25
Gas Chromatography Troubleshooting Part I – Peak Shape Issues
by Shimadzu UK
While analytical instrumentation continues to evolve and develop, technology is not yet at the stage where total automation of analytical chemistry is possible. One such area where this is evident is in the field of troubleshooting and maintenance. Analytical techniques are more common than ever, and the number of analytical services available online, and instruments to perform them is booming. However, all these instruments have down time, whether this be due to quality control failures, routine maintenance, or general wear and tear. Therefore, all systems require an analytical mind to act as a ‘doctor’ when needed.
In this article, Shimadzu UK gives insights into effective troubleshooting for abnormal peak shapes in gas chromatography (GC), namely no peaks, fronting or tailing peaks, split peaks, broad peaks and ghost peaks. It will also provide hints and tips for successful troubleshooting. The next article (Part 2) shall investigate potential causes and solutions for other typical issues, including baseline issues, changes in response and retention time variability.
It can be incredibly frustrating when issues arise during a chromatographic run, and the cause and fix are unknown. Usually, there are a number of common problems which could have caused the issue. A basic knowledge of troubleshooting can help to reduce instrument downtime and identify potential issues to get a system back up and running without too much interruption.
Quite frequently, attempts to troubleshoot can be hindered by attempting to change too many variables at once, which can create confusion regarding the symptoms and causes. Alternatively approaches, such as using past experience can help to provide a good starting point for identifying the error, but it may not help in preventing the problem. The most appropriate troubleshooting approach is to investigate problems systematically and prevent errors from recurring.
The process of troubleshooting varies from system to system, but all should follow the same methodical process. Specific tests
are often performed, first to confirm the reproducibility of the error, and then slowly eliminating different parts of the instrument in order to chase the fault to its root cause. Troubleshooting can often feel like a game of hide and seek, with intermittent, random errors being the hardest find.
Hints and Tips
These key hints and tips can help towards beginning to identify errors:
o It is important to not overlook the obvious solutions first. For example,
check for disruptions to power and other connections to ensure the communication of the system is intact.
o Review the method parameters. Ensure the method has the correct gas flow rate, and the required column and liner are used. Although this sounds obvious, it is often ignored, with time spent trying other more complicated ‘fixes’.
o Record the sample preparation and ensure changes haven’t been made to solvent batches. Confirm the sample vial matches the position in the batch table.
o Good documentation can quickly and
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56
