What is a "Reverse Method"?
If you are experiencing difficulties troubleshooting a MOSH/MOAH analysis and would like to narrow down the source of the problem, the reverse method can be a useful diagnostic tool.
In the standard MOSH/MOAH method, the MOSH fraction is transferred to the front GC channel, while the MOAH fraction is transferred to the back GC channel.
If the issue occurs on only one GC channel and you would like to rule out problems with the LC system (including the LC valves on MPS), you can use the reverse method. This method directs the MOSH fraction to the back GC channel and the MOAH fraction to the front GC channel.
In other words, the reverse method simply swaps the GC channels used for the MOSH and MOAH fractions. If the problem follows the fraction, the issue is likely related to the LC system or sample preparation. If the problem remains on the same GC channel, the source is more likely within the GC system.
