Page 91 - Illustrated Pocket Dictionary of Chromatography

FRIT 87

Fluorophenyl bonded phases
F F
R'
R'
Surface Si O Si CH 2 CH 2 (CF 2 ) 7 CF 3 Surface Si O Si (CH 2 ) n F
R R
F F
n = 0-3
Heptadecafluorodecyl bonded phase
Perfluorophenyl bonded phase

fluorophore A functional group that will fluoresce when the
proper wavelength radiation is used to excite it.

Fresnel refractive index detector The Fresnel RI detector uses
a prism gasket that creates two separate cells and a plate. The inci-
dent beam is split and sent through the two cells, one of which con-
tains the static reference solution (often the mobile phase). The other
goes through the flowing mobile-phase cell. The signals are subtracted
from one another, and the result is recorded as the detector output.
This type of RI is the most sensitive, but separate prisms must be used
in order to cover the entire RI range (i.e., changed).

frit A porous component often constructed from stainless steel or
titanium that is placed at the top and bottom of packed columns and
holds the packing bed in place. Frits are also used in in-line filters.

Frits are porous membranes typically constructed from stainless steel or titanium.
They are available in a wide range of diameters, thicknesses, and porosities.
Column frits are used to keep the packing bed in place. Frits are used in in-line
filters to trap particulates.