A simple criterion for gas chromatography/mass spectrometric analysis of thermally unstable compounds, and reassessment of the by‐products of alkyl diazoacetate synthesis

Kornilova, T. A.; Ukolov, A. I.; Kostikov, R. R.; Зенкевич, И. Г.

doi:10.1002/rcm.6457

Cited by 17 publications

(9 citation statements)

References 13 publications

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“…The GC method was established by the referring literatures. 41,42 In detail, the column was an INNOWAX column (length, 30 m; ID, 0.25 mm; film thickness, 0.25 μm); the oven temperature was kept at 318 K for 2 min, increased to 338 K by 5 K/min, kept at 338 K for 5 min, increased to 623 K by 50 K/min, and then held for 15 min; the flow rate of nitrogen as the carrier gas was 40 mL/min with a split ratio of 1:200; and the injector temperature was 373 K.…”

Section: Methodsmentioning

confidence: 99%

Thermal Decomposition of Ethyl Diazoacetate in Microtube Reactor: A Kinetics Study

Xin

2018

ACS Omega

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Ethyl diazoacetate (EDA) commonly experiences intensive decomposition as well as complex conversion concerning safety and efficiency. In this work, a careful kinetics study on the thermal decomposition of EDA was isothermally conducted in a microtube reactor to establish a mechanism-based kinetic model. The model parameters were well calibrated with experimental data including the yield of dimmers and the conversion of EDA, confirming the rationality of the proposed three-step reaction route. It allows the model to concisely describe the complex species transformations during EDA decomposition, which is unavailable for an apparent kinetic model. Considering an isothermal reaction system and the tolerance of EDA consumption by thermal decomposition, this work could help reveal the requirement on the kinetic characteristics of the desired catalytic reaction in which EDA is involved, as a reference on reaction process modeling and regulation.

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Section: Methodsmentioning

confidence: 99%

Thermal Decomposition of Ethyl Diazoacetate in Microtube Reactor: A Kinetics Study

Xin

2018

ACS Omega

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“…Just these relationships confirm that analytes' decomposition in GC column seem to be difficult to eliminate, because if we decrease the column's temperature, we increase the analyte's residence time in the heated area. Besides the examples listed above, the decomposition inside GC column (in addition to decomposition in an injector) is valuable for diazocarbonyl compounds, decomposed with the formation of substituted ketene in the result of so-called Wolff rearrangement [13]:…”

Section: Different Kinds Of Analytes' Instability Complicating Gas Chmentioning

confidence: 99%

“…It is interesting to note that resulted ketenes are unstable compounds as well; they cannot be isolated as individual substances or components of concentrated solutions due to easy polymerization, and, hence, do not form distinct chromatographic peaks. In the result, their mass spectra were registered successfully [13], but GC RIs cannot be determined excepting the most volatile simplest member of this series -dimethyl ketene (RI non-polar 484, RI polar 1215 [2]).…”

Section: Different Kinds Of Analytes' Instability Complicating Gas Chmentioning

confidence: 99%

“…Some examples of such distortions are presented on Figures below. For example, decomposition of 1-diazo-4-phenylbutan-2-one, C 6 H 5 CH 2 CH 2 COCH=N 2 within a column leads to the formation of "train" (Z) of ketene C 6 H 5 CH 2 CH 2 CH=C=O prior the peak of initial diazocompound, but this ketene does not form a separate chromatographic peak [13].…”

Section: The Influence Of the Decomposition Of Analytes In Chromatogrmentioning

confidence: 99%

“…T lim ≈ 140°C. The applicability of this criterion has been verified during analysis of aryl substituted diazocarbonyl compounds [13]. For instance, such analyte as 1-diazo-4-phenylbuten-2-one, C 6 H 5 CH 2 CH 2 COCHN 2 , was analyzed under conditions ensuring its retention temperature 145°C, slightly exceeding T lim ≈ 140°C.…”

Section: Criterion Of Applicability Of Gc / Gc-ms Analysis For Thermamentioning

confidence: 99%

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Features and New Examples of Gas Chromatographic Separation of Thermally Unstable Analytes

Зенкевич¹

2022

Recent Advances in Gas Chromatography

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The processes of thermal decomposition of analytes in gas chromatographic (GC) columns are classified and two new examples of them are considered in details. First of them is monomolecular decomposition of monoalkyl esters of benzene-1, 2-dicarboxylic (phthalic) acid (monoalkyl phthalates). This process has the analogy in chemical reactions in solutions and it may be responsible for the toxicity of phthalates. The second example is decomposition of non-substituted hydrazones of both aliphatic and aromatic carbonyl compounds. The analytes of the second sub-group present the first example of bimolecular (second order) decomposition in a GC column: two molecules of hydrazones form stable azines and hydrazine. Besides that this process presents the particular interest, because it is accompanied by secondary chemical reactions not in an injector, but within GC column, when a by-product of decomposition is involved into secondary interaction with other constituents of the samples. It was confirmed, that visual images of all these decomposition processes on the chromatograms are rather identical and coincide with the manifestations of interconversion of isomers or tautomers. The most often expressed features of chromatographic profiles in such cases are the presence of peaks of an initial analyte and a product of its decomposition or isomerization, connected with more or less expressed diffused “plateau” or “train” between them. The decomposition processes during sample preparation prior to chromatographic separation or in the heated injector of GC instrument are not accompanied by such features. Despite of the rather “exotic” character of the examples considered, the knowledge of them seems to be useful for better revealing the analogous situations in chromatographic practice. Thermal instability of analytes is the principal restriction of GC separation of reactive compounds and we cannot eliminate it for objective reasons. However, in some cases we can evaluate the temperature limits of chromatographic columns, which should not be exceeded during GC separation of instable compounds. The simplest (low boiling) homologs of thermally unstable compounds are often characterized by “normal” boiling point at atmospheric pressure (T b, °C) without decomposition, that means the possibility of their GC analysis unambiguously. Therefore, we can select such T b values as GC and/or GC–MS temperature limit (T lim) for other members of series of thermally unstable homologs. If GC separation is carried out not in isothermal, but in temperature programming conditions, so-called retention temperature (T R) of unstable analytes should not exceed the evaluated T lim value.

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Secondary electrospray ionization-high resolution mass spectrometry (SESI-HRMS) fingerprinting enabled treatment monitoring of pulmonary carcinoma cells in real time

Choueiry

Zhu

2022

Analytica Chimica Acta

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A simple criterion for gas chromatography/mass spectrometric analysis of thermally unstable compounds, and reassessment of the by‐products of alkyl diazoacetate synthesis

Cited by 17 publications

References 13 publications

Thermal Decomposition of Ethyl Diazoacetate in Microtube Reactor: A Kinetics Study

Thermal Decomposition of Ethyl Diazoacetate in Microtube Reactor: A Kinetics Study

Features and New Examples of Gas Chromatographic Separation of Thermally Unstable Analytes

Secondary electrospray ionization-high resolution mass spectrometry (SESI-HRMS) fingerprinting enabled treatment monitoring of pulmonary carcinoma cells in real time

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