DETERMINATION OF HYDROPEROXIDES IN LIQUID FUELS: A SYSTEMATIC COMPARISON OF TITRATIONS AND ABSORPTION METHODS AND THEIR COUPLING TO HPLC - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2022

DETERMINATION OF HYDROPEROXIDES IN LIQUID FUELS: A SYSTEMATIC COMPARISON OF TITRATIONS AND ABSORPTION METHODS AND THEIR COUPLING TO HPLC

Résumé

Hydroperoxides are major products in the autoxidation of fuels and play a central role in oxidation kinetics. Their presence affects the oxidation rate, even at low concentrations, and, in turn, the thermal stability of fuels. Standard techniques for the quantification of hydroperoxides (ROOH) in fuel involve the reduction of ROOH by I$^-$, yielding iodine (I$_2$), which can be quantified by titration. These ASTM methods are known to have poor reproducibility, inadequate lower detection limits and limited dynamic ranges. In this work, several analytical methods for the quantification of hydroperoxides in surrogate fuels have been systematically compared for a known concentration of ROOH: titration of iodine with thiosulfate (ASTM D3703) or triphenylphosphine (TPP) solutions with colorimetric and potentiometric methods and quantification of iodine by UV-visible absorption. n-Decane was used as the surrogate fuel and tert-butyl hydroperoxide as the controlled ROOH content. Our systematic study shows that the ASTM method based on colorimetric titration using thiosulfate in aqueous solution is the least accurate because of the non-miscibility of water and n-decane, which even makes the UV-visible spectroscopy method ineffective. The other titration method in the literature, using TPP dissolved in n-decane as the titrant does not have any miscibility problem. Potentiometric titration is found to be more reproducible and accurate than colorimetric titration. The UV-visible absorption method allows reaching lower detection limits. We show that the combination of the potentiometric titration of iodine with TPP and UV-visible absorption allows for determining ROOH concentrations with low detection limits and a large dynamic range. The advantages of both methods have been used to develop a new analytical method based on their coupling in HPLC.
Fichier principal
Vignette du fichier
IASH 2022_final_Benrabah_vf.pdf (615.15 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-04561117 , version 1 (26-04-2024)

Identifiants

  • HAL Id : hal-04561117 , version 1

Citer

Ryma Benrabah, Zaki El Sayah, Pierre-Alexandre Glaude, Philippe Arnoux, Baptiste Sirjean. DETERMINATION OF HYDROPEROXIDES IN LIQUID FUELS: A SYSTEMATIC COMPARISON OF TITRATIONS AND ABSORPTION METHODS AND THEIR COUPLING TO HPLC. 17TH INTERNATIONAL CONFERENCE ON STABILITY, HANDLING AND USE OF LIQUID FUELS, IASH, Sep 2022, DRESDE, Germany. pp.153-167. ⟨hal-04561117⟩
0 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More