E. Miadoková, H. Dingová, Grigorij Kogan, Denisa Liszeková, P. Rauko
ABSTRACT Two samples of the acid-mine water (AMW) containing heavy metals were collected in the year 1995 and 1998 in the former mining area of Banská Štiavnica-Šobov (Slovakia), and assayed for their genotoxic potential by the Ames assay and the DNA-topology assay. The content of toxic metal elements, determined by atomic absorption spectroscopy, was decreased in the sample of AMW collected in the year 1998 in comparison with that determined in the year 1995. The sample collected in 1995 was genotoxic after its application on bacterial strain Salmonella typhimurium TA97 (without metabolic activation), and TA102 (with metabolic activation). The sample collected in 1998 did not increase the frequency of his+ revertants in the same bacterial strains. Moreover, the DNA-topology assay (which facilitates electrophoretic monitoring and densitometric quantification of changes in a plasmid DNA structure) revealed the presence of 81.3% of the slowly migrating plasmid DNA, and 18.2% of the relaxed plasmid DNA after incubation of the plasmid DNA with the sample collected in 1998, and respectively after the joint incubation of this sample with glutathione and hydrogen peroxide.
{"title":"DIFFERENT GENOTOXICOLOGICAL RESPONSES OF MINE WATERS CONTAINING HEAVY METALS","authors":"E. Miadoková, H. Dingová, Grigorij Kogan, Denisa Liszeková, P. Rauko","doi":"10.1081/TMA-120006688","DOIUrl":"https://doi.org/10.1081/TMA-120006688","url":null,"abstract":"ABSTRACT Two samples of the acid-mine water (AMW) containing heavy metals were collected in the year 1995 and 1998 in the former mining area of Banská Štiavnica-Šobov (Slovakia), and assayed for their genotoxic potential by the Ames assay and the DNA-topology assay. The content of toxic metal elements, determined by atomic absorption spectroscopy, was decreased in the sample of AMW collected in the year 1998 in comparison with that determined in the year 1995. The sample collected in 1995 was genotoxic after its application on bacterial strain Salmonella typhimurium TA97 (without metabolic activation), and TA102 (with metabolic activation). The sample collected in 1998 did not increase the frequency of his+ revertants in the same bacterial strains. Moreover, the DNA-topology assay (which facilitates electrophoretic monitoring and densitometric quantification of changes in a plasmid DNA structure) revealed the presence of 81.3% of the slowly migrating plasmid DNA, and 18.2% of the relaxed plasmid DNA after incubation of the plasmid DNA with the sample collected in 1998, and respectively after the joint incubation of this sample with glutathione and hydrogen peroxide.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87259423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Serfor-Armah, B. Nyarko, E. Akaho, A. Kyere, S. Osae, K. Oppong-Boachie
ABSTRACT The essential elements in six traditional Ghanaian plant medicines used at the Center for Scientific Research into Plant Medicine (CSRPM), Mampong-Akwapim, Ghana, for the management and cure of various diseases were determined by Instrumental Neutron Activation Analysis (INAA), using thermal neutrons at a flux of 5 E 11 ns−1 cm−2. The plant medicines were: Ninga powder, Lippia tea, Ritchiea powder, Momordica powder, Kenken powder and Fefe powder. The samples were analysed without any chemical treatment. A total of seventeen elements namely Al, Br, Ca, Cl, Co, Cu, Cr, K, Mn, Mg, Na, Rb, Sb, Sc, Ta, V and Zn have been determined. Of these Sb and Sc were found to be present at the trace level, Br, Co, Cu, Cr, Mn, Rb, Ta, V and Zn at the minor level, while Al, Ca, Cl, K, Mg and Na were generally at the major level. The differences in the concentration of the elements may be attributed mainly to soil composition and the climate in which the plants grow. The method was validated by analysing the NIST Standard Reference Material (SRM-1571) and it was found that the elemental concentrations measured in the SRM-1571 were within ± 10%.
