polychlorinated biphenyls (pcb’ s) analysis using ...polychlorinated biphenyls (pcb’ s) analysis...
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Polychlorinated Biphenyls (PCB’ s) Analysis using Miniaturized High-resolution Time-of-Flight Mass Spectrometer “MULTUM-S II”
Shuichi SHIMMA1, Shinichi MIKI2, Michisato TOYODA2,3
E-mail: [email protected] Venture Business Laboratory, Osaka University; 2 MSI Tokyo Inc.; 3 School of Science, Osaka University
Ion SourceMULTUM
Detector
45 cm × 23 cm × 64 cm35kg
TMPTMP
DiaphragmPump
DiaphragmPump
20 cm
20 c
m
Orbiting Sector
Orbiting Sector
InjectionSector Ejection
Sector
Ion Selector
ionsource
injectionsector injection
to MULTUM
ejectionfrom MULTUM
detection of ionsNumber of cycle is controlled bytiming of ejection sector
multi-turnejectionsector
DAQ
[Purpose] To evaluate the performance of a miniaturized high-resolution time-of-flight (TOF) mass spectrometer “MULTUM-S II” for PCB’ s analysis.[Experimental methods] Mass resolution, limit of detection (LOD), linearity and other e x p e r i m e n t a l c o n d i t i o n s w e r e e v a l u a t e d u s i n g h e p t a - C B ( 2,2’ ,3,4,4’ ,5,5’ -heptachlorobiphenyl). Under optimized conditions, comprehensive native PCB mixture (66 PCBs mix) was used for establishing Fast-GC method.[Results] At 20 cycles, mass resolution of 8,000~10,000 was achieved, and LOD was 1ppb, and linearity was 2.5 orders of magnitude. In the high-resolution Fast-GC method, PCB mixture was able to measure within 5 minutes. Furthermore, background interfarence peaks were clearly separated even in the miniaturized mass spectrometer (MS).
Overview Block diagram of timing control
Experimental section
Conclusion
Performance evaluation
Comprehensive 66 PCBs mixture Analysis by Fast-GC
Affect of Interference of Dielectric Fluides in Coolant
Reference
Introduction
MULTUM-S II
3,200
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(C) m/z 222.01
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ScanMin.
(F) m/z 325.902,000
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(G) m/z 359.87
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(H) m/z 395.841,200
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(I) m/z 427.811,200
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(J) m/z 463.771,000
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(K) m/z 497.72
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(D) m/z 255.972,500
2,000
1,500
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(B) m/z 188.04(A) TIC
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1000 1500 2000 2500 30001.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.
220 222 224 226 228m/z
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221.0915
222.0103
223.0102
224.0132
225.0158226.0068
227.0019
%
254 256 258 260 262 m/z
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255.9663
256.9773258.9679
259.9670
260.9839
290 295 m/z
%
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289.9387
290.9303 292.9187
293.9374
294.9609295.9296
190 m/z
%
100188.0414
189.0447
190.0246
191.0391
(E) m/z 289.94
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325 330 m/z
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323.8955
324.8996
325.9008
326.8881
327.8990
329.8812
355 360 365 m/z
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357.8663
358.8720
359.8664
360.8772
361.8685
362.8635
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390 395 400 405 m/z
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391.8339
392.8391
393.8225
394.8096
395.8356
396.8094
397.8282
399.8380
401.8089
425 430 435 440m/z
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425.8071
427.7929
429.8099
431.8038
433.7998
460 465 470 m/z
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461.7767
463.7763
465.7697
467.7595
469.7469
495 500 505 m/z
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493.7224
495.7438
497.7203
499.7526
501.7644
503.7255
186 188 190 192m/z
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20186.1760187.1628
188.0628
189.0756
190.0516
191.2106
192.2005
193.2227
186 188 190 192 m/z
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187.1804
188.1875
189.1930
190.1929
191.2021
192.2115
193.2252
220 225 m/z
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20 219.2642
222.0398
223.0309
224.0369
225.0379226.0658227.2414
220 225 m/z
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219.2605
220.2626
221.2660
222.2753
223.2678
224.3127
227.2148
m/z 188.06+-0.02
+-0.02
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m/z 188.19
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m/z 222.04
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m/z 222.27
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(A) (B) (C)
(D)BG
BG (mz 188.19+-0.02)
BG (mz 222.27+-0.02)BG
1 3
208
206
209
IUPAC#194195199202203205
IUPAC#209
IUPAC#13
IUPAC#206208
IUPAC#170174178180187188189
IUPAC#138149153155156157162167169
IUPAC#879599101104105
110111114118123126
IUPAC#444952545766
IUPAC#18192831
707477787981
33353738
IUPAC#48910
111215
Fig. 5 Chromatograms of 66 PCBs mixture measured with GC-MULTUM. (A) Total ion chromatogram (TIC), (B)~(K) mass chromatogram from mono-CBs to deca-CB. All components were detected within 5 mins. Typical mass spectrum is displayed as an inset. IUPAC # are ingredients of analyte ( 66 PCBs in EC-5433).
