Accueil
Détail de l'auteur
Auteur Francina Izquierdo
Commentaire :
Asociacion Quimica Espanola de la Industria del Cuero - Igualada - Spain
|
Documents disponibles écrits par cet auteur
Ajouter le résultat dans votre panier Affiner la recherche
Comparison of the inhibition efficiency of natural and synthetic phenolic antioxidants on Cr(VI) formation / Alper Kilikli in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 3 (03/2017)
[article]
Titre : Comparison of the inhibition efficiency of natural and synthetic phenolic antioxidants on Cr(VI) formation Type de document : texte imprimé Auteurs : Alper Kilikli, Auteur ; Francina Izquierdo, Auteur ; Ivo Reetz, Auteur Année de publication : 2017 Article en page(s) : p. 81-87 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Antioxydants
Chrome hexavalent
Emulsions
Essais (technologie)
Huiles et graisses de poissons
Oxydation
Phénoliques, AcidesUn acide-phénol (ou acide phénolique) est un composé organique possédant au moins une fonction carboxylique et un hydroxyle phénolique. La pratique courante en phytochimie consiste à réserver ce terme aux dérivés de l’acide benzoïque et de l’acide cinnamique.
Les acides hydroxybenzoïques dérivent par hydroxylation de l’acide benzoïque avec une structure de base de type C6-C1. Ces hydroxyles phénoliques OH peuvent ensuite être méthylés.
Exemples : l'acide gallique, élément constitutif des tanins hydroxylables et l'acide vanillique dont l'aldéhyde, la vanilline, est bien connue comme l'arôme naturel de vanille.
Les dérivés de l'acide cinnamique, les acides hydroxycinnamiques ont une structure de base de type C6-C3. Ils appartiennent à la grande famille des phénylpropanoïdes. Les hydroxyles phénoliques OH de ces dérivés peuvent aussi être méthylés (-O-CH3).
Exemples : l'acide paracoumarique, dont les lactones, les coumarines, sont largement distribuées dans tout le règne végétal, l'acide caféique, très large représentation chez les végétaux, souvent sous forme de l'acide chlorogénique (ester avec l'acide quinique), comme dans le grain de café, la pomme ou sous forme d'acide 1,3-dicaféylquinique (cynarine) dans l'artichaut et d'acide rosmarinique dans le romarin et le thé de Java (orthosiphon), l'acide férulique et l'acide sinapique.
Dans les plantes, ces acides-phénols sont souvent sous forme d'esters d'alcools aliphatiques ou d'esters de l'acide quinique, de l'acide rosmarinique ou de glycosides.
Phénols
Tara et constituantsC'est un petit arbre épineux avec des gousses plates rouge qui pousse dans les zones sèches du Pérou, Amérique du Sud.Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Gallic acid, gallic acid esters with various chain lengths, tara and tara hydrolysates are compared with one commercially successful synthetic phenolic antioxidant in various protocols for antioxidant testing, and regarding their capability to reduce the proneness to Cr(VI) formation in leather. The results are discussed in light of the Polar Paradox Theory and the possible interaction of the antioxidants with components in the leather matrix. The aim of these investigations is an optimum prevention of Cr(VI) formation in leather. Note de contenu : - EXPERIMENTAL : Materials - Methods : Hydrolyzation of tara - Total phenolic - Hydrolysis degree - 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging measurements - Oxidation experiments in fish oil and fish oil emulsions - Results of antioxidant trials - Leather trial - Cr(VI) measurement in leather - Heat yellowing - Phenolic content - DPPH radical scavening - Assessment of reduction of Cr(VI) formation in leather En ligne : https://drive.google.com/file/d/1lcmZPHDOg4rflxD4EE8fpqYdB0NNtlJt/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27979
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 3 (03/2017) . - p. 81-87[article]Réservation
Réserver ce documentDetermination of formaldehyde content in leather : standard EN ISO 17226 (parts 1 and 2), revision and possible improvements / Sara Cuadros in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 100, N° 4 (07-08/2016)
[article]
