Common Method Descriptions
Common Method Descriptions
Normal Electrospray Ionization (ESI)
Using Exactive Plus (file names start with EX)
The experiments are performed on a Thermo Exactive Plus using a nanoflex source with off line adapter. 10 ul of solution is deposited into a New Objective econo picotip with microgel loading pipet tip from Fisher Scientific. This tip is placed in the nanosource using the offline adapter. A backing pressure is applied using an off line syringe to assure flow to the tip. A voltage of 1.0 to 2.5 kvolts is applied to the picotip. The typical settings are Capillary temp 320 oC. S-lens RF level is between 30-80 with an AGC setting of 1 E-6. The maximum injection time is set to 50 ms. Spectra are taking at 140,000 resolution at m/z 200 using Tune software and analyze with Thermo's Freestyle software.
Using Thermo LTQ-FTMS (file names start with FT)
The experiments are performed on a Thermo LTQ-FTMS using a nanospray source. 10 ul of solution is deposited into a New Objective econo picotip with microgel loading pipet tip from Fisher Scientific. This tip is placed in the nanosource using ths static nanospray probe. Nitrogen is used as a backing pressure to assure flow to the tip. A voltage of 1.0 to 2.5 kvolts is applied to the picotip. The typical settings are Capillary temp 200 oC, Capillary voltage 45 V, Tube lens voltage 100 V, and AGC 2 E5. Spectra are taking at 100,000 resolution using LTQ-Tune software and analyze with Xcalibur software.
Atmospheric Chemical Pressure Ionization (APCI)
Using Exactive Plus (file names start with EX)
The experiments are performed on a Thermo Exactive Plus using the the ion max source with the APCI probe. The sample is place on a melting point capillary and placed in a Ion Sense ASAP (Atmospheric Solid Analysis Probe)probe that is placed in the Ion max source in such a way as to have the gas from the APCI probe blowing on the capillary tube. The APCI probe uses Nitrogen gas at arbitrary units of 50 is heated to a temperature of 450 0 C. A discharge on a needle with a discharge current of 5 uA is used to ionize the sample. The typical settings are Capillary temp 320 oC. S-lens RF level is between 30-80 with an AGC setting of 1 E-6. The maximum injection time is set to 50 ms. Spectra are taking at 140,000 resolution at m/z 200 using Tune software and analyze with Thermo's Freestyle software.
Using Thermo LTQ-FTMS (file names start with FT)
The experiments are performed on a Thermo LTQ-FTMS using the the ion max source with the APCI probe. The sample is place on a melting point capillary and placed in a home made ASAP (Atmospheric Solid Analysis Probe)probe that is placed in the Ion max source in such a way as to have the gas from the APCI probe blowing on the capillary tube. The APCI probe uses Nitrogen gas at arbitrary units of 50 is heated to a temperature of 450 0 C. A discharge on a needle with a discharge current of 5 uA is used to ionize the sample. The typical settings are Capillary temp 275 0C, Capillary voltage 27 V, Tube lens voltage 125 V, and AGC 4 E5. Spectra are taking at 100,000 resolution using LTQ-Tune software and analyze with Xcalibur software.
Large Peptide ESI
Using Exactive Plus (file names start with EX)
Uses the same method as ESI. Plus Deconvolution is done using freestyle if the isotopes are resolved.
Using Thermo LTQ-FTMS (file names start with FT)
The experiments are performed on a Thermo LTQ-FTMS using a nanospray source. 10 ul of solution is deposited into a New Objective econo picotip with microgel loading pipet tip from Fisher Scientific. This tip is placed in the nanosource using ths static nanospray probe. Nitrogen at 20 psi is used as a backing pressure to assure flow to the tip. A voltage of 1.0 to 2.5 kvolts is applied to the picotip. The typical settings are Capillary temp 200 oC, Capillary voltage 49 V, Tube lens voltage 247 V, and AGC 5 E5. Spectra are taking at 100,000 resolution using LTQ-Tune software and analyze including deconvolution into a zero charge spectra are done with Xcalibur software.
Other Methods
Please contact the Director if you need any descriptions for the experiments preformed in the Mass Spectrometry center