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: shuichi@mass.phys.sci.osaka-u.ac.jp1 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

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.

(C) m/z 222.01

3,200

2,400

1,600

800

ScanMin.

(F) m/z 325.902,000

1,600

1,200

800

400

1000 1500 2000 2500 3000Scan1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.

(G) m/z 359.87

1,600

1,200

800

400

500 1000 1500 2000 2500 3000Scan1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.

(H) m/z 395.841,200

900

600

300

500 1000 1500 2000 2500 3000Scan1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.

(I) m/z 427.811,200

900

600

300

1000 1500 2000 2500 3000Scan1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.

(J) m/z 463.771,000

800

600

400

200

1000 1500 2000 2500 3000Scan1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.

(K) m/z 497.72

600

400

200

1000 1500 2000 2500 3000Scan1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.

(D) m/z 255.972,500

2,000

1,500

1,000

500

1000 1500 2000 2500 3000Scan1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0Min.

(B) m/z 188.04(A) TIC

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 5.0

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

100

221.0915

222.0103

223.0102

224.0132

225.0158226.0068

227.0019

%

254 256 258 260 262 m/z

100

80

60

40

20

255.9663

256.9773258.9679

259.9670

260.9839

290 295 m/z

%

100

80

60

40

20

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

1,600

1,200

800

400

500 1000 1500 2000 2500 3000Scan0 1 2 3 4 5Min.

325 330 m/z

%

100

80

60

40

20

323.8955

324.8996

325.9008

326.8881

327.8990

329.8812

355 360 365 m/z

%

100

80

60

40

20

357.8663

358.8720

359.8664

360.8772

361.8685

362.8635

363.8622

365.8720

390 395 400 405 m/z

%

100

80

60

40

20

391.8339

392.8391

393.8225

394.8096

395.8356

396.8094

397.8282

399.8380

401.8089

425 430 435 440m/z

%

100

80

60

40

20

425.8071

427.7929

429.8099

431.8038

433.7998

460 465 470 m/z

%

100

80

60

40

20

461.7767

463.7763

465.7697

467.7595

469.7469

495 500 505 m/z

%

100

80

60

40

20

493.7224

495.7438

497.7203

499.7526

501.7644

503.7255

186 188 190 192m/z

%

100

80

60

40

20186.1760187.1628

188.0628

189.0756

190.0516

191.2106

192.2005

193.2227

186 188 190 192 m/z

%

100

80

60

40

20

187.1804

188.1875

189.1930

190.1929

191.2021

192.2115

193.2252

220 225 m/z

%

100

80

60

40

20 219.2642

222.0398

223.0309

224.0369

225.0379226.0658227.2414

220 225 m/z

%

100

80

60

40

20

219.2605

220.2626

221.2660

222.2753

223.2678

224.3127

227.2148

m/z 188.06+-0.02

+-0.02

2,500

2,000

1,500

1,000

500

500 1000 1500 2000Scan0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5Min.

m/z 188.19

1,000

800

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500 1000 1500 2000Scan0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5Min.

m/z 222.04

2,000

1,600

1,200

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500 1000 1500 2000Scan0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5Min.

m/z 222.27

1,200

1,000

800

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500 1000 1500 2000Scan0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5Min.

(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

%

100

80

60

40

20

0

391.81

393.80395.80

397.80392

394 396

398

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