Thermogravimetric analyzer/atmospheric pressure chemical ionization tandem triple quadrupole mass spectrometer system for evolved gas analysis

Prime, R. Bruce; Shushan, Bori

doi:10.1021/ac00186a004

Cited by 26 publications

(14 citation statements)

References 22 publications

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“…The generation of molecular ions, instead of an intense fragment pattern, reduces the complexity of the mass spectra and allows for an easier molecular assignment. In previous studies, we applied various soft ionization techniques for thermal analysis, such as photoionization ,− and chemical ionization. − With the selection of a particular soft ionization technique, control of selectivity can be achieved. In the case of resonance-enhanced multiphoton ionization (REMPI), aromatic compounds are selectively ionized, , whereas atmospheric pressure photoionization (APPI) reveals a high ionization efficiency for aromatic and sulfur-containing species and atmospheric pressure chemical ionization (APCI) reveals a high ionization efficiency for medium-polar and polar constituents. ,− We applied TA with soft ionization mass spectrometric detection for a wide range of applications, e.g., nut and coffee roasting, ,, crude oils, ,, biomass/tobacco pyrolysis, ,, elemental sulfur evaporation, polymers, and dissolved organic matter .…”

Section: Introductionmentioning

confidence: 99%

Combination of Different Thermal Analysis Methods Coupled to Mass Spectrometry for the Analysis of Asphaltenes and Their Parent Crude Oils: Comprehensive Characterization of the Molecular Pyrolysis Pattern

et al. 2017

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In this study, the asphaltene and corresponding crude oil, distributed within the Asphaltene Characterization Interlaboratory Study for PetroPhase 2017, were characterized on the molecular level. For this purpose, three different thermal analysis mass spectrometry hyphenations with five diverse ionization techniques varying in selectivity were deployed: (1) thermal desorption/pyrolysis gas chromatography electron ionization (TD/Pyr–GC–EI–QMS), (2/3) thermogravimetry single-photon/resonance-enhanced multiphoton ionization time-of-flight (TG SPI/REMPI TOF–MS), and (4/5) thermogravimetry atmospheric pressure photo-/chemical ionization ultrahigh-resolution mass spectrometry (TG APPI/APCI FT-ICR MS). For the investigated C7 asphaltene, no mass loss was detected at <300 °C and the pyrolysis phase was dominant, whereas the parent crude oil exhibits a high abundant desorption phase. At roughly 330 °C, pyrolysis begins and mass loss as well as complex mass spectrometric patterns were recorded. The resulting information on the effluent gained by the different soft ionization mass spectrometric approaches was combined with the GC–EI–MS data for structural cross-evaluation. We showed that the combination of the applied techniques leads to a more comprehensive chemical characterization. For the asphaltene, TG SPI TOF–MS shows high abundances of alkanes, alkenes, and hydrogen sulfide during pyrolysis. TG REMPI TOF–MS is selective toward aromatics and reveals clear patterns of polyaromatic hydrocarbons (PAHs) and minor amounts of nitrogen-containing aromatics tentatively identified as acridine- or carbazol-like structures. GC–EI–MS provides information on the average chain length of alkanes, alkenes, and PA(S)H. Both atmospheric pressure ionization techniques (APPI and APCI) hyphenated to FT–MS showed CHS (in particular, benzothiophenes) and CH as dominant compound classes, with an average number of condensed aromatic rings of 2–4. Combining the information of all techniques, including the average asphaltene mass obtained by field desorption experiments and aromatic core size received by collision-induced dissociation, the archipelago-type molecular structure seems to be dominant for the investigated asphaltene.

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Section: Introductionmentioning

confidence: 99%

Combination of Different Thermal Analysis Methods Coupled to Mass Spectrometry for the Analysis of Asphaltenes and Their Parent Crude Oils: Comprehensive Characterization of the Molecular Pyrolysis Pattern

et al. 2017

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“…The TGA/mass spectrometer system used in these studies consists of a Perkin-Elmer TGS-2 thermogravimetric analyzer and a Sciex TAGA 6000 MS/MS tandem triple quadrapole mass spectrometer [16]. One to two milligram samples, sealed in a hermetic DSC pan with pinhole to suppress evaporation, were heated at 10~ min -i un-der a 100 ml min -~ air purge.…”

Section: Tga/apci-msmentioning

confidence: 99%

“…Standard thermal analytical techniques can be used to compare chromophore stability but other ancillary techniques including electrochemistry and TGA-MS can provide the required additional mechanistic insights. The full sequence and scope of the decomposition process is conveniently evaluated by thermogravimetric analysis coupled with tandem atmospheric pressure chemical ionization mass spectrometry (TGA-APCI/MS/MS) [16]. In this paper the thermal stability of three derivatives of 4-amino-4'-nitroazobenzene are investigated in which the amine donor (R1 =R2) varies from diethyl to di-n-propyl to diphenyl.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the thermal stability of some nonlinear optical chromophores