加纳Mampong-Akwapim植物医学科学研究中心(ccsrpm)使用仪器中子活化分析(INAA)测定了六种加纳传统植物药物中的基本元素，用于管理和治疗各种疾病，使用热中子通量为5 E 11 ns−1 cm−2。植物药为:宁咖散、利皮茶散、利氏散、苦瓜散、肯根散、铁茶散。这些样品未经任何化学处理就进行了分析。共测定了Al、Br、Ca、Cl、Co、Cu、Cr、K、Mn、Mg、Na、Rb、Sb、Sc、Ta、V、Zn等17种元素。其中Sb、Sc以微量水平存在，Br、Co、Cu、Cr、Mn、Rb、Ta、V、Zn以微量水平存在，Al、Ca、Cl、K、Mg、Na以微量水平存在。这些元素浓度的差异可能主要归因于土壤成分和植物生长的气候。通过分析NIST标准参考物质(SRM-1571)对方法进行验证，发现SRM-1571所测元素浓度在±10%以内。
{"title":"MULTIELEMENTAL ANALYSIS OF SOME TRADITIONAL PLANT MEDICINES USED IN GHANA","authors":"Y. Serfor-Armah, B. Nyarko, E. Akaho, A. Kyere, S. Osae, K. Oppong-Boachie","doi":"10.1081/TMA-120006687","DOIUrl":"https://doi.org/10.1081/TMA-120006687","url":null,"abstract":"ABSTRACT The essential elements in six traditional Ghanaian plant medicines used at the Center for Scientific Research into Plant Medicine (CSRPM), Mampong-Akwapim, Ghana, for the management and cure of various diseases were determined by Instrumental Neutron Activation Analysis (INAA), using thermal neutrons at a flux of 5 E 11 ns−1 cm−2. The plant medicines were: Ninga powder, Lippia tea, Ritchiea powder, Momordica powder, Kenken powder and Fefe powder. The samples were analysed without any chemical treatment. A total of seventeen elements namely Al, Br, Ca, Cl, Co, Cu, Cr, K, Mn, Mg, Na, Rb, Sb, Sc, Ta, V and Zn have been determined. Of these Sb and Sc were found to be present at the trace level, Br, Co, Cu, Cr, Mn, Rb, Ta, V and Zn at the minor level, while Al, Ca, Cl, K, Mg and Na were generally at the major level. The differences in the concentration of the elements may be attributed mainly to soil composition and the climate in which the plants grow. The method was validated by analysing the NIST Standard Reference Material (SRM-1571) and it was found that the elemental concentrations measured in the SRM-1571 were within ± 10%.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86224249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Resonance Rayleigh light-scattering (RRLS) of Thiamine Hydrochloride (TH)–nucleic acids–cetyl trimethyl ammonium bromide system and its analytical application was studied by using a common spectrofluorimeter, by which nucleic acids at nanogram level can be determined. TH–CTMAB reacts rapidly with nucleic acids at room temperature and the intensity of the weak common Rayleigh light scattering (RLS) of TH–CTMAB is enhanced remarkably by nucleic acids. The effective factors were studied and the optimum conditions were obtained. In TH–nucleic acids–CTMAB system, the formation of an ion association complex of TH–nucleic acids–CTMAB is considered as the reason of the enhancement of RRLS. It was also proved that the RRLS and RLS appeared in the same light scattering process. Linear relationships were found between the enhanced RRLS intensity at 406 nm and nucleic acids concentration in the range 8.0 × 10−9–1.0 × 10−5 g/mL for fish sperm DNA (fsDNA), 2.0 × 10−8–1.0 × 10−5 g/mL for calf thymus DNA (ctDNA), 1.0 × 10−8–1.0 × 10−5 g/mL for yeast RNA (yRNA). The detection limits are 2.6, 11.0, 6.3, ng/mL for fsDNA, ctDNA and yRNA, respectively. Three synthetic samples were determined with satisfaction.
