Page 199 - Illustrated Pocket Dictionary of Chromatography

202 TRIPLE POINT

compounds that are relatively strong acids that phosphoric and acetic
acids cannot effectively protonate. TFA’s solubility in a wide range of
solvents is also an advantage (compared with phosphates and
acetates). It should be noted that TFA is very volatile and will leave
solution over extended periods of time. Therefore, solvents contain-
ing low levels (e.g., 0.1% or less) should be freshly prepared and spar-
ingly degassed before use.

O

F 3 C OH
Trifluoroacetic acid

triple point The temperature and pressure at which a substance
is present at equilibrium as its solid, liquid, and gas. See SCF (super-
critical fluid).
Triple-quadrupole MS/MS Consists of three quadrupoles in
series. The first transmits ions (parent ions) in the same fashion as a
single-quadrapole instrument. The second MS contains a collision gas
that generates additional ions (daughter ions) from those selected by
the first quadrapole. These daughter ions are then sent to the third
quadrupole for final mass/charge filtering and detection.

tubing Used as a connector, with appropriate unions, for many
components in chromatographic systems: gas tank and GC, solvent
reservoir and pump head, column and detector, etc. Tubing is also
used to contain packing material for HPLC work.

tubing cutter Used to produce square-cut metal and plastic tubing
for use as connectors in chromatography instruments.