202
Chromatographic Troubleshooting
Introduction
This chapter is concerned with diagnosis: the process of going from
unexpected behavior of the HP 5890 SERIES II (hereafter referred to as
HP 5890) (symptoms) to the probable location of the difficulty (causes).
Problems arise from many causes. Some of these are:
Electronic or mechanical failure
Contamination in critical areas, such as detectors
Incorrect or inappropriate setpoints
Leaks, column or septum bleed, or other chromatographic difficulties
These may interact to a bewildering degree: For example, baseline
problems may arise from any of the above areas. Accordingly, this chapter
is organized by symptoms, with reference to most probable causes.
Baseline symptoms
Position
1. Baseline not at left (lower) part of chart:
Check the zero of your recording device: An attenuation or range
change during the run may be responsible.
Check TCD signal polarity.
2. Baseline position changes suddenly during the run:
This usually results from a range or attenuation change.
