ABSTRACT
A
c
itical
aspect of
the
gas chromatographic
(GC
system
is
a
lack
of interaction
between an inlet liner and the analytes which pass
through
it
Without the
apptopriate surface deactivation, analytes can
be
irreversIbly adsorbed and/or
temporarily
:retained
in
the
liner.
The
result ofwhich is poor,
inaccurate
chromatography reflectedas
tailing,
broad
or
absent
peaks.
For example,
in
an
analysis of semivolatile components, several analytes are prone
to inlet
liner
adsorption. 2,4-dinitrophenol, pentachlorophenol, N-nitroso-di-n-propylamjne,
and
hexach1orocyclopcntadiene are etten the first compounds
to
show signs of
implOper
inlet deactivation or
inlet
contamination. This is demonstrated as the relative
response ratios
of
these compounds are non-linear over a calibration curve and/or
below
the
mjnimum
required
values
dictated
by
the EPA method.
The
analysis
of
compounds
with
a
highly
basic
character
poses an equally difficult
challenge.
hnptuper
liner
surfaces
can
interact
with
basic analytes, resulting
in
adsorption
and
therefore chromatograms
with
severe peak tailing or an artificial lose
of
response. Ethanolamines
and
pclyamines are parti.cul.arly prone
to
this, and
selecting the
appropriate
liner
is
a
key
factor
in
accurate analyses.
Four diffetent types of
inlet
liners
will
be
evaluated
for
their
performance over a
broad
spectrum.
ofanalytes (i.e.,
from
highly
acidic
to
highly
basic
in
character).
Chromatographic
and
statistical results
will
be discussed
to
assist the
gas
chromatographer
in
the appropriate choice of
inlet
liner surface deactivation.
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