User`s guide

Sampling Techniques
337
These inserts are highly recommended for solid samples, such as
drugs and foods such as spices, flour and coffee.
In the case of solid, resinous or liquid samples, use a preliminary
adsorbent bed in the tube when necessary. This will ensure that none
of the matrix material or other high-boiling compounds migrate into
the gas lines of the system.
Sampling Liquids and Emulsions
When you are sampling liquids and emulsions an adsorbent bed
should be used as a precolumn inside the tube to retain the sample
matrix or high boiling components, if required. Examples include
water-based paints and medicinal syrups.
Figure 103 Sampling Liquids and Emulsions
Sampling Resins and Ointments
Examples include epoxy resin and a range of pharmaceutical
ointment preparations. An adsorbent bed should be used as a
pre-column inside the tube as shown, to retain the sample matrix or
high boiling components.
Take care not to completely plug the carrier gas flow with the
sample.
CAUTION
Do not heat tubes containing PTFE inserts to temperatures
greater than 225°C.
Adsorbent BedPTFE Insert
Stainless Steel Tube
Gauze Rin
g
Glass Wool
Sample injected
or weighed into tub
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