L1 /
9
CH3041
GC II
• The sample (» 1 mL) is injected and swept
onto the column by the carrier gas (He) MP.
onto the column by the carrier gas (He) MP.
• Once on the column the lighter, low
b.p.,
low affinity components move quickly to the end of the column as bands and are
detected. The high MW, high b.p., high affinity compounds move slowly.
low affinity components move quickly to the end of the column as bands and are
detected. The high MW, high b.p., high affinity compounds move slowly.
Control of
the resolution is achieved by:
•1)
choice of the column SP “like
dissolves like”
eg. polar perfumes use polar Carbowax
eg. polar perfumes use polar Carbowax
•2)
temperature programming of the oven
eg. 25oC 10 mins, 25 - 325oC at 5oC/min
•3)
pressure programming of the column
