Page 150 - Illustrated Pocket Dictionary of Chromatography

150 PISTON SEAL

piston seal A component that forms a high-pressure leakproof seal
between the pump head and the piston. The piston seal is often man-
ufactured from chemical-resistant and compressible polymers. These
have an imbedded coil that applies pressure to the internal (piston)
and external surface (pump head).

Four different configurations of piston seals are shown here. They represent
different manufacturer systems. Note that the materials of construction vary as
well.

placebo See matrix blank.

planar chromatography A separation that is developed on a
support material that is essentially two dimensional, for example,
thin-layer chromatography. Also see TLC

plate (1) The component of a thin-layer chromatography product
that provides support for the sorbent material. The support material
is typically made from glass, plastic, or, less commonly, aluminum.
The types of phases used in TLC are the same as those used in HPLC,
but the particle size for TLC is typically larger. (2) See theoretical
plate, N.