21
InjectionPort Liner
DrilledUnilinerw/ hole
There are two styles ofDrilledUniliner
®
liners, onewith a hole near the top, and a
secondwith a hole near the bottomof the liner. The choice of liner is dependent on
how closely the first compound elutes to the solvent peak. If the first compound
elutes near the solvent peak, as inMethod8270, the drilledUniliner
®
with the hole at
the bottomof the liner should be used. This allows all the solvent tobe flushedout of
the entire inlet liner, reducing any solvent tailing, which could interferewith the first
eluting compounds. The drilledUniliner
®
with the hole near the top of the linerworks
wellwhen the first compounds elute away from the solvent peak as in ethylene glycol
inwater, or chlorinated pesticide analysis.
TheDrilledUniliner
®
alsohelps eliminate injectionport discrimination for
the late elutingPAHs. This is shown in figures 5A and5B. Figure 5A shows the
difference between a pressure pulsed injectionversus constant flow for the single
gooseneck liner. Figure 5B shows the difference between theDrilledUniliner
®
and
single gooseneck liner under constant flow condition. TheDrilledUniliner
®
exhibits
the least amount of injectionport discrimination.