Prime¹,

Chiou²,

Twieg

1996

Journal of Thermal Analysis

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Optical data storage is poised to benefit from a new class of advanced polymeric materials engineered I~o exhibit photorefraetivity. Likewise, the transmission and processing of data will also benefit from a related class of materials with electro-optic activity. Organic chromophores are critical constituents of these materials which function due to a change of index of refraction in response to an electric field. However, a number of materials and processing problems remain to be solved before devices incorporating these optically nonlinear ehromophores are practical. For example, for eleetrooptieal applications the NLO waveguide should be able to withstand short duration processing temperatures in excess of 300~ and long duration use temperatures of at least 80~ The requirement for thermoehemical stability follows from the need to implement high T~ matrices to provide stability of the orientational or polar order required for long-term device performance and reliability. As a result, the thermal stability of ehromophores is now more closely evaluated in addition to their transparency and optical nonlinearity properties. Some ehromophore classes, such as the azo dyes studied here, have attractive properties for these applications but further enhancements in overall properties are needed. Identification of the fundamental chemical processes in thermal decomposition of these dyes should lead to introduction of structural changes which provide better stability. Here thermogravimetric analysis (TGA) coupled with mass spectrometry (TGA/MS) is used to provide an assay of thermoehemieal stability with an added benefit that insight into the mechanisms of thermal decomposition may by identified. In this initial study diaryl substitution of the amine in derivatives of 4-amino-4'-nitroazobenzene was observed to greatly enhance thermal stability relative to dialkyl substitution. Substitution of phenyl for alkyl eliminates structural features involved in the most facile degradation mechanism available to the alkyl derivative.

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“…Since the nucleation and growth process is nonlinear with time it is not possible to relate a measured amount of condensed products to an outgassing rate of a resist during exposure. Finally, the API-MS method, 8 while excellent for analyzing mixtures since no fragmentation occurs during ionization, is blind to certain chemical species 9 and is most suited to analysis of a stream of products rather than short bursts as are expected during laser exposure. It requires authentic samples of all products to be made fully quantitative, which is often not possible, although semiquantitative comparison of analyte signals is possible.…”

Section: Introductionmentioning

confidence: 99%

Direct determination of photoresist composition changes during UV exposure

et al. 2006

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Exposure of photoresists to ultraviolet light results in outgassing of species that have the potential to contaminate surrounding optical surfaces. Of particular concern are silicon-containing products which cannot be cleaned and permanently detune optical coatings. Collection and identification of those species and quantification of the amounts formed is a difficult analytical problem because of the number and variety of products. We describe a general methodology for determining acidolytic decomposition pathways and absolute elemental composition changes induced in photoresists during exposure. Two silicon-containing 193 nm resists that differ in the mode of attachment of trimethylsilyl to the polymer have been investigated. Elemental abundances are measured in post-apply baked, exposed and post-expose baked films by secondary ion mass spectrometry (SIMS), thus probing volatile product formation from all photochemical and thermal decomposition pathways. Complementary data on primary thermal acidolytic deprotection pathways during post-exposure bake are obtained by mass spectrometry, enabling SIMS elemental abundance changes to be interpreted. The results show that decomposition of both the polymer protecting groups through room temperature acidolysis and the photoacid generator by photolysis lead to volatile product formation during exposure. Silicon bound through oxygen is acid labile while silicon bound through carbon is not, resulting in very low to no silicon outgassing from the latter polymer. Sulfur-containing products formed from PAGs outgas in significant amounts from the photoresists investigated, supporting recent mass spectrometric observations of sulfur outgassing by R. Kunz and coworkers.

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Thermogravimetric analyzer/atmospheric pressure chemical ionization tandem triple quadrupole mass spectrometer system for evolved gas analysis

Cited by 26 publications

References 22 publications

Combination of Different Thermal Analysis Methods Coupled to Mass Spectrometry for the Analysis of Asphaltenes and Their Parent Crude Oils: Comprehensive Characterization of the Molecular Pyrolysis Pattern

Combination of Different Thermal Analysis Methods Coupled to Mass Spectrometry for the Analysis of Asphaltenes and Their Parent Crude Oils: Comprehensive Characterization of the Molecular Pyrolysis Pattern

Evaluation of the thermal stability of some nonlinear optical chromophores

Direct determination of photoresist composition changes during UV exposure

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