Submitting Samples for Mass Spectrometry
Request Form (MSrequestform.pdf)(MSrequestform.docx)
1. Place your sample in a glass 1-dram vial with a PTFE-lined cap. If your sample is a NMR solution (D2O, CDCL3, or CCL4), put an aliquot (~20-50 µL) in a glass 1-dram vial with a PTFE-lined cap, and note that it is a NMR solution on the Request Form and on the vial label. If your sample is in a glass capillary (melting point tube) cut the capillary so that it fits inside a 1-dram vial with a PFTE-lined cap.
2. Fill out one Mass Spectrometry Request Form for each sample. Please use a black pen.
3. Enter the next log number from the logbook on the Request Form.
4. Enter your name, your lab director’s name, the ionization method requested, and the date in the logbook.
5. Tape your sample vial to the bottom of the Request Form, and place the Form in the refrigerator.
6. The mass spectrum and your remaining sample will be placed on the table in the hall outside of Room 2142 as soon as it has been run.
Submission Notes
1. Even if your sample is a solid, do not use vials with paper-lined caps. We often put samples in a solvent. Methanol and acetonitrile, for example, extract astonishing arrays of ions from non-PTFE-lined caps.
2. If your research group has a person trained and checked out to operate the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) instrument, it may be quicker to have that person run your sample than to wait for Instrument Center personnel to run it.
3. Ionization methods available:
- EI = electron impact
- ESI = electrospray ionization
- MALDI = matrix-assisted laser desorption/ionization
- ASAP-MS = Atmospheric Solids Analysis Probe™
ESI and MALDI work really well with compounds with functional groups that can be protonated or deprotonated in water and with compounds that form complexes with positive ions such as Na+, K+, Ag+, and Cu+2. Generally, compounds do not protonate/deprotonate and form metal ion complexes in an EI source, and generally ESI and MALDI do not produce lots of fragment ions like EI does. Remember, mass spectrometry detectors recognize positive or negative ions. They do not register neutrals. So any suggestions for how to ionize your neutrals will be appreciated. Please place your suggestions on your Request Form.
If you have any questions on how mass spectrometry samples are handled, please see me. If you are interested in being trained to operate the MALDI-TOF MS or the LCMS or the GCMS, please let me know.