Instrument - Iodide Chemical Ionization Mass Spectrometer
Iodide Chemical Ionization Mass Spectrometer
What is being measured:
Vapor phase oxidized and halogenated VOCs
Data recording software:
Data analysis software:
Igor Pro v6
Raw data time resolution:
Analysis data averaging:
Sensitivity to temperature (and correction method, if applicable):
Wall "memory" effects are minimized at higher temperatures i.e. there is a faster response time at higher sampled temperatures. No specific correction method is employed for the instrument readings, but the ion molecule reaction region (IMR) is maintained at 40C to minimize wall effects.
Sensitivity to relative humidity (and correction method, if applicable):
Instrument sensitivity to RH has been reported. We pass the reagent carrier gas (UHP N2) through deionized water before it passes to the IMR region so that it is humidified to a constant RH for all the sample flow.
Sample preparation method:
Sample residence time (chamber to instrument) (seconds):
Length of tubing (cm):
Instrument flow rate:
Tubing inner diameter:
Chemical identification method:
Iodide ions come into contact with compounds in sample stream in the ion molecule reaction region (IMR) of the CIMS. The I- + compound adducts pass through the time of flight (ToF) chamber, where m/z is proportional to ToF. Three calibrants are used for the mass-time of flight conversion: I-, IH2O-, I3-.
Data analysis method:
Gas calibration system is currently being tested.
Calibration drift estimate:
Uncertainty estimation method:
Link to supplemental information: