Determination of hexavalent chromium in leather by ion-exchange chromatography / Joaquim Font in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 98, N° 4 (07-08/2014)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 98, N° 4 (07-08/2014) . - p. 151-157 Titre : Determination of hexavalent chromium in leather by ion-exchange chromatography Type de document : texte imprimé Auteurs : Joaquim Font, Auteur ; Carme Pérez, Auteur ; Maria R. Reyes, Auteur ; Mireia Cobos, Auteur ; Felipe Combalia, Auteur ; Agusti Marsal, Auteur Année de publication : 2014 Article en page(s) : p. 151-157 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chromatographie par échange d'ions Cuir -- Teneur en chrome hexavalent Cuirs et peaux -- Analyse Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The determination of traces of hexavalent chromium in leather and in leather consumer goods is carried out by ion-exchange chromatography. Samples are extracted at pH7.5-8 with a phosphate buffer, according to the method of the current ISO 17075 Standard. The extracts are filtered and analysed by HPLC using an ion-exchange stationary phase and a PDA detector, without any clean up process. An ammonium sulphate electrolyte at pH8 is used as mobile phase. The determination of the recovery yields rates from 84 to 108%. The HPLC method is compared with the current ISO 17075 Standard, which is based in the classical method of the diphenylcarbazide. The data from these results, and from those of recovery rate studies, leads us to conclude that the HPLC method is a better alternative for determining chromium (VI) in leather samples. The new method shortens the procedure of the current ISO 17075 Standard, diminishes workload, reduces the amount of laboratory wastes and its results are much more precise. HPLC is able to measure the chromium (VI) concentration of samples up to 3mg/kg, the detection limit of the current Standard. Note de contenu : - RESULTS AND DISCUSSION : Linearity of the chromatographic method - Selectivity of the chromatographic method - Influence of mobile phase concentration - Time stability of the mobile phase - Limit of detection - ANALYSIS OF LEATHER SAMPLES : Comparison of precision and recovery rate of the results of both methods En ligne : https://drive.google.com/file/d/1u5n2r88RiXLbK1mf0sbelyzG2opknywl/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21814 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
16445	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Determination of hexavalent chromium in leather by ion-exchange chromatography. Direct method versus post-column derivatisation method / Irene Compte in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 105, N° 4 (07-08/2021)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 105, N° 4 (07-08/2021) . - p. 175-182 Titre : Determination of hexavalent chromium in leather by ion-exchange chromatography. Direct method versus post-column derivatisation method Type de document : texte imprimé Auteurs : Irene Compte, Auteur ; Rosa M. Cuadros, Auteur ; Anna Bacardit, Auteur ; Felipe Combalia, Auteur ; Joaquim Font, Auteur Année de publication : 2021 Article en page(s) : p. 175-182 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chromatographie par échange d'ions Chrome hexavalent Cuir -- Teneur en chrome hexavalent Cuirs et peaux -- Analyse Extraction (chimie) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The ISO 17075-2 Standard was published in 2017. In this standard appeared for the first time the determination of hexavalent chromium in leather by liquid chromatography. Two alternative instrumental options are proposed in this method: the direct determination of the absorbance of the chromate peak (Annex B of the Standard) or after the post-column derivatisation with diphenylcarbazide (Annex C). Instrumental performance parameters and economic costs between both methods are compared in this paper. One hundred different leathers were analysed by both chromatographic systems. The two methods proved very good correlation. The post-column method has a higher instrumental sensitivity compared to the direct detection method, which is important to reduce the uncerteinty of the measure in semples around the 3mg/kg current regulatory limit. Other important advantages are its absolute selectivity, which allows the secure identification of the hexavalent chromium in all type of complicated matrixes, and the higher durability of its well protected columns due to the use of cost-effective guard columns. Due to the technical advantages and the slight difference in the equipment cost, which can be compensated thanks to the larger lifespan of the chromatographic columns, it is concluded that the post-column method is the most suitable option for the most determination of hexavalent chromium in leather. Note de contenu : - MATERIALS AND METHODS : Chemicals - Samples - Extraction - RESULTS AND DISCUSSION : Optimisation of the post-column conditions - Method validation - Repeatability and accuracy of the post-column determination method - Analysis of leather samples - Economic assessment - Table 1 : Optimisation of the mobile phase ionic strength - Table 2 : Optimisation of the mobile phase flow - Table 3 : Optimisation of the post-column reagent flow - Table 4 : Comparison of three different cartridges - Table 5 : Concentration of Cr(VI) obtained in 14 leather samples, all of them above 3.0 mg/kg - Table 6 : Evaluation of the Cr(VI) results in 100 leather samples En ligne : https://drive.google.com/file/d/13VmY0k59wMY6TKIykzgnXLA9wEalFumN/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=36106 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
22841	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Evaluation of chemical products in leather post-tanning process and their influence in presence of neutral salts in raw tannery effluent / M. V. Moreira in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 4 (04/2019)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIV, N° 4 (04/2019) . - p. 108-117 Titre : Evaluation of chemical products in leather post-tanning process and their influence in presence of neutral salts in raw tannery effluent Type de document : texte imprimé Auteurs : M. V. Moreira, Auteur ; Everton Hansen, Auteur ; G. Giacomolli, Auteur ; F. D. P. Morisso, Auteur ; P. M. Aquim, Auteur Année de publication : 2019 Article en page(s) : p. 108-117 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation Chlorure de sodium Le chlorure de sodium est un composé chimique de formule NaCl. On l'appelle plus communément sel de table ou de cuisine, ou tout simplement sel dans le langage courant. C'est le principal produit dissous dans l'eau de mer ; on l'appelle alors sel marin. On l'obtient : dans des marais salants par évaporation de l'eau de mer, dans des mines, par extraction du sel gemme (halite) ou en le synthétisant lors de réactions à hautes températures entre du dichlore (Cl2) et du sodium métallique (Na). Le chlorure de sodium est utilisé dans l'industrie chimique pour produire du chlore, de la soude caustique et de l’hydrogène. Chromatographie par échange d'ions Eaux usées -- Analyse Post-tannage Produits chimiques Spectroscopie d'absorption Sulfate de sodium Le sulfate de sodium est un composé chimique courant formé d'un ion sulfate et de deux ions sodium. Lorsqu'il est anhydre, il prend l'apparence d'un solide cristallin blanc de formule chimique Na2SO4. La forme déca-hydratée, Na2SO4·10H2O, est connue sous le nom de sel de Glauber ou mirabilite. Parmi un grand nombre d'usages différents, les principales utilisations du sulfate de sodium concernent la fabrication des détergents et dans le procédé de Kraft de traitement de la pâte à papier. La moitié environ de la production mondiale provient de l'extraction de la forme naturelle décahydratée, et l'autre moitié de productions secondaires dans des procédés de l'industrie chimique. Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In the leather industry, several chemical products are used for the transformation of the raw hide into the demanded final product. The production flow and the post-tanning of wet-blue leathers may vary according to the available technologies and the type of final item produced. Previous operations and processes are also relevant, particularly the steps of unhairing-liming and tanning process. During the effluent treatment process, there is a great difficulty in removing soluble salts, such as sodium chloride and sodium sulfate in conventional effluent treatment stations. These salts might compromise the biological treatment of tannery wastewater and adversely impact the receiving water bodies, causing environmental pollution. Further, the presence of chlorides and sulfates might interfere in the implementation of the bath reuse system or in the recycling of the treated effluents in the post-tanning process. Therefore, this work aims to investigate the measures used to control the production of sodium neutral salts, such as the sodium chlorides and sulfates, contained in the chemical compounds uses in the industry that