Specifications

70 5975 Series MSD Troubleshooting and Maintenance Manual
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