Two modes of operation

The JetClean operation can be applied in one of two modes:

• Clean Only mode – In this mode, the hydrogen is introduced into the system after the sample(s) have been processed. To use this mode you will create a new JetClean "Clean Only" method that will be used in this process. Your existing sample processing methods will remain unchanged.
• Acquire & Clean mode – In this mode, samples are analyzed via GC/MS EI while a small amount of hydrogen is simultaneously introduced into the ion volume to remove and reduce contaminants. To use this mode, you would modify your existing processing methods to include a low flow of hydrogen suitable to your application. (See Create and run a GC/MS JetClean Acquire and Clean method for details.)

Which Mode Should You Use?

To decide which mode is best for you, you must consider the variables specific to your system, such as sample type, cleanup effectiveness, and the analyte’s chemistry for example. Additionally, you must evaluate the impact each mode would have on your work flow. Although each situation is different, some of the major items to consider are listed below.

1. What compounds are you analyzing?

Polar compounds, compounds containing oxygen, nitrogen, sulphur, or phosphorus, may react with trace (trickle) hydrogen flow provided by the JetClean process to compromise your detection limits or spectral matches. In this case, the Acquire & Clean mode may not be acceptable. The Clean Only mode may be a better solution.

Non-polar compounds, and other highly stable compounds (PAHs, PCBs, etc.) on the other hand, will have limited reactivity in hydrogen, and therefore may work well with the Acquire & Clean mode.

2. Will you need to modify your Standard Operating Procedures?

When you use the Acquire & Clean mode, you will need to modify your GC/MS analytical methods by including hydrogen during sample processing. If your methods are included in validated SOPs, you may, therefore, need to modify and revalidate your SOPs.

On the other hand, the Clean Only mode will not require a new method, and, depending on your in-house operations, it may only be an addition to your system maintenance SOPs. However, the existing processing methods and SOPs could remain unchanged, and would not need to be revalidated.

Other considerations will become clear as you gain an understanding of JetClean as it applies to your application.