Varian 450-GC, User Manual

Page: 195 / 205

Technical Tips
Varian, Inc. User Manual 450-GC Page: 459
Sympto m Cause Remedy
Check carrier gas flow.
Ghost peaks during temperature
programming, no injection made Contaminated Injector. Replace or clean Injector
insert.
Bake out Injector per
Section 4.
Leading peak Overloaded column.
Carrier gas flow restricted.
Decrease sample size or
increase dilution; use
column with thicker film.
Check column
connections and Injector
insert for obstructions.
Long solvent peak tail Injector temperature too high.
Injector leakage.
Column temperature too high.
Lower initial Injector
temperature.
Reseat column to glass
insert. See Section 3.
Decrease column
temperature.
No sample peak or peak too
small Leak at column inlet.
Syringe is leaking.
Broken column.
Injector is leaking.
Check for leaks (Section
4, paragraph 4.2).
Repair or replace syringe.
Replace or repair column.
Check or replace septum
or Injector.
Rising baseline when
temperature programming Column temperature limit
is exceeded.
Contamination.
Reduce maximum
temperature
Use column with
appropriate coating
thickness for sample. For
relatively non-volatile
compounds that require a
high retention
temperature, choose a
0.1
μ
coating thickness.
Check gas filters. Correct
all leaks, checking for the
following:
(a)make-up gas line union
(b)column-to-detector
connection
(c)detector insert-to-
detector crossover
connection
(d)detector crossover-to-