Profiling of organic acids by capillary gas chromatography–mass spectrometry after direct methylation in urine using trimethyloxonium tetrafluoroborate

Liebich, H.M.; Gesele, Elke

doi:10.1016/s0021-9673(99)00416-1

Cited by 25 publications

(14 citation statements)

References 16 publications

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“…In the past diazomethane was considered the most effective methylating agent, but because of its well-known extreme toxicity, high irritatance and explosivity, studies on methods for its replacement have been reported. The methylester derivatives of the acids were synthesized, as indicated in the literature (Liebich et al, 1999). Briefly, 2 mL of water containing each of the seven substances were treated as indicated above, extracted with 0.5 mL of chloroform and analyzed using a GC-MS detector.…”

Section: Resultsmentioning

confidence: 99%

“…Urine Control Levels 1 and 2 (ClinChek Recipe) were purchased from VWR International (Milan, Italy). The methylester derivatives of the acids were synthesized by the authors as indicated in the literature (Liebich et al, 1999), except for SA methylester, which was purchased from Tokyo Kasei Organic Chemicals (Prodotti Gianni, Milan, Italy).…”

Section: Methodsmentioning

confidence: 99%

“…These methods employ a sample derivatization technique to convert such polar substances into hydrophobic compounds whose volatility is sufficiently high for a GC determination. (Liebich et al, 1998;Liebich and Gesele, 1999;Sonntag et al, 2004). The applications of trimethyloxonium tetrafluoroborate as a methylating agent were implemented in this work.…”

Section: Introductionmentioning

confidence: 99%

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Determination of organic acids in urine by solid‐phase microextraction and gas chromatography–ion trap tandem mass spectrometry previous ‘in sample’ derivatization with trimethyloxonium tetrafluoroborate

Pacenti

Dugheri

Villanelli

et al. 2008

Biomedical Chromatography

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A method for the determination of the organic acids directly in the urine employing derivatization with trimethyloxonium tetrafluoroborate as a methylating agent and sequential extraction by head space and direct immersion/solid phase microextraction is reported. Furoic acid, hippuric acid, methylhippuric acid, mandelic acid, phenylglyoxylic acid and trans, trans muconic acid contained in urine and proposed by the American Conference of Governmental Industrial Hygienists as biological exposure indices were determined after a fast and economically convenient preparation step and sensitive gas chromatography-ion trap-mass spectrometry/tandem mass spectrometry analysis. Urine is rather a complex sample and hence the acquisition method required specific GC-MS instrumentation capable of supporting the changeover, fully automated during a single chromatographic separation, from mass to tandem mass spectrometry and both chemical and electron ionization modes. The automation of the analytical method provides a number of advantages, including reduced analysis time for both routine analysis and method development, and greater reproducibility. The equilibrium and kinetics of this substances vs head space/direct immersion-solid phase microextraction were investigated and evaluated theoretically.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Determination of organic acids in urine by solid‐phase microextraction and gas chromatography–ion trap tandem mass spectrometry previous ‘in sample’ derivatization with trimethyloxonium tetrafluoroborate

Pacenti

Dugheri

Villanelli

et al. 2008

Biomedical Chromatography

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“…Trialkyloxonium ions (Meerwein salts), R3O+, with various counterions such as SbF6−, BF4−, SbCl6−, and PF6−are excellent alkylating agents for nucleophiles containing heteroatoms such as N, O, or S [32]. With TMO a methyl group of the oxonium ion reacts with the anion of the a -OH functional group to form the methyl ether.…”

Section: Figure 2 Gc Chromatogram and Ei-ms Spectrum Of The Three Stmentioning

confidence: 99%

Polymerization Inhibitors and Promoters for Unsaturated Polyester Resins; Use of Solid Phase MicroExtraction and Gas Chromatography Coupled to Mass Spectrometry for the Determination of 4-tert-Butyl Catechol and Acetylacetone

Dugheri¹,

Gentili²,

Bonari³

et al. 2017

Eurasian J Anal Chem

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This paper reports a contribution of three on-sample derivatization sampling techniques for acetylacetone, 4-tert-butyl catechol and its oxidated derivatives 4-tert-butyl-1,2-benzoquinone determination in unsaturated polyester resins. The use of O- (2,3,4,5,6, pentafluorobenzyl)-hydroxylamine, trimethyloxonium tetrafluoroborate and O-methylhydroxylamine is combined with automated head space/solid phase microextraction and gas chromatography/mass spectrometry analysis. For an innovative powerful meaning in high-throughput routine, the generality of the structurally informative mass spectrometry fragmentation patterns together with the chromatographic separation are also investigated. The detection limits for these polymerization inhibitors and promoters are less than 27 pg for one mg of unsaturated polyester resin. In this study a new autosampler platform is proposed by using the Multi Fiber Exchange device in a xyz robotic system. We promote these methods as the analytical reference in the polyester resin field. The introduction of dedicated, automated, and robotic systems allowed a friendly use of MS apparatus for high-throughput screening and it reduces the costs of monitoring campaigns.

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“…For the analysis of organic acids by GC, a prior derivatization step is necessary because of their high polarity and poor chromatographic properties. After an extraction step, the derivatization of organic acids to short-chain esters using different reagents, such as BF 3 -methanol [15], trimethyloxonium tetrafluoroborate [16], or pentafluorobenzyl bromide [7,15,17], is often applied. In general, the derivatization is performed either under dry conditions or by evaporation of the matrix sample.…”

Section: Introductionmentioning

confidence: 99%

Determination of methylmalonic acid and glutaric acid in urine by aqueous‐phase derivatization followed by headspace solid‐phase microextraction and gas chromatography‐mass spectrometry

Deng²,

Zhang

2007

J of Separation Science

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In this work, a novel technique of aqueous-phase derivatization followed by headspace solid-phase microextraction and gas chromatography-mass spectrometry was developed for the determination of organic acids in urine. The analytical procedure involves derivatization of organic acids to their ethyl esters with diethyl sulfate, headspace sampling, and GC/MS analysis. The proposed method was applied to the determination of methylmalonic acid and glutaric acid in urine. The experimental parameters and method validation were studied. Optimal conditions were obtained: PDMS fiber, extraction temperature 55 degrees C, extraction time 30 min, and 60 microL of diethyl sulfate as derivatization reagent with 2 mg of the ion pairing agent tetrabutylammonium hydrogensulfate. The method was linear over three orders of magnitude, and detection limits were 21 nM for methylmalonic acid and 34 nM for glutaric acid, respectively. Consequently, in-situ derivatization/HS-SPME/GC/MS is an alternative and powerful method for determination of organic acids as biomarkers in biological fluids.

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Profiling of organic acids by capillary gas chromatography–mass spectrometry after direct methylation in urine using trimethyloxonium tetrafluoroborate

Cited by 25 publications

References 16 publications

Determination of organic acids in urine by solid‐phase microextraction and gas chromatography–ion trap tandem mass spectrometry previous ‘in sample’ derivatization with trimethyloxonium tetrafluoroborate

Determination of organic acids in urine by solid‐phase microextraction and gas chromatography–ion trap tandem mass spectrometry previous ‘in sample’ derivatization with trimethyloxonium tetrafluoroborate

Polymerization Inhibitors and Promoters for Unsaturated Polyester Resins; Use of Solid Phase MicroExtraction and Gas Chromatography Coupled to Mass Spectrometry for the Determination of 4-tert-Butyl Catechol and Acetylacetone

Determination of methylmalonic acid and glutaric acid in urine by aqueous‐phase derivatization followed by headspace solid‐phase microextraction and gas chromatography‐mass spectrometry

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