the sample always concentrates within seconds as a narrow band at the interface of the two adsorbents. In addition, the concentrating zone can serve as a clean-up step for analytes in complex matrices, such as oils and cosmetics. Suitable for TLC, HPTLC and PLC, the plates allow easy application of large volumes of diluted samples. The analytical TLC and HPTLC concentrating zone plates provide areas of 2.5 cm, whereas the concentrating zone of PLC plates is 4 cm in length.

Features and Benefits

• Quick and easy sample application
• Highly facilitated sample loading
• Better resolution due to focused bands
• Includes purification and concentration steps

Separation of Polycyclic Aromatic Hydrocarbons

The special HPTLC silica gel 60 RP-18 PAH concentrating zone plate is optimized for high-resolution separations of polycyclic aromatic hydrocarbons (PAH) according to DIN 38409-H13. These compounds result from pyrolysis or incomplete combustion of organic material. Main sources include the exhaust fumes of private and industrial furnaces, car exhaust, and tobacco smoke. Since some PAH are carcinogenic, maximum limits have been set for substances such as drinking water, and their determination is of great importance.

Application Examples

Stages of the development of a concentrating zone silica gel 60 PLC plate are shown below using a sample of lipophilic dyes with toluene as the mobile phase.
A. Sample Application	B. Concentration	C. Separation