I am having trouble separating methyl methacrylate (MMA) from another peak. The interfering compound, appearing in the front, is identified by library as 3,3-dimethyl-2-butanone and it is inherent to the sample. MMA appears as the split/tailing peak. Both compounds have a boiling point around 100 C. Identification by mass spectrum is also challenging because both compounds share m/z values 41, 69, 85, and 100. However the interferent is often identified by m/z 57.1.
How can I separate these two peaks? If I change the detector settings to start looking at m/z 60 (essentially excluding the 57.1) will that improve anything?
INSTRUMENT CONTROL PARAMETERS: 1
-----------------------------------
Wed Jan 17 15:49:45 2024
Control Information
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Sample Inlet : GC
Injection Source : External Device
Mass Spectrometer : Enabled
Injection Location: Front
No Sample Prep method has been assigned to this method.
GC
GC Summary
Run Time 22.133 min
Post Run Time 0 min
Oven
Temperature
Setpoint On
(Initial) 32 °C
Hold Time 7 min
Post Run 70 °C
Program
#1 Rate 10 °C/min
#1 Value 70 °C
#1 Hold Time 0 min
#2 Rate 30 °C/min
#2 Value 320 °C
#2 Hold Time 3 min
Equilibration Time 0.25 min
Max Temperature 320 °C
Maximum Temperature Override Disabled
Slow Fan Disabled
Front SS Inlet He
Excluded from Readiness ***Excluded from Affecting GC's Readiness State***
Mode Split
Heater On 250 °C
Pressure On 17.909 psi
Total Flow On 22.02 mL/min
Septum Purge Flow On 3 mL/min
Pre-Run Flow Test Off
Gas Saver On 20 After 3 min mL/min
Split Ratio 10 :1
Split Flow 17.291 mL/min
Liner Agilent 5190-2293: 900 μL (Splitless, single taper, wool, Ultra )
Back PTV Inlet He
Mode Sleep
Pressure Off
Septum Purge Flow Off
Pre-Run Flow Test Off
Liner Agilent G1544-80730: 675 μL (Direct connect, single taper, bottom )
Column
Column #1
Flow
Setpoint On
(Initial) 1.7291 mL/min
Post Run 0.57353 mL/min
Column Information Agilent
Restek-Rxi5SilMS
Temperature Range -60 °C—350 °C (350 °C)
Dimensions 30 m x 250 μm x 0.25 μm
Column lock Unlocked
In Front SS Inlet He
Out PSD 2
(Initial) 32 °C
Pressure 17.909 psi
Flow 1.7291 mL/min
Average Velocity 34.759 cm/sec
Holdup Time 1.4385 min
Control Mode Constant Flow
Column #2
Pressure
Setpoint On
(Initial) 2 psi
Post Run 10 psi
Temperature Range -1 °C—325 °C (325 °C)
Dimensions 5 m x 200 μm x 0 μm
Column lock Unlocked
In PSD 2 He
Out MSD
(Initial) 32 °C
Pressure 2 psi
Flow 1.5224 mL/min
Average Velocity 109.14 cm/sec
Holdup Time 0.076352 min
Control Mode Constant Pressure
Column Outlet Pressure 0 psi
Front Detector FID
Excluded from Readiness ***Excluded from Affecting GC's Readiness State***
Makeup He
Heater On 300 °C
H2 Flow Off
Air Flow Off
Makeup Flow Off
Carrier Gas Flow Correction Constant Makeup and Fuel Flow
Flame Off
Detector Evaluation
Perform Detector Evaluation Test Off
Signal Selected No Signal Selected
Checkout Sample None
MSD Transfer Line
Temperature
Setpoint On
(Initial) 320 °C
Aux EPC 1,2,3
Aux EPC 1 N2
Pressure
Setpoint Off
(Initial) 10 psi
Post Run 10 psi
Excluded from Readiness ***Excluded from Affecting GC's Readiness State***
Aux EPC 2 N2
Pressure
Setpoint Off
(Initial) 10 psi
Post Run 10 psi
Excluded from Readiness ***Excluded from Affecting GC's Readiness State***