{"title":"RESONANCE RAYLEIGH LIGHT-SCATTERING OF THIAMINE HYDROCHLORIDE–NUCLEIC ACIDS–CETYL TRIMETHYL AMMONIUM BROMIDE SYSTEMS AND THEIR ANALYTICAL APPLICATION","authors":"Rutao Liu, Jinghe Yang, Xia Wu, Zhengmin Li, Changxia Sun, F. Huang","doi":"10.1081/TMA-120006682","DOIUrl":"https://doi.org/10.1081/TMA-120006682","url":null,"abstract":"ABSTRACT Resonance Rayleigh light-scattering (RRLS) of Thiamine Hydrochloride (TH)–nucleic acids–cetyl trimethyl ammonium bromide system and its analytical application was studied by using a common spectrofluorimeter, by which nucleic acids at nanogram level can be determined. TH–CTMAB reacts rapidly with nucleic acids at room temperature and the intensity of the weak common Rayleigh light scattering (RLS) of TH–CTMAB is enhanced remarkably by nucleic acids. The effective factors were studied and the optimum conditions were obtained. In TH–nucleic acids–CTMAB system, the formation of an ion association complex of TH–nucleic acids–CTMAB is considered as the reason of the enhancement of RRLS. It was also proved that the RRLS and RLS appeared in the same light scattering process. Linear relationships were found between the enhanced RRLS intensity at 406 nm and nucleic acids concentration in the range 8.0 × 10−9–1.0 × 10−5 g/mL for fish sperm DNA (fsDNA), 2.0 × 10−8–1.0 × 10−5 g/mL for calf thymus DNA (ctDNA), 1.0 × 10−8–1.0 × 10−5 g/mL for yeast RNA (yRNA). The detection limits are 2.6, 11.0, 6.3, ng/mL for fsDNA, ctDNA and yRNA, respectively. Three synthetic samples were determined with satisfaction.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77014931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT A comparative investigation of seven heavy metals (Cr, Mn, Fe, Ni, Cu, Cd and Pb) in mosses, lichens and trees over the Kozani-Ptolemaïda-Amynteon lignite basin in West Macedonia, Greece has carried out. In this region there are four lignite power plants producing about 70% of the electric energy of the country. Experiments have determined both concentrations of these elements and transfer factors that are defined as the ratio of the concentration of a given element in an investigated organism to the concentration of the same element in the soil. This study indicates that compared to trees, mosses and lichens have a higher capacity for absorbing and accumulating heavy metals. The conifer Pinus nigra seems to have a higher affinity for these metals than the other tree species, which is manifested in a better correlation of the distribution functions as well as greater values of transfer factor. Compared with unpolluted areas, the concentration of chromium, manganese, iron, nickel, cadmium and lead are systematically increasing in tree leaves in the vicinity of all four power plants.
{"title":"HEAVY METALS DISTRIBUTION IN SOME LICHENS, MOSSES, AND TREES IN THE VICINITY OF LIGNITE POWER PLANTS FROM WEST MACEDONIA, GREECE","authors":"L. Tsikritzis, S. Ganatsios, O. Duliu, T. Sawidis","doi":"10.1081/TMA-120006685","DOIUrl":"https://doi.org/10.1081/TMA-120006685","url":null,"abstract":"ABSTRACT A comparative investigation of seven heavy metals (Cr, Mn, Fe, Ni, Cu, Cd and Pb) in mosses, lichens and trees over the Kozani-Ptolemaïda-Amynteon lignite basin in West Macedonia, Greece has carried out. In this region there are four lignite power plants producing about 70% of the electric energy of the country. Experiments have determined both concentrations of these elements and transfer factors that are defined as the ratio of the concentration of a given element in an investigated organism to the concentration of the same element in the soil. This study indicates that compared to trees, mosses and lichens have a higher capacity for absorbing and accumulating heavy metals. The conifer Pinus nigra seems to have a higher affinity for these metals than the other tree species, which is manifested in a better correlation of the distribution functions as well as greater values of transfer factor. Compared with unpolluted areas, the concentration of chromium, manganese, iron, nickel, cadmium and lead are systematically increasing in tree leaves in the vicinity of all four power plants.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90961721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Sensitive methods for the spectrophotometric determination of trace amounts of vanadium(IV) are described. The methods utilize the ternary complexes formed by reacting vanadium(IV) with imipramine or chlorprothixene hydrochlorides in the presence of chrome azurol S and methylcellulose. The composition and the absorption spectra in the UV–VIS and IR regions of the ion association complexes are described.
{"title":"SPECTROPHOTOMETRIC DETERMINATION OF VANADIUM(IV) BY TERNARY COMPLEXES OF CHROME AZUROL S WITH IMIPRAMINE AND CHLORPROTHIXENE","authors":"B. Starczewska","doi":"10.1081/TMA-120006683","DOIUrl":"https://doi.org/10.1081/TMA-120006683","url":null,"abstract":"ABSTRACT Sensitive methods for the spectrophotometric determination of trace amounts of vanadium(IV) are described. The methods utilize the ternary complexes formed by reacting vanadium(IV) with imipramine or chlorprothixene hydrochlorides in the presence of chrome azurol S and methylcellulose. The composition and the absorption spectra in the UV–VIS and IR regions of the ion association complexes are described.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77321265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT The estimation of Ca, Mg, Zn, Fe, Cr and Ni in twenty samples of used and unused lubricating oils were carried out using atomic absorption spectroscopic technique (AAS). The results show an appreciable increase in the concentration values of Fe, Cr and Ni in used oil samples.
