6 Operating in CI Mode
Setting Up Your MS to Operate in CI Mode
130 7000/7010 Series TQ GC/MS Operating Manual
Setting Up Your MS to Operate in CI Mode
Setting up your MS for operation in CI mode requires special care to avoid
contamination and air leaks.
• Always use the highest purity methane (and other reagent gases, if
applicable). Methane must be at least 99.9995% pure.
• Always verify the MS is performing well in EI mode before switching to CI.
• Ensure the CI source and GC/MS interface tip seal are installed.
• Ensure the reagent gas plumbing has no air leaks. This is determined in PCI
mode, checking for m/z 32 after the methane pretune.
• Ensure the reagent gas inlet line(s) are equipped with gas purifiers (not
applicable for ammonia).