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Tesi etd-06222015-143807


Thesis type
Tesi di laurea magistrale
Author
FERRARO, DAMIANO
URN
etd-06222015-143807
Title
Derivatization of carboxylic acids in biological matrices with triethyloxonium tetrafluoroborate and their determination by gas chromatography mass spectrometry
Struttura
CHIMICA E CHIMICA INDUSTRIALE
Corso di studi
CHIMICA
Commissione
relatore Prof. D'Ulivo, Alessandro
controrelatore Prof. Di Francesco, Fabio
relatore Prof.ssa Giannarelli, Stefania
Parole chiave
  • salicylic acid
  • propionic acid
  • perfluorooctanoic acid
  • hexanoic acid
  • butyric acid
  • GC-MS
  • triethyloxonium salt
  • benzoic acid
  • indole-3-acetic acid
  • Liquid–liquid extraction
Data inizio appello
16/07/2015;
Consultabilità
parziale
Data di rilascio
16/07/2018
Riassunto analitico
In this work of thesis we propose the derivatization with triethyloxonium tetrafluoroborate for the quantitation of several organic acids of biological relevance (indole-3-acetic acid, benzoic acid, salicylic acid, propionic acid, butyric acid and perfluorooctanoic acid). The accurate determination of these molecules is mandatory a) to understand the metabolic processes crucial for plant growth and development (indole-3-acetic acid, benzoic acid, salicylic acid); b) to determine analytes indicators of bacterial activity and of interest in nutrition, bacteriological and environmental studies (salicylic acid, propionic acid, butyric acid)[2]; to measure drugs metabolites after their administration (e.g. salicylic acid from aspirin)[3] d) to quantify environmental pollutants associated with adverse health effects (perfluorooctanoic acid)[4].
The aforementioned carboxylic acids were simultaneously extracted in slightly alkaline solution and ethylated with triethyloxonium tetrafluoroborate from various matrices (Nicotiana tabacum and Actinidia deliciosa leaves, urine and saliva from healthy volunteers). Compared to the common derivatization approaches for GC analysis, the proposed method is simple and offers a fast sample preparation, involving only centrifugation, derivatization and extraction of the resulting ethyl-ester with methyl tert-butyl ether.
We optimized some effective parameters of the derivatization step, such as pH of reaction medium, the amount of derivatization reagent, derivatization and extraction time. The ethyl esters were determined by gas chromatography–mass spectrometry (GC–MS), using the respective deuterated acids as internal standards. The method was validated in terms of linearity, repeatability, recovery, limit of detection and limit of quantitation, evaluation of matrix effect.
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