Fig. 6 Affect of background interference using diluted dielectric fluids (PCB mix was spiked).(A) mono-CBs and (B) di-CBs. Comparing signal spectra and background spectra, target signal peaks were clearly separated from interference peak.(C) Mass chromatogram of mono-CBs and (D) di-CBs. HRSIMS (+-0.02 Da) could provide correct chromatogram w/o interference.
1. MULTUM-S II can provide HRSIMS data.2. In 20 cycles, mass resolution was 10,000 and LOD was 1 ppb.3. High-resolution mass spectra were beneficial for mixture analysis with brief preparation.
1. Shimma S et al. Anal. Chem., 82, 8456 (2010)
In our laboratory, a miniature multi-turn TOFMS was constructed and named “MULTUM-S II (INFITOF)” . This instrument basically consists of four electric sectors and two additional electric sectors for the purpose of ion injection/ejection. Accelerated ions traverse the figure of eight flight orbit many times. As a result of infinite flight length, higher mass resolution is available in the miniaturized MS. The size and weight of the system is 234 mm x 456 mm x 640 mm and 36 kg (including vacuum pump and electric circuits). High-resolution selected ion monitoring (HRSIM) provides sensitivity and selective detection for compounds of environmental interest such as PCB’ s. The analysis as traditionally carried out by using magnetic sector mass spectrometers is highly effective. However, setup and method development can be complicated, requiring careful programming of SIM target masses, lock masses, and retention time groups. Magnetic sector mass spectrometers with a resolving power of 10,000 or greater tend to be large and expensive. TOFMS is an attractive alternative because there is little or no tradeoff between high resolution and high sensitivity. However, previous commercially available GC/TOFMS systems are not offered with a resolving power of 10,000 or greater. The MULTUM-S II is well suited for PCB analysis. The system is compact, portable, and capable of achieving a resolving power of > 30,000 [1]. By acquiring high-resolution mass spectra in segments, method development is made easier.
between 15V and 20 V.
x9 higher
388 390 392 394 396 398 400 402 390 392 394 396 398 400 402m/zm/z
%
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391.81
393.80395.80
397.80392
394 396
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400402
2 cycles (low mass resolution) 20 cycles (high mass resolution)
Δm = 0.038
Resolution ~11,000(m/z 393.8)
(C) (D)
PCB-180TIC
Mass Chromatogramm/z 393.80
2050 2100 2150 2200 2250 2300 2350 2400
(E)
1 ppb wasdetectable.
Fig. 4 (A) Variation of peak intensity by changing ionization voltage. (B) Signal response curve from 0.01 ppm and 1 ppm. Comparison of mass spectra of PCB-180-TP. (C) 2cycles (low mass resolution < 400) and (D) 20 cycles (high mass resolution ~11,000). (E) TIC and mass chromatogram of m/z 393.8 in 1 ppb.
Fig. 2 Photograph of GC-MULTUM system.
Fig. 3 Chemical structure of PCBs.
Fig. 1 Photograph of MULTUM-S II. (A) Outside the system and (B) inside the analyzer.
(Cl)n(Cl)n
[Material and methods]Analyte C-180S-TP (Hepta-CB, Accu standard inc.) Comprehensive 66 PCBs mixture (EC-5433, CIL) Dielectric fluids in coolant diluted by n-hexane. PCB mixture was spiked into 1000-fold diluted fluids.GC condition GC: Agilent 6890N Column: FORTE HT8 (SGE) 12 m x 0.22 mm I.D. x 0.25 um film Oven: 100OC (0.5 s) -> 40OC/min->320OC Inlet : 320OC Splitless (purge time 0.5 sec) Sample injection : 1 uL (1 ppb to 1 ppm) MS condition Instrument: GC-MULTUM system (Fig. 2) Ionization: EI (18 ~ 20 eV, see below)Measurement mode: multi-segment (m/z 180~505 in 10 segments) DAQ: 0.1 sec (10 spectra/sec)Results and Discussion
(A)
(B)
2.5 orders of magnitude