Abstract A selective, reproducible, and sensitive spectrophotometric method for uranyl determination was developed. The method is based on the selective complexation reaction of ions with 2-(2-benzothiazolylazo)phenol(I), -4-methoxyphenol (II), and -3-hydroxyphenol(III) in the presence of sodium lauryl sulphate. The potentiality of the prepared reagents as new chromogenic ones for the determination of ions are studied by extensive investigations of the optimum conditions favoring the formation of the colored complexes. The method allows the determination of in the range of 0.05–1.60, 0.05–1.40, and 0.05–1.70 µg mL−1 at λ max 585, 608, and 599 nm using reagents I, II, and III, respectively. For more accurate results, Ringbom optimum concentration ranges were found to be 0.10–1.60 µg mL−1. The molar absorptivity, Sandell sensitivity, detection, and quantification limits are also evaluated. The interfering ions and their tolerance limits have been studied. The method was successfully applied to the determination of uranium from standard ores, geological samples, and synthetic matrices.
建立了一种选择性、重复性好、灵敏度高的分光光度法测定铀酰的方法。该方法是基于离子与2-(2-苯并噻唑偶氮)苯酚(I)、-4-甲氧基苯酚(II)和-3-羟基苯酚(III)在十二烷基硫酸钠存在下的选择性络合反应。通过对有色络合物形成的最佳条件的广泛研究，研究了所制备试剂作为离子测定新显色试剂的潜力。该方法允许测定范围在0.05-1.60,0.05-1.40，和0.05-1.70µg mL−1在λ max 585, 608，和599 nm分别使用试剂I, II，和III。为了获得更准确的结果，Ringbom的最佳浓度范围为0.10 ~ 1.60µg mL−1。摩尔吸收率，桑德尔灵敏度，检测和定量限也进行了评估。研究了干扰离子及其容限。该方法成功地应用于标准矿石、地质样品和合成基质中铀的测定。
{"title":"Simple Spectrophotometric Method for the Quantitative Determination of Uranium","authors":"A. Amin, E. El-Mossalamy","doi":"10.1081/TMA-120025815","DOIUrl":"https://doi.org/10.1081/TMA-120025815","url":null,"abstract":"Abstract A selective, reproducible, and sensitive spectrophotometric method for uranyl determination was developed. The method is based on the selective complexation reaction of ions with 2-(2-benzothiazolylazo)phenol(I), -4-methoxyphenol (II), and -3-hydroxyphenol(III) in the presence of sodium lauryl sulphate. The potentiality of the prepared reagents as new chromogenic ones for the determination of ions are studied by extensive investigations of the optimum conditions favoring the formation of the colored complexes. The method allows the determination of in the range of 0.05–1.60, 0.05–1.40, and 0.05–1.70 µg mL−1 at λ max 585, 608, and 599 nm using reagents I, II, and III, respectively. For more accurate results, Ringbom optimum concentration ranges were found to be 0.10–1.60 µg mL−1. The molar absorptivity, Sandell sensitivity, detection, and quantification limits are also evaluated. The interfering ions and their tolerance limits have been studied. The method was successfully applied to the determination of uranium from standard ores, geological samples, and synthetic matrices.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"52 1","pages":"637 - 648"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89041986","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 Mass and energy spectra of native silver minerals from ore deposit Ducat were studied with the Cameca ims-4f ion microprobe. SIMS depth profiles of 107Ag+ and 109Ag+ secondary ions and 109Ag+/107Ag+ ratio were measured. The change of this ratio in studied minerals and difference of the shape of energy spectra of 107Ag+ and 109Ag+ secondary ions were found. It was revealed that these parameters depend on temperature conditions of minerals formation. A model explaining the observed effects is discussed.
{"title":"Ion Microprobe Silver Isotopic Analysis in Native Silver","authors":"P. Didenko","doi":"10.1081/TMA-120017887","DOIUrl":"https://doi.org/10.1081/TMA-120017887","url":null,"abstract":"Abstract Mass and energy spectra of native silver minerals from ore deposit Ducat were studied with the Cameca ims-4f ion microprobe. SIMS depth profiles of 107Ag+ and 109Ag+ secondary ions and 109Ag+/107Ag+ ratio were measured. The change of this ratio in studied minerals and difference of the shape of energy spectra of 107Ag+ and 109Ag+ secondary ions were found. It was revealed that these parameters depend on temperature conditions of minerals formation. A model explaining the observed effects is discussed.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"55 1","pages":"1 - 11"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79829215","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 the same specimen of scleractinian Fungia fungites L. coral skeleton performed by means of both X- and γ-ray computer axial tomography has revealed several features such as annual growth rings, gastrovascular cavity or sclerosepta to sixths order and more. The apparent thickens of scleorosepta varied between 0.1 and 0.19 mm while the number of growth rings allows us to estimate the average annual growth ratio to about 8 mm/y. Although X-ray computer axial tomography images appear to be of a better quality, no significant differences concerning sensitivity or spatial resolution could be noticed between the two categories of tomographs.