Titre : Determination of formaldehyde content in leather : standard EN ISO 17226 (parts 1 and 2), revision and possible improvements Type de document : texte imprimé Auteurs : Sara Cuadros, Auteur ; Joaquim Font, Auteur ; Francina Izquierdo, Auteur ; Rosa M. Cuadros, Auteur ; Lluis Ollé, Auteur ; Agusti Marsal, Auteur Année de publication : 2016 Article en page(s) : p. 167-174 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuir -- Teneur en formaldéhyde
Cuirs et peaux -- Analyse
Extraction (chimie)
Normalisation
SurfactantsIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : The retanning process is the main application of formaldehyde in the tanning industry since formaldehyde participates in two groups of synthetic organic tanning agents: syntans and resins. Resins can be hydrolysed with the result that formaldehyde is released. Thus, formaldehyde in leather can be free or from hydrolysis of resins. Due to the carcinogenic character of formaldehyde, its presence in leather should be avoided or should be below allowable limits. The EN ISO 17226 Standard is the Official Standard for the determination of formaldehyde content in leather, which, in the authors' opinion, presents certain ambiguities in the wording of some operations included in their analysis methods and, some of these operations, are susceptible of improvement. Therefore, a revision of the EN ISO 17226 Standard (Parts 1 and 2) is carried out in this work and, in particular, of the extraction phase of formaldehyde present in leather (possible use of alternative surfactant and shaking method) ; reaction time between the extracted formaldehyde with the dinitrophenyihydrazine solution (Part 1 of the Standard) and stability of the acetylacetone solution (Part 2 of the Standard). Note de contenu : - AIM OF THE WORK
- MATERIALS AND METHODS : Starting material. Formulation applied - Methods. Determination of formaldehyde in leather
- EXPERIMENTAL PROCEDURES : Revision of the EN ISO 17226 standard
- TABLES : 1. Current limits for formaldehyde in differents countries - 2. Current limits for formaldehyde in accordance with the "Restricted Substances Lists" (RSL) of major brands - 3. General formulations for different treatments carried out - 4. Formaldehyde content in samples extracted with sodium dodecyl sulphate or sodium dodecyl sulphonate for different retanning treatments. Quantification of formaldehyde by HPLC - 5. Formaldehyde content iin samples extracted with sodium dodecyl sulphate or sodium dodecyl sulphonate for different retanning treatments. Quantification of formaldehyde by colourimetry - 6. Formaldehyde content in samples using magnetic agitation or reciprocal linear agitation in the extraction phase for different retanning treatments (ISO 17226:2) - 7. Formaldehyde content in samples using fresh or aged acetylacetone solution for different retanning treatments. Quantification by colourimetryEn ligne : https://drive.google.com/file/d/1kN8neLZ3EgiEoFOJj3irrOLrLrHhCFiD/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=26793
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 100, N° 4 (07-08/2016) . - p. 167-174[article]Réservation
Réserver ce documentEcological fatliquoring - fish or veg ? / Francina Izquierdo in LEATHER INTERNATIONAL, Vol. 214, N° 4819 (04/2012)
[article]
Titre : Ecological fatliquoring - fish or veg ? Type de document : texte imprimé Auteurs : Francina Izquierdo, Auteur Année de publication : 2012 Article en page(s) : p. 34-36 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Conservation
Durée de vie (Ingénierie)
Environnement -- Etudes d'impact
Huiles et graisses de poissons
Huiles et graisses végétales
Produits de conservation du cuirIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Fatliquors for leather are usually very complex products. The major part of a natural based leather fatliquor consists of processed natural oils or substances derived from them. Furthermore, there can be emulsifiers, crude oils, antioxidants and various auxiliaries improving the penetration of the lubricating components and/or the stability of the formulation.
