Development of a Novel Mass Spectrometric ... - Jacobs University

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Results and Discussion After identifying the chemical content in the positive ion mode of APCI-TOF-MS method, I shifted the method to the negative polarity to explore any potential compounds preferably ionised under negative APCI-TOF-MS 3.4.3 Identification of Polychlorinated Biphenyls (PCBs) in (-) APCI-TOF- MS The waste mixture was measured again by direct injection using this time negative (-) APCI-TOF-MS method. The mass spectrum observed in figure 3-26 revealed a class of polychlorinated compounds which demonstrated chlorine isotope patterns. Tetrachlorobiphenyl (1) at m/z 272.9, pentachlorobiphenyl (2) at m/z 306.9, hexachlorobiphenyl (3) at m/z 340.9, heptachlorobiphenyl (4) at m/z 374.8 and octachlorobiphenyl (5) at m/z 408.8 were identified by the (-) APCI method. This identification was based on a rational study of a PCB Congener Mix under the same (-) APCI conditions. The PCBs components within the standard mix produced (M-Cl+O) – ions as shown in figure 3-27. This finding wasn’t surprising as PCBs have been previously reported to ionize with the same fashion under APCI conditions. 111,112 The selectivity of ionisation is actually the significant observation. We tested the highest chlorinated PCB, decachlorobiphenyl (M= 498.66 g/mole) which was found to produce an (M-Cl+O) – ion at m/z 478.7 as shown in figure 3-28. A simulated isotope pattern for decachlorobiphenyl which is embedded in figure 3-28 was provided by Bruker Software. The latter figure shows that the measured and simulated isotope patterns are identical. However the (-) mass spectrum of the waste extract comprises also high mass chlorinated compounds. These compounds could be assigned as chlorinated alkanes or chlorinated aromatic hydrocarbons. Nevertheless the Bruker software of the TOF- MS suggested a chlorine content of these compounds according to their isotope patterns shown in figure 3-26. Small PCBs containing capacitors in household appliances and PCB-containing sealants for buildings within light shredder waste fraction would be the sources of these PCBs. 63
Results and Discussion Intens. [%] 100 2 306.9 3 340.9 Cl 6 450.9 -MS 80 60 40 20 0 Cl 7 484.8 283.3 4 1 374.8 420.8 473.3 Cl 6 270.9 5 Cl 5 Cl8 576.6 435.8 520.8 Cl 8 Cl 7 658.5 Cl 10 736.4 632.7 300 350 400 450 500 550 600 650 700 m/z Figure 3-26 (-) APCI mass spectrum showing identified PCBs in waste sample Intens. [%] 100 C 12 H 6 OCl 4 C 12 H 5 OCl 5 306.9 340.9 -MS 80 60 40 283.3 C 12 H 4 OCl 6 374.8 C 12 H 3 OCl 7 408.8 473.3 20 0 321.9 355.9 275 300 325 350 375 400 425 450 475 500 m/z Figure 3-27 (-) APCI mass spectrum of PCBs Congener Mix Intens. [%] 100 478.7 -MS 80 60 476.7 480.7 40 20 474.7 482.7 484.7 0 455 460 465 470 475 480 485 490 495 500 m/z Figure 3-28 (-) APCI mass spectrum of decachlorobiphenyl standard (C 12 OCl 9 ) with simulated isotope pattern as suggested by Bruker Software 64
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Development of a Novel Mass Spectro
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Declaration of Authorship I ,Nadim
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This work has been carried out unde
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Contents Contents Declaration of Au
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List of Figures List of Figures Fig
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List of Figures Figure 3-39 MS 2 fr
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List of Tables List of Tables Table
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Abbreviations Abbreviations APCI AP
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Abbreviations UV VGOs VOCs VRs ultr
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Introduction Analytical chemistry h
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Introduction 1.2 Presence and Fate
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Introduction aliphatic hydrocarbons
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Introduction Figure 1-1 Examples of
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Introduction Figure 1-2 Range of io
Page 29 and 30: Introduction fractions. 42 Another
Page 31 and 32: Introduction 1.3.5 APLI Other crude
Page 33 and 34: Introduction products). Other molec
Page 35 and 36: Introduction Other studies performe
Page 37 and 38: Introduction APLI-FT ICR-MS Crude o
Page 39 and 40: Introduction spectrometry in as muc
Page 41 and 42: Introduction catalytic processing t
Page 43 and 44: Introduction Figure 1-6 Kendrick ma
Page 45 and 46: Introduction including determinatio
Page 47 and 48: Introduction 1.5 Scope and Signific
Page 49 and 50: Experimental e) Other model mixture
Page 51 and 52: Experimental 2.2.2 Preparation of O
Page 53 and 54: Experimental 2.4 Graphical Presenta
Page 55 and 56: Results and Discussion experiment.
Page 57 and 58: Results and Discussion Intens. [%]
Page 59 and 60: Results and Discussion common featu
Page 61 and 62: Results and Discussion 3.2 APCI-TOF
Page 63 and 64: Results and Discussion These compou
Page 67 and 68: Results and Discussion Ions were pr
Page 71 and 72: Results and Discussion procedure ba
Page 75 and 76: Results and Discussion to produce m
Page 77 and 78: Results and Discussion 519.5863 519
Page 79: Results and Discussion Higher mass
Page 87 and 88: Results and Discussion isolated fro
Page 93 and 94: Results and Discussion 3.4.5 Tandem
Page 97 and 98: Results and Discussion injected int
Page 101 and 102: Results and Discussion 3.4.8 Quanti
Page 103 and 104: Results and Discussion Int. x 10000
Page 105 and 106: Results and Discussion Table 3.6 Qu
Page 107 and 108: Results and Discussion assessment o
Page 109 and 110: Results and Discussion hydrocarbons
Page 117 and 118: Results and Discussion of n-alkanes
Page 119 and 120: Results and Discussion flow (in I2)
Page 121 and 122: Results and Discussion Other intere
Page 123 and 124: Results and Discussion Figure 3-80
Page 125 and 126: Results and Discussion KMD 2.4 2.2
Page 127 and 128: Results and Discussion KMD 1.1 1 Le
Page 129 and 130: Results and Discussion 3.6.4 Asphal
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Conclusions In conclusion we could
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References References 1. Fay, R. M.
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References 23. Colavecchia, M. V.,
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References 47. Dzidic, I., Petersen
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References Hydroconversion Processe
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References 91. Golovlev, V. V., All
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Appendix Light shredder waste Meas.
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419.4592 C 30 H 59 419.4611 4.6 421
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Liqui Moly car motor oil Meas. m/z
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345.3511 C 25 H 45 345.3516 1.5 349
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