Aux EPC 3 N2
Pressure
Setpoint Off
(Initial) 10 psi
Post Run 10 psi
Excluded from Readiness ***Excluded from Affecting GC's Readiness State***
PSD 2
Excluded from Readiness ***Excluded from Affecting GC's Readiness State***
PSD Purge On 0 mL/min
PSD 2 He Supplies Column 2
Signals
Signal #1:
Description None
Signal #2:
Description None
Signal #3:
Description None
Signal #4:
Description None
Signal #5:
Description None
Signal #6:
Description None
Signal #7:
Description None
Signal #8:
Description None
GERSTEL MAESTRO
SYSTEM SETTINGS
Maestro Runtime : 22.13 min
GC Cool Down Time : 5.00 min
Cryo Timeout : 15.00 min
GERSTEL CIS
CIS : not used - use these parameters if it becomes 'used'
CRYO COOLING
Cryo Cooling : used
TEMPERATURE PROGRAM
Heater Mode : Standard
Liner Type : 013882-010-00 glass liner CIS4, baffled, non deactivated
Liner Max Temperature : 400 'C
Initial Temperature : -10 'C
Equilibration Time : 0.50 min
Initial Time : 0.50 min
Ramp 1
Rate : 12.00 'C/s
End Temp : 325 'C
Hold Time : 5.00 min
Ramp 2
Rate : 0.0 'C/s
Low Split : not used
GERSTEL MPS PREP
Sample Prep : used
PREP ACTION LIST
Action Method/Value Source Destination
============= =================== =================== ===================
GERSTEL MPS Liquid Injection
Syringe : 10ul 65mm USM
SAMPLE PARAMETERS
Sandwich : not used
Inj. Volume : 1.0 uL
Air Volume below : 0.0 uL
Inj. Speed : 50.00 uL/s
Fill Volume : 5.0 uL
Fill Strokes : 5
Fill Speed : 2.00 uL/s
Viscositiy Delay : 0 s
Eject Speed : 50.00 uL/s
Pre Inj. Delay : 0 s
Post Inj. Delay : 0 s
Inj. Penetration : 40.00 mm
Sample Tray Type : VT54/2-CVM
Bottom Sense : used
Fast Injection : used
CLEANING PARAMETERS
Preclean Sample : 2
Wash Station 1 : Pos1@Standard Wash 1
Preclean Solv.1 : 2
Postclean Solv.1 : 6
Clean Volume Solv.1 : 90 %
Fill Speed Solv.1 : 5.00 uL/s
Viscosity Delay Solv.1 : 0 s
Eject Speed Solv.1 : 50.00 uL/s
Information Solv.1 : Hexane
Wash Station 2 : Pos2@Standard Wash 1
Preclean Solv.2 : 0
Postclean Solv.2 : 0
Clean Volume Solv.2 : 70 %
Fill Speed Solv.2 : 5.00 uL/s
Viscosity Delay Solv.2 : 0 s
Eject Speed Solv.2 : 50.00 uL/s
MS Information
-- -----------
General Information
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Acquisition Mode : Scan
Solvent Delay (minutes) : 3.3
Tune file : D:\MassHunter\GCMS\1\5977\etune.u
EM Setting mode Gain : 5.000000
Normal or Fast Scanning : Normal Scanning
Trace Ion Detection : Off
Run Time (if MS only) : 23.67 minutes
[Scan Parameters]
Start Time : 3.3
Low Mass : 40
High Mass : 300
Threshold : 300
A/D Samples: : 4
[MSZones]
MS Source : 230 C maximum 250 C
MS Quad : 150 C maximum 200 C
Timed Events
----- ------
Number Events= 0
END OF MS ACQUISITION PARAMETERS
TUNE PARAMETERS for SN: US2018M021
---------------------------------
Trace Ion Detection is OFF.
34.593 : EMISSION
70.007 : ENERGY
3.192 : REPELLER
89.822 : IONFOCUS
22.672 : ENTRANCE_LENS
1665.995 : EMVOLTS
2022.2 : Actual EMV
5.00 : GAIN FACTOR
1873.000 : AMUGAIN
132.813 : AMUOFFSET
1.000 : FILAMENT
0.000 : DCPOLARITY
6.828 : ENTLENSOFFSET
9.002 : Ion_Body
3.506 : EXTLENS
-255.000 : MASSGAIN
-32.000 : MASSOFFSET
END OF TUNE PARAMETERS
----------------------
END OF INSTRUMENT CONTROL PARAMETERS
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