{"title":"ATOMIC ABSORPTION ANALYSIS OF TRACE METAL CONTENT IN LUBRICATING OILS","authors":"M. A. Rauf, M. Ikram, S. Khaliq","doi":"10.1081/TMA-120006686","DOIUrl":"https://doi.org/10.1081/TMA-120006686","url":null,"abstract":"ABSTRACT The estimation of Ca, Mg, Zn, Fe, Cr and Ni in twenty samples of used and unused lubricating oils were carried out using atomic absorption spectroscopic technique (AAS). The results show an appreciable increase in the concentration values of Fe, Cr and Ni in used oil samples.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81445538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Trace metal concentrations of mineral spring waters in central Anatolia, Turkey were investigated by total reflection X-ray fluorescence spectrometry (TXRF). The concentrations of trace heavy-metal ions were quantitatively determined with an internal Ga standard. The element concentrations obtained by TXRF are comparable to results obtained by graphite furnace absorption spectrometry (GFAAS) after separation-preconcentration on an Amberlite XAD-4 column and inductively coupled plasma-mass spectrometry (ICP-MS).
{"title":"DETERMINATION OF SOME TRACE ELEMENTS IN MINERAL SPRING WATERS BY TOTAL REFLECTION X-RAY FLUORESCENCE SPECTROMETRY (TXRF)","authors":"M. Doğan, M. Soylak","doi":"10.1081/TMA-120003728","DOIUrl":"https://doi.org/10.1081/TMA-120003728","url":null,"abstract":"ABSTRACT Trace metal concentrations of mineral spring waters in central Anatolia, Turkey were investigated by total reflection X-ray fluorescence spectrometry (TXRF). The concentrations of trace heavy-metal ions were quantitatively determined with an internal Ga standard. The element concentrations obtained by TXRF are comparable to results obtained by graphite furnace absorption spectrometry (GFAAS) after separation-preconcentration on an Amberlite XAD-4 column and inductively coupled plasma-mass spectrometry (ICP-MS).","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72549654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. O. B. Ewa, Denes Bodizes, S. Czifrus, M. Balla, Z. Molnár
ABSTRACT The full energy peak efficiency values of an HPGe detector covering an energy range of 81–1836 keV were determined for a Marinelli beaker photon source-geometry. Detector efficiency for energy depositions from source volumes of 300 and 400 ml were simulated using the Monte Carlo method. Experimental data points from measurements of standard sources were used in validating the method while least-squares functions were used to obtain fitted values from the experimental data sets. The efficiency values from the Monte Carlo simulation, experimental results, and fitted functions were found to be in agreement with deviations of less than 10% for most data points.
{"title":"GERMANIUM DETECTOR EFFICIENCY FOR A MARINELLI BEAKER SOURCE-GEOMETRY USING THE MONTE CARLO METHOD","authors":"I. O. B. Ewa, Denes Bodizes, S. Czifrus, M. Balla, Z. Molnár","doi":"10.1081/TMA-120003721","DOIUrl":"https://doi.org/10.1081/TMA-120003721","url":null,"abstract":"ABSTRACT The full energy peak efficiency values of an HPGe detector covering an energy range of 81–1836 keV were determined for a Marinelli beaker photon source-geometry. Detector efficiency for energy depositions from source volumes of 300 and 400 ml were simulated using the Monte Carlo method. Experimental data points from measurements of standard sources were used in validating the method while least-squares functions were used to obtain fitted values from the experimental data sets. The efficiency values from the Monte Carlo simulation, experimental results, and fitted functions were found to be in agreement with deviations of less than 10% for most data points.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84609692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Reiche, C. Vignaud, L. Favre-Quattropani, M. Menu
ABSTRACT In this paper we present fluorine analysis by transmission electron microscopy (TEM-EDX) and measurement of concentration profiles by nuclear reaction analysis with a proton beam (PIGE and microPIGE) on various archaeological bone and dentine material. Fluorine is present as trace element in modern bone and dentine (100–1000 ppm) whose mineral phase consists of a poorly crystalline hydroxylapatite (Ca10(PO4)6 − x(CO3)x(OH)2+x). During the burial time, archaeological bone and dentine accumulate F in the apatite structure. TEM-EDX can evidence fluorine accumulation on a very localised, nanometric scale if its concentration exceeds 1 wt.%. On the contrary, PIGE and microPIGE permit detection of fluorine with a high sensitivity (limit of detection 30 ppm) on a microscopic or macroscopic level. Its spatial resolution can be of 10 µm, but is, however, insufficient to resolve the distribution of fluorine within the bone and dentine apatite nanocrystals. We show the complementarity of the information delivered by each technique on examples of ancient bone and dentine remains from different archaeological and geological sites, dating from the Neolithic Age to the Miocene. Furthermore, the potential to reveal detailed diagenetic changes of bone material of TEM-EDX and of PIGE is evaluated. This is important for the determination of information on the life style of prehistoric societies. Specifically, we show different steps of F enrichment depending on the age and the environment of the samples. Nevertheless, the fluorine content cannot be correlated to the age of the specimens, and high variations have been observed within one bone sample.
