Sample preparation procedures for determination of Cr2O3 in leather samples using ICP-AES and AAS / K. A. Eid in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 7 (07/2004)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 7 (07/2004) . - p. 275-279 Titre : Sample preparation procedures for determination of Cr2O3 in leather samples using ICP-AES and AAS Type de document : texte imprimé Auteurs : K. A. Eid, Auteur ; M. A. Eid, Auteur ; A. El Askar, Auteur ; A. A. Madhy, Auteur ; E. H. Nashy, Auteur Année de publication : 2004 Article en page(s) : p. 275-279 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Three different sample preparation procedures were applied to leather samples, representing four different steps of the tanning process namely, after the tanning step (wet blue), after the retanning step (crust), after normal finishing and after a silicon finishing process. The sample preparation procedures are the conventional procedure in which the samples are fused at 800°C with a mixture of Na2CO3, K2CO3 and borax followed by dissolving in boiling water and filtering. The other two suggested procedures are an ashing/fusion procedure in which the leather sample is ashed at 1000°C followed by an alkali fusion step with NaOH, Na2O2 and Na2CO3 while in the second procedure the leather sample is refluxed with concentrated HNO3. Both procedures lead to complete dissolution of the leather sample. Chromium and consequently Cr2O3 was determined in the prepared sample solutions by using inductively coupled plasma atomic emission spectrometry (ICP-AES) and flame atomic absorption spectrometry (AAS). The obtained results revealed that the direct acid digestion procedure by requiring minimum additive chemicals and no fusion step without leaving any residue represents a convenient procedure for the complete dissolution of leather samples that can be analyzed for Cr using an appropriate analytical technique such as AAS or ICP-AES. The accuracy of the conventional method could be increased by increasing the Na2CO3/ K2CO3/ borax mixture from 4-fold that of the leather sample to 5-fold and, in addition, by raising the ashing temperature from 800°C to 900°C in order to ensure the complete dissolution of the sample. En ligne : https://drive.google.com/file/d/1ntNZ8bNrnADU5p-DwqlbtNIV1K00iqG_/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4213 [article]

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Speciation of chromium ions in tannery effluents and subsequent determination of Cr (VI) by ICP-AES / M. A. Eid in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 11 (11/2002)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVII, N° 11 (11/2002) . - p. 451-455 Titre : Speciation of chromium ions in tannery effluents and subsequent determination of Cr (VI) by ICP-AES Type de document : texte imprimé Auteurs : M. A. Eid, Auteur ; E. A. Al-Ashkara, Auteur ; K. A. Eid, Auteur ; E. H. Nashy, Auteur ; E. H. Borai, Auteur Année de publication : 2002 Article en page(s) : p. 451-455 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Speciation of chromium in the effluents of two local tanneries has been carried out using two procedures. In the first procedure, Cr(III) was precipitated as Cr(OH)3 while in the second a cation exchange resin (Amberlite® IR 120H) was used for its preconcentration. The separated Cr(VI) was then determined in the solution with the aid of inductively coupled plasma-atomic emission spectrometry (ICP-AES). The efficiency of the two procedures was first tested by analyzing synthetically prepared solutions containing the two Cr species. The two methods were applied for the determination of Cr(VI) in samples collected from different sites in the two tanneries. The results revealed that Cr(VI) is detected in the wet finishing step of the tanning process of the two tanneries at average concentrations of 10.5 and 16.6 µg ml-1 respectively and is also present at a much lower level namely at 0.42 and 2.39 µg ml-1 in the final drain of the two plants respectively. The validation of the suggested methods was confirmed by ion chromatography. It is advised to collect the wastewater of the wet-finishing Speciation of chromium in the effluents of two local tanneries has been carried out using two procedures. In the first procedure, Cr(III) was precipitated as Cr(OH)3 while in the second a cation exchange resin (Amberlite® IR 120H) was used for its preconcentration. The separated Cr(VI) was then determined in the solution with the aid of inductively coupled plasma-atomic emission spectrometry (ICP-AES). The efficiency of the two procedures was first tested by analyzing synthetically prepared solutions containing the two Cr species. The two methods were applied for the determination of Cr(VI) in samples collected from different sites in the two tanneries. The results revealed that Cr(VI) is detected in the wet finishing step of the tanning process of the two tanneries at average concentrations of 10.5 and 16.6 µg ml-1 respectively and is also present at a much lower level namely at 0.42 and 2.39 µg ml-1 in the final drain of the two plants respectively. The validation of the suggested methods was confirmed by ion chromatography. It is advised to collect the wastewater of the wet-finishing step separately and pass it through an Al2O3 column for the removal of chromium, before it is allowed to mix with the rest of the plant effluents. En ligne : https://drive.google.com/file/d/1OrqM2GAHVHvVd3aXBGpUb_dwHRXvMArl/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4245 [article]

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