Agilent Technologies 5977B Series

76
3 CI Troubleshooting
No reagent gas peaks in NCI
• Reagent gases do not ionize in NCI; look for background ions instead.
• Verify tune parameters.
• If no background ions are visible, go back to methane PCI.
No PFDTD calibrant peaks in NCI
• Look for background ions: 17 (OH
–
), 35 (Cl
–
), and 235 (ReO3
–
).
• Verify tune parameters.
• Go back to methane PCI.
No sample peaks in NCI
• Look for background ions: 17 (OH
–
), 35 (Cl
–
), and 235 (ReO3
–
).
• Go back to methane PCI.
• Poor quality reagent gas (purity less than 99.99%).
Large peak at m/z 238 in NCI OFN spectrum
• Look for background ions: 17 (OH
–
), 35 (Cl
–
), and 235 (ReO3
–
).
• Find and fix your small air leak.