Fish oil has for many decades been the most prominent raw material used for leather fatliquors. The main advantage of fish oil in application is the high level of softness it creates in leather. By means of sulphitationor sulphation, fish oil can easily be transformed into the anionic, lubricating material which effectively prevents the leather fibres from sticking together.
With the premise to produce eco-friendly leather articles, one has to ask, how sustainable is the use of fish oil in comparison with its most important alternative, vegetable oils ? This paper provides an overview of the sustainability of both oils and the advantages of replacing fish oil with alternatives that have a better eco-profile.Note de contenu : - Sustainability of fish oil versus vegetable oils
- Ecological impact
- Life cycle
- Leather propertiesEn ligne : https://drive.google.com/file/d/1OHT1rk80w3nA8Bfj5svXBmh5fD2zsWzH/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=14710
in LEATHER INTERNATIONAL > Vol. 214, N° 4819 (04/2012) . - p. 34-36[article]Réservation
Réserver ce documentA simple test to determine the propensity of a fatliquor to trigger the formation of chromium (VI) in leather / Irene Compte in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 11 (11/2022)
[article]
Titre : A simple test to determine the propensity of a fatliquor to trigger the formation of chromium (VI) in leather Type de document : texte imprimé Auteurs : Irene Compte, Auteur ; Rosa M. Cuadros, Auteur ; Francina Izquierdo, Auteur ; Felipe Combalia, Auteur ; Anna Bacardit, Auteur Année de publication : 2022 Article en page(s) : p. 480-488 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chimie analytique
Chrome hexavalent
Chrome trivalent -- Oxydation
Liqueurs de tannageIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Since the entry into force of the EU Commission Regulation regarding hexavalent chromium in leather articles in 2014, it is of paramount importance to follow good manufacturing practices to ensure the production of leather not only free of Cr(VI) but with no tendency to its formation. The equilibrium between Cr(III) and Cr(VI) in leather can be disturbed under stressful environmental conditions such as light or heat exposure. These factors could trigger the lipid peroxidation of unprotected unsaturated fatliquoring agents, thus leading to the oxidation of Cr(III) to Cr(VI). Due to the relevance that the oxidation of the fatliquoring agents has in the subsequent Cr(VI) formation, the Propensity Test has been developed and verified as an innovative verifying in-house tool for tanners to verify that each of the fatliquoring agents used in the tannery processes are properly protected against oxidation and thus, that Cr(VI) formation is not triggered.The method has four simple steps and can be easily carried out in the tanneries’ pilot plant. It does not require special equipment or specific apparatus because all the necessary instruments are usually available in any tannery and the skills needed to perform the test are the same that leather technicians use in their day-to-day work, so the implementation cost is practically non-existent.This work leads to the conclusion that there is a higher possibility of Cr(VI) formation among sheep skins rather than among calf hides. The rechroming process also presents risks regarding Cr(VI) content in leather, however, in this study it has been shown that rechroming does not increase Cr(VI) formation risks when the fatliquoring agents are properly protected against autoxidation. Therefore, using a well-protected fatliquoring agent is mandatory for the purpose of producing Cr(VI)-free leather despite the type of leather. Note de contenu : - INTRODUCTION : Influence of faliquoring in Cr(VI) formation - Testing for Cr(VI)-free raw materials
- EXPERIMENTAL : Skins and hides - Materials and facilities - Propensity test recipe - Testing for hexavalent chromium - Apparent density of leather
- RESULTS AND DISCUSSION : Performance of the propensity test - Validation of thepropensity test - Cr(VI) content depending on the type of leather - Influence of the rechroming process
- Table 1 : Recipe to test a fatliquoring agent for propensity to the formation of hexvalent chromium
- Table 2 : Fatliquors tested during the development of the propensity test
- Table 3 : Cr(VI) content in mg/kg of the experiments for the developing of the propensity test
- Table 4 : Apparent density of the fatliquored leathers.