{"title":"FLUORINE ANALYSIS IN BIOGENIC AND GEOLOGICAL APATITE BY ANALYTICAL TRANSMISSION ELECTRON MICROSCOPY AND NUCLEAR REACTION ANALYSIS","authors":"I. Reiche, C. Vignaud, L. Favre-Quattropani, M. Menu","doi":"10.1081/TMA-120003725","DOIUrl":"https://doi.org/10.1081/TMA-120003725","url":null,"abstract":"ABSTRACT In this paper we present fluorine analysis by transmission electron microscopy (TEM-EDX) and measurement of concentration profiles by nuclear reaction analysis with a proton beam (PIGE and microPIGE) on various archaeological bone and dentine material. Fluorine is present as trace element in modern bone and dentine (100–1000 ppm) whose mineral phase consists of a poorly crystalline hydroxylapatite (Ca10(PO4)6 − x(CO3)x(OH)2+x). During the burial time, archaeological bone and dentine accumulate F in the apatite structure. TEM-EDX can evidence fluorine accumulation on a very localised, nanometric scale if its concentration exceeds 1 wt.%. On the contrary, PIGE and microPIGE permit detection of fluorine with a high sensitivity (limit of detection 30 ppm) on a microscopic or macroscopic level. Its spatial resolution can be of 10 µm, but is, however, insufficient to resolve the distribution of fluorine within the bone and dentine apatite nanocrystals. We show the complementarity of the information delivered by each technique on examples of ancient bone and dentine remains from different archaeological and geological sites, dating from the Neolithic Age to the Miocene. Furthermore, the potential to reveal detailed diagenetic changes of bone material of TEM-EDX and of PIGE is evaluated. This is important for the determination of information on the life style of prehistoric societies. Specifically, we show different steps of F enrichment depending on the age and the environment of the samples. Nevertheless, the fluorine content cannot be correlated to the age of the specimens, and high variations have been observed within one bone sample.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77306703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Co-impregnated ruthenium–manganese bimetallic catalysts supported on high-surface area silica support were exposed to high-temperature reduction–oxidation–reduction (R/O/R) treatment to generate catalytic surfaces having specific geometry. The impact of R/O/R modifications was probed via a model Fischer-Tropsch synthesis (FTS) reaction aided by various characterisation techniques (TEM, XPS, s-SIMS, selective chemisorption). The characterisation results indicated that alternating reduction and oxidation of the catalyst was propitious to the formation of a specific surface landscape enriched in Ru : Mn bimetallic sites as well as in ruthenium and manganese oxides. The increase in metal dispersion and BET surface area following R/O/R exposures of the catalysts was due to re-dispersion of particles in the range of 2–10 nm, to surface modification, and to changes in active sites. The presence of ruthenium oxide, manganese oxide and Ru : Mn was likely to be at the origin of the enhancement in the production of unsaturated hydrocarbons in the FTS reaction.
{"title":"SURFACE MODIFICATION OF SUPPORTED Ru : Mn/SiO2 FISCHER-TROPSCH SYNTHESIS CATALYSTS","authors":"S. Hussain, F. Larachi","doi":"10.1081/TMA-120003724","DOIUrl":"https://doi.org/10.1081/TMA-120003724","url":null,"abstract":"ABSTRACT Co-impregnated ruthenium–manganese bimetallic catalysts supported on high-surface area silica support were exposed to high-temperature reduction–oxidation–reduction (R/O/R) treatment to generate catalytic surfaces having specific geometry. The impact of R/O/R modifications was probed via a model Fischer-Tropsch synthesis (FTS) reaction aided by various characterisation techniques (TEM, XPS, s-SIMS, selective chemisorption). The characterisation results indicated that alternating reduction and oxidation of the catalyst was propitious to the formation of a specific surface landscape enriched in Ru : Mn bimetallic sites as well as in ruthenium and manganese oxides. The increase in metal dispersion and BET surface area following R/O/R exposures of the catalysts was due to re-dispersion of particles in the range of 2–10 nm, to surface modification, and to changes in active sites. The presence of ruthenium oxide, manganese oxide and Ru : Mn was likely to be at the origin of the enhancement in the production of unsaturated hydrocarbons in the FTS reaction.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73189063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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