miniaturized ultra high-mass resolution time-of-flight
TRANSCRIPT
Ion Source
DetectorDetector
Miniaturized ultra high-mass resolution time-of-flight mass spectrometer “infiTOF”
and applications for environmental analysis
Graduate school of engineering, Osaka University
Shuichi Shimma, PhD
(Gao L et al., Anal. Chem., 2008, 80, 7198-7205)
(HAPSITE system brochure)
(TORION Technologies HP)
Miniaturized mass spectrometersTRIDION9 GC-TMS
(TORION Technologies Inc)Mini 11
(Purdue Univ. )
HAPSITE system (Inficon)
38.1 cm x 39.4 cm x 22.9 cm (14.5 kg)Purdue Mini-12 (QuantIon source + Mini 11)
(Ouyang Z et al., Anal. Chem., 2009, 81, 2421-2425)
Summary of reported miniaturized instruments.
Q1. High mass resolution is unnecessary for on-site measurement ? Q2. High mass resolution cannot be available in miniMS ?
What kinds of instruments are suitable for high mass resolution ? (1) Magnetic sector, (2) FT instruments (FT-ICR and Orbitrap), (3) Time-of-Flight instruments.�
High mass resolution
Maximize flight time T
Maximize flight path length
Minimize peak width ΔT
Mass Resolution of TOF instruments
Mass Resolution： mΔ m = T
2 ΔT
Mass Resolution of TOF instruments
Mass Resolution： mΔ m = T
2 ΔT
❏ To extend the flight time T : Long flight path length
❏ To minimize the peak-width ΔT (FWHM)(1) Two-stage acceleration and time-lag focusing (Delayed Extraction) (2) Orthogonal acceleration (3) Ion mirrors (Reflectron) (4) Electric sectors
Straight Forward Way
(maXis http://www.bdal.com)
Dimensions: 800 x 1320 x 2850 mm Weight: 500 kg Mass resolution: 60,000 (these values from maXis brochure)
Photographs of “MULTUM-S II” system
Ion Source
MULTUM
Detector
45 cm 23 cm 64 cm35kg
TMPTMP
DiaphragmPump
DiaphragmPump
20 cm
20 c
m
Orbiting Sector
Orbiting Sector
InjectionSector
EjectionSector
Ion Selector
(a) (b)
Ion source: electron ionization Mass range: m/z 1 - 1000 (depend on ionization methods) Pressure in analyzer: typically 5x10-5 Pa (with diaphragm pump and TMP 70 Ls-1 (N2))
Shimma S et al. Anal. Chem., 82, 8456 (2010)
Commercialized as “infiTOF” (KANOMAX)
Operation of “MULTUM-S II” system (Zooming mode)
• Injection and ejection electrodes are synchronized with the ion source pulsing triggering.
• Injection electrode has to be in the on state while ions enter the analyzer, then has to be turned off before first ion (lightest ions) returns to it.
• Orbiting electrodes are constant, so orbiting ion can be held until ejection electrode is ON.
injectionejection
detector
(C)
Performance evaluations
(A) Mass resolution and peak width (N2), Mass resolution is linearly increased by changing number of cycles.
(B) Ion transmittance (N2), 98% ions survived in each cycle.
(C) Linear signal response (PFTBA) The dynamic range was 3 orders of magnitude.
Shimma S et al. Anal. Chem., 82, 8456 (2010)
Mass resolution
4He+. D2+. 4He+.
D2+.
Separation of doublets (direct injection of standard gas)
O+. or (O22+.)
CH4+.
N2+.
O2+.
Ar+.
O+. or (O22++..)
CH4+.
He and D2
O and CH4
Resolution 1000 at 10 cycle Low resolution
Low resolutionResolution 3200
at 6 cycle
43.5 43.6 43.7 43.8 43.9 44 44.1 44.2 44.3 44.4m/z
%
100
80
60
40
20
0
10 cycles
43.5 43.6 43.7 43.8 43.9 44 44.1 44.2 44.3 44.4m/z
%
100
80
60
40
20
0
43.99220 cycles
43.5 43.6 43.7 43.8 43.9 44 44.1 44.2 44.3 44.4m/z
%
100
80
60
40
20
0
43.990100 cycles
Mass resolution> 30,000
Separation of CO2&N2O doublet
CO2&N2O
N2OCO2
N2O
CO2
MULTUM-S II has a tunable mass resolution, and can work as a high performance gas monitor system.
Shimma S et al. Anal. Chem., 82, 8456 (2010)
CO2 and N2O are known as greenhouse gases.
Real-time monitoring of CO2 and N2O is required to elucidate the genera t ing mechan ism and investigate its trend of spread.
m/z of CO2 43.9898 N2O 44.0011 Δm: 0.0113
High mass resolution is required.
PCBs analysis using “GC-infiTOF”
Polychlorinated biphenyls: a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl. 209 congeners. Toxic compounds.
Conventional analysis methods for PCB congeners: 1. Gas chromatograph (GC)/ECD 2. GC/MS/MS, GC/QMS, GC/negative ion chemical ionization (NICI) 3. GC/high-resolution MS (resolution > 10, 000. Magnetic sector instruments)
(Cl)n(Cl)n
Structure of PCBs
GC-infitOF system (GC: Agilent 6890N)
Point of this application: GC-MULTUM-S II can be alternative to GC-magnetic sector system??
For GC/HRMS and GC/NICI, sample preparation is simple. ONLY dilution with n-hexane.
3,200
2,400
1,600
800
1000 1500 2000 2500 3000Scan1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.
Total ion chromatogram of 66 PCBs mixture.
By fast-GC technique, PCBs mixture can be analyzed within 5.5 min.
(Shimma S et al. J Env Moni 2012)
ConditionsColumn: Forte HT8 (12 m x 0.22 id, film 0.25 µm) Inlet temp.: 320°C Temp. program: 100°C (0.5min)->40°C min-1
320°C
Carrier gas: helium (70 cm s-1) Sample: 66 PCB mixture (mono, di-PCBs: 2 ppm others: 1 ppm)
High mass resolution mode (R > 10,000)
Hepta-CBTIC
Mass Chromatogramm/z 393.80
2050 2100 2150 2200 2250 2300 2350 2400
1 ppb was
detectable.
Limit of detection at 20 cycles
1 ppb of hepta-CB in the high mass resolution mode (R > 10,000)
Dielectric coolant analysis (hexane dilution)
In the low mass resolution mass spectra, signal peak and matrix peak were overlapped. Therefore, matrix interference were observed as a background noise in each mass chromatogram.
Mass resolution 300- Comparison of low- and high-resolution mode-
In the high mass resolution mass spectra, signal peak and matrix peak were clearly separated. High mass selectivity provided mass chromatogram without matrix interference even in diluted dielectric oil sample.
Dielectric coolant analysis (hexane dilution)
Mass resolution 10 000- Comparison of low- and high-resolution mode-
Summary
1. On-site mass spectrometry is the future application in MS. 2. To develop miniaturized MS instruments are essential. 3. High performance miniaturized TOF instrument
MULTUM-S II was developed. 4. Obtained mass resolution was > 30,000. 5. MULTUM-S II can work as the high performance
simultaneous gas monitoring system. 6. In the PCB analysis, MULTUM-S II is the alternative to
conventional HRMS instruments.