- Table 5 : Comparison of the Cr(VI) content in mg/kg of the rechrçmed and not-rechromed leathersDOI : https://doi.org/10.34314/jalca.v117i11.6294 En ligne : https://drive.google.com/file/d/1JTGfnNwD0pUvNwz6m4yhvoUoLEx2yOPA/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38341
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 11 (11/2022) . - p. 480-488[article]Réservation
Réserver ce documentA simple test to determine the propensity of a sample of leather to the formation of chromium / Joaquim Font in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 2 (02/2018)
[article]
Titre : A simple test to determine the propensity of a sample of leather to the formation of chromium Type de document : texte imprimé Auteurs : Joaquim Font, Auteur ; Marta Bacardit, Auteur ; Niria Pascual ; Rosa M. Cuadros ; Francina Izquierdo Année de publication : 2018 Article en page(s) : p. 65-71 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse quantitative (chimie)
Colorimétrie
Cuir -- Teneur en chrome hexavalent
Cuirs et peaux -- Analyse
Décoloration
Extraction par solvant
PyrolyseLa pyrolyse est la décomposition ou thermolyse d'un composé organique par la chaleur pour obtenir d'autres produits (gaz et matière) qu'il ne contenait pas. L'opération est réalisée en l'absence d'oxygène ou en atmosphère pauvre en oxygène pour éviter l'oxydation et la combustion (L’opération ne produit donc pas de flamme). Il s'agit du premier stade de transformation thermique après la déshydratation.
Elle permet généralement d'obtenir un solide carboné, une huile et un gaz. Elle débute à un niveau de température relativement bas (à partir de 200 °C) et se poursuit jusqu'à 1 000 °C environ. Selon la température, la proportion des trois composés résultants est différente.Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Since the EU Commission Regulation of chromium(VI) in leather articles, there is a huge demand of analyses and controls in the leather sector for this parameter.
However, for many tanners and leather dealers, the necessary cost to have a laboratory capable to carry out the analyses according to an ISO method is not affordable.
An easy test has been developed to carry out a screening of a leather sample in order to check out its compliance with the Cr(VI) restriction. This test is able to distinguish leathers that contain chromium(VI) or show signs of tendency to develop it, from leathers that even after thermal ageing exposure remain free of it.
The test is based on the scientist principle of the ISO 17075-1 method. Some operations of this Standard have been adapted with the aim of saving costs and simplifying and shortening the workload of the test. The essential criterion of this adaptation has been that the developed test does not lead to false negatives.
The only required devices are a laboratory oven, a balance of 0.01g of resolution, and a shaker. Neither a spectrophotometer nor a colorimeter is necessary.
The method has four main steps. The first one is an ageing process at 80°C during 24 hours. After cooling down for 30 minutes, the sample is extracted for one hour, using an overhead rotatory shaker or a magnetic stirrer. The third step is the discoloration of the extract, to remove the dyes of the colored solution so as to eliminate interferences. Finally, the extract is assessed by visual colorimetry. The workload per sample is about 40 minutes.
So far, more than 300 samples of leather have been tested. The kit performed very well and only gave 5% of false positives. The kit did not commit any false negative.Note de contenu : - MATERIALS AND METHODS : Samples - Reagents and instruments for the LeatherKit_Cr6 method - Instruments for the ISO 17075-2 reference method - Operating procedure for LeatherKit_Cr6 method - Measurement
- RESULTS AND DISCUSSION : Ageing - Cooling down time - Degasification of samples and extration solution - Extraction procedure - Color removal - DeterminationEn ligne : https://drive.google.com/file/d/1-Pc0JEd9a6YcAPhK0_-PJAntrsYBnDj0/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29955
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 2 (02/2018) . - p. 65-71[article]Réservation
Réserver ce documentUse of long-chain synthetic phenolic antioxidants to produce chromium-tanned leather without risk of hexavalent chromium formation / Irene Compte in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVIII, N° 10 (10/2023)
Permalink