Agilent Technologies 7250 Troubleshooting And Maintenance Manual page 47

2 General Troubleshooting
Table 3
Ions (m/z)
18, 28, 32, 44 or 14, 16
31, 51, 69, 100, 119, 131,
169, 181, 214, 219, 264, 376, 414,
426, 464, 502, 576, 614
31
43, 58
78
91, 92
105, 106
151, 153
69
73, 147, 207, 221, 281, 295, 355,
429
149
Peaks spaced 14 m/z apart
7250 Accurate-Mass Q-TOF Troubleshooting and Maintenance Manual
Common contaminants
Compound
H O, N
2
PFTBA and related ions
Methanol
Acetone
Benzene
Toluene or xylene
Xylene
Trichloroethane
Foreline pump oil or PFTBA
Dimethylpolysiloxane
Plasticizer (phthalates)
Hydrocarbons
Possible source
, O , CO or N, O Residual air and water, air leaks,
2 2 2
outgassing from Vespel ferrules
PFTBA (tuning compound)
Cleaning solvent
Cleaning solvent
Cleaning solvent
Cleaning solvent
Cleaning solvent
Cleaning solvent
Foreline pump oil vapor or
calibration valve leak
Septum bleed or methyl silicone
column bleed
Vacuum seals (O-rings)
damaged by high temperatures,
vinyl gloves
Fingerprints, foreline pump oil
47