Polychlorinated Biphenyls (PCB’ s) Analysis using Miniaturized High-resolution Time-of-Flight Mass Spectrometer “MULTUM-S II” Shuichi SHIMMA 1 , Shinichi MIKI 2 , Michisato TOYODA 2,3 E-mail: [email protected] 1 Venture Business Laboratory, Osaka University; 2 MSI Tokyo Inc.; 3 School of Science, Osaka University Ion Source MULTUM Detector 45 cm × 23 cm × 64 cm 35kg TMP TMP Diaphragm Pump Diaphragm Pump 20 cm 20 cm Orbiting Sector Orbiting Sector Injection Sector Ejection Sector Ion Selector ion source injection sector injection to MULTUM ejection from MULTUM detection of ions Number of cycle is controlled by timing of ejection sector multi-turn ejection sector 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 experimental conditions were evaluated using hepta-CB ( 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 3000 Scan 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (C) m/z 222.01 3,200 2,400 1,600 800 Scan Min. (F) m/z 325.90 2,000 1,600 1,200 800 400 1000 1500 2000 2500 3000 Scan 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (G) m/z 359.87 1,600 1,200 800 400 500 1000 1500 2000 2500 3000 Scan 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (H) m/z 395.84 1,200 900 600 300 500 1000 1500 2000 2500 3000 Scan 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (I) m/z 427.81 1,200 900 600 300 1000 1500 2000 2500 3000 Scan 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (J) m/z 463.77 1,000 800 600 400 200 1000 1500 2000 2500 3000 Scan 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (K) m/z 497.72 600 400 200 1000 1500 2000 2500 3000 Scan 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (D) m/z 255.97 2,500 2,000 1,500 1,000 500 1000 1500 2000 2500 3000 Scan 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. (B) m/z 188.04 (A) TIC 3,200 2,400 1,600 800 1000 1500 2000 2500 3000 Scan 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 1000 1500 2000 2500 3000 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Min. 220 222 224 226 228 m/z 100 221.0915 222.0103 223.0102 224.0132 225.0158 226.0068 227.0019 % 254 256 258 260 262 m/z 100 80 60 40 20 255.9663 256.9773 258.9679 259.9670 260.9839 290 295 m/z % 100 80 60 40 20 289.9387 290.9303 292.9187 293.9374 294.9609 295.9296 190 m/z % 100 188.0414 189.0447 190.0246 191.0391 (E) m/z 289.94 1,600 1,200 800 400 500 1000 1500 2000 2500 3000 Scan 0 1 2 3 4 5 Min. 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 425 430 435 440 m/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 186 188 190 192 m/z % 100 80 60 40 20 186.1760 187.1628 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 225.0379 226.0658 227.2414 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 2000 Scan 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Min. m/z 188.19 1,000 800 600 400 200 500 1000 1500 2000 Scan 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Min. m/z 222.04 2,000 1,600 1,200 800 400 500 1000 1500 2000 Scan 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Min. m/z 222.27 1,200 1,000 800 600 400 200 500 1000 1500 2000 Scan 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Min. (A) (B) (C) (D) BG BG (mz 188.19+-0.02) BG (mz 222.27+-0.02) BG 1 3 208 206 209 IUPAC# 194 195 199 202 203 205 IUPAC# 209 IUPAC# 1 3 IUPAC# 206 208 IUPAC# 170 174 178 180 187 188 189 IUPAC# 138 149 153 155 156 157 162 167 169 IUPAC# 87 95 99 101 104 105 110 111 114 118 123 126 IUPAC# 44 49 52 54 57 66 IUPAC# 18 19 28 31 70 74 77 78 79 81 33 35 37 38 IUPAC# 4 8 9 10 11 12 15 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 388 390 392 394 396 398 400 402 390 392 394 396 398 400 402 m/z m/z % 100 80 60 40 20 0 391.81 393.80 395.80 397.80 392 394 396 398 400 402 2 cycles (low mass resolution) 20 cycles (high mass resolution) Δm = 0.038 Resolution ~11,000 (m/z 393.8) (C) (D) PCB-180 TIC Mass Chromatogram m/z 393.80 2050 2100 2150 2200 2250 2300 2350 2400 (E) 1 ppb was detectable. 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: 100 O C (0.5 s) -> 40 O C/min->320 O C Inlet : 320 O C 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