performs post-tanning in bovine wet-blue leather, mostly for automotive and furniture upholstery. The work was carried out following the production of the factory for six months, with approximately 1485 whole wet-blue leathers being processed per day, with an average production of 7500 m² of crust leathers per day. The work methodology was based on the diagnosis of the initial situation of the tannery, chemical analyses of the supplies employed and in proposals of action based on this initial profile. The work also involves the checking of the water consumption and the evaluation of the residual baths. The identification of the chemical products in the formulation that contribute directly to the presence of neutral salts in the gross effluent and their presence in the residual baths were among the main results observed in the present work. In order to determinate sodium, chlorides and sulfates, two methodologies were tested (ion chromatography, for chlorides and sulfates ; and absorption spectroscopy, for sodium), showing similar results. Note de contenu : - EXPERIMENTAL : Gathering of production data - Identification and characterization of the main chemical supplies used - Characterization of the critical chemical products regarding the presence of neutral salts - Characterization of the residual baths and water consumption measurements - RESULTS AND DISCUSSION : Production data - Chemical supplies used in the formulations - Characterization of the critical chemical products regarding the presence of neutral salts - Water consumption - Characterization of the residual baths En ligne : https://drive.google.com/file/d/1eNSGuiZwOEvPyZjfpTvEoYbVILy5-ADX/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32272 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
20830	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Influence of microwave on chromium complex composition in tanning liquor / Jinwei Zhang in JOURNAL OF LEATHER SCIENCE AND ENGINEERING, Vol. 2 (Année 2020)  

[article]  inJOURNAL OF LEATHER SCIENCE AND ENGINEERING > Vol. 2 (Année 2020) . - 11 p. Titre : Influence of microwave on chromium complex composition in tanning liquor Type de document : texte imprimé Auteurs : Jinwei Zhang, Auteur ; Wuyong Chen, Auteur ; Carmen Gaidau, Auteur Année de publication : 2020 Article en page(s) : 11 p. Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chromatographie par échange d'ions Chromatographie sur gel Complexes métalliques Liqueurs de tannage Micro-ondes Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Since microwave irradiation could promote hydrolysis and olation of chromium tanning liquor, but the influence of microwave on chromium complex component in the liquor was still unknown. Chromium sulphate solution (0% basicity) and 33% basicity chromium tanning liquor were subjected microwave (MW) and water bath (WB) heating, and the samples without any warming were regarded as control. Ion exchange chromatography (IEC) and gel filtration chromatography (GFC) were used to measure the charge composition and molecular size of chromium complexes in each sample. FT-IR was used to characterize the structure of chromium complexes in each composition separated by IEC. Moreover, the chromium tanning liquor after warming was used in hide powder tanning trials to illustrate whether microwave would affect its tanning ability. The results show there are more high positive charge and large molecular size complexes in chromium tanning liquor after warming but the phenomena are more significant in MW samples compared with WB due to non-thermal effect of microwave. In addition, microwave has more powerful effect on 33% basicity chromium tanning liquor hydrolysis and olation to generate larger molecular size complexes. In FT-IR results, the combination pattern between chromium and ligands are changed after warming but there is no difference between WB and MW. The chromium exhaustion and thermal stability of hide powder tanned with chromium tanning liquor after microwave irradiation are both higher. It could conclude that both thermal and non-thermal effects of microwave promote the process together, and the non-thermal effect leads to more high positive charge and large molecular size complexes and has stronger influence on high polarity system. In short, this work would provide theoretical basis for applying microwave in tanning agent modification and chrome tanning process further. Note de contenu : - EXPERIMENTAL : Reagents and materials - Instruments - Sample preparation - Determination methods - RESULTS AND DISCUSSION : The influence of microwave on chromium charge composition in tanning liquor - The influence of microwave on chromium molecular size in tanning liquors - The influence of microwave on chromium complex structure - The influence of microwave on tanning ability of chromium tanning liquor - Table 1 : The content of each component in 0% basicity chromium sulphate tanning liquor warmed under different methods - Table 2 : The content of each component in 33% basicity chromium sulphate tanning liquor warmed under different methods - Table 3 : FT-IR absorption peaks of SO42− in chromium complex from each component in 0% basicity chromium sulphate tanning liquor - Table 4 : FT-IR absorption peaks of SO42− in chromium complex from each component in 33% basicity chromium sulphate tanning liquor - Table 5 : The thermal behaviors and chrome content of hide powder tanned by chrome tanning liquor treated by different method DOI : https://doi.org/10.1186/s42825-020-00024-1 En ligne : https://link.springer.com/content/pdf/10.1186/s42825-020-00024-1.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37334 [article]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Separation, speciation and quantification of both chromium (VI) and chromium (III) in tanned leather samples : a comparative study and validation of analytical methods / Mónica Gisel Arellano-Sánchez in COLLAGEN AND LEATHER, Vol. 5 (2023)  

[article]  inCOLLAGEN AND LEATHER > Vol. 5 (2023) . - 16 p. Titre : Separation, speciation and quantification of both chromium (VI) and chromium (III) in tanned leather samples : a comparative study and validation of analytical methods Type de document : texte imprimé Auteurs : Mónica Gisel Arellano-Sánchez, Auteur ; Juliette Vievard, Auteur ; Lamia Moufarrej, Auteur ; Christine Devouge-Boyer, Auteur ; Marie Hubert-Roux, Auteur ; Carlos Afonso, Auteur ; Mélanie Mignot, Auteur Année de publication : 2023 Article en page(s) : 16 p. Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse quantitative (chimie) Chromatographie par échange d'ions Chrome hexavalent Chrome trivalent Cuirs et peaux -- Analyse Spéciation (chimie) Spectrométrie de masse Tannage au chrome Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In the present work, a comparative study of analytical methods for the simultaneous and quantitative determination of trivalent and hexavalent chromium is presented. For the analysis by ion chromatography-inductively coupled plasma-mass spectrometry, two different columns were tested, as well as different mobile phases and different pH of the samples. The optimized analytical method permitted the separation of Cr(III) and Cr(VI) using 75 mmol/L NH4NO3 pH 3 as chromatographic eluent. The method was validated and applied to real samples, allowing the determination of both species simultaneously, even when there is a huge difference of concentration between Cr(III) and Cr(VI). Limit of detection and limit of quantification for Cr(III) were found to be 0.016 and 0.054 μg/L (0.3 and 1.1 μg/kg), respectively, and for Cr(VI) 0.13 and 0.43 μg/L (7 and 22 μg/kg), respectively. Possible species interconversions were monitored through the use of chromium isotopic standards, which confirmed that the optimized methodology preserves chromium speciation during extraction and analysis. Fourier-transform ion cyclotron resonance-mass spectrometry permitted the structure elucidation of the complex formed during ethylenediaminetetraacetic acid extraction. Note de contenu : - EXPERIMENTAL : Instrumentation - Materials - Methodology - RESULTS AND DISCUSSION : Speciation by IC-ICP-MS - FTICR MS - Validation - Table 1 : Optimized operating conditions for ICP-MS - Table 2 : FTICR parameters for the analysis of the chromium-EDTA complex - Table 3 : Retention times of the different peaks observed after injecting Cr(III)-EDTA− at different pH - Table 4 : Chromatographic conditions of the study by Hernandez et al. [19] versus conditions of the current study - Table 5 : Retention times of Cr species observed at different sample conditions (pH and redox potential) - Table 6 : Ion formula predicition - Table 7 : Interday precision for Cr(III) determination. 3 different samples were analyzed each day - Table 8 : Cr(VI) determination from a leather sample DOI : https://doi.org/10.1186/s42825-023-00125-7 En ligne : https://link.springer.com/content/pdf/10.1186/s42825-023-00125-7.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40068 [article]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

---

1 (1 - 5 / 5)