{"title":"X- and γ-Ray CAT Investigation of Fungia fungites L. (Cnidaria, Scleractinia) Coral Skeleton","authors":"O. Duliu, F. Preoteasa, C. Rizescu, G. Georgescu","doi":"10.1081/TMA-120023065","DOIUrl":"https://doi.org/10.1081/TMA-120023065","url":null,"abstract":"Abstract A comparative investigation of the same specimen of scleractinian Fungia fungites L. coral skeleton performed by means of both X- and γ-ray computer axial tomography has revealed several features such as annual growth rings, gastrovascular cavity or sclerosepta to sixths order and more. The apparent thickens of scleorosepta varied between 0.1 and 0.19 mm while the number of growth rings allows us to estimate the average annual growth ratio to about 8 mm/y. Although X-ray computer axial tomography images appear to be of a better quality, no significant differences concerning sensitivity or spatial resolution could be noticed between the two categories of tomographs.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"10 1","pages":"493 - 500"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82466470","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 Surface silica was modified with 3-aminopropyltriethoxysilane [(C2H5O)3-Si(CH2)3NH2] to get amino-modified silica. Surface characteristics and surface area of the silica-gel before and after chemical modification were determined by elemental and surface area analysis. Silica-gel modified with 3-aminopropyltriethoxysilane has been developed for the preconcentration of cobalt and nickel prior to their determination by graphite furnace atomic absorption spectrometry. Batch and column methods were used for the separation and concentration of cobalt and nickel. The experimental parameters, such as the effect of pH of the sample, shaking time in batch technique, flow rate of the eluent and the amount of silica, on retention and elution have been investigated. Cobalt and nickel were successfully recovered from brine (up to 1% NaCl) and sea-water samples.
{"title":"Atomic Absorption Spectrometric Determination of Cobalt and Nickel After Preconcentration by the Application of Chelate Adsorption on Amino-Modified Silica-Gel","authors":"Ö. Göçer Sağlam, Ü. Köklü","doi":"10.1081/TMA-120020260","DOIUrl":"https://doi.org/10.1081/TMA-120020260","url":null,"abstract":"Abstract Surface silica was modified with 3-aminopropyltriethoxysilane [(C2H5O)3-Si(CH2)3NH2] to get amino-modified silica. Surface characteristics and surface area of the silica-gel before and after chemical modification were determined by elemental and surface area analysis. Silica-gel modified with 3-aminopropyltriethoxysilane has been developed for the preconcentration of cobalt and nickel prior to their determination by graphite furnace atomic absorption spectrometry. Batch and column methods were used for the separation and concentration of cobalt and nickel. The experimental parameters, such as the effect of pH of the sample, shaking time in batch technique, flow rate of the eluent and the amount of silica, on retention and elution have been investigated. Cobalt and nickel were successfully recovered from brine (up to 1% NaCl) and sea-water samples.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"10 1","pages":"249 - 257"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88316232","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}
E. Khramova, K. P. Koutzenogij, G. A. Koval’skaya, O. Chankina
Abstract This paper presents new data on the content of the chemical elements in Pentaphylloides fruticosa (L.) O. Schwarz introduced into forest-steppe zone of West Siberia. Synchrotron radiation X-ray-fluorescence analysis (SRXFR) was performed for the plants of different ecotypes. The correlation between the level of accumulation of the elements in the plants and the conditions of their habitat has been established.
{"title":"Trace Elements in Different Pentaphylloides fruticosa Ecotypes","authors":"E. Khramova, K. P. Koutzenogij, G. A. Koval’skaya, O. Chankina","doi":"10.1081/TMA-120017905","DOIUrl":"https://doi.org/10.1081/TMA-120017905","url":null,"abstract":"Abstract This paper presents new data on the content of the chemical elements in Pentaphylloides fruticosa (L.) O. Schwarz introduced into forest-steppe zone of West Siberia. Synchrotron radiation X-ray-fluorescence analysis (SRXFR) was performed for the plants of different ecotypes. The correlation between the level of accumulation of the elements in the plants and the conditions of their habitat has been established.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"55 1","pages":"133 - 145"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83772243","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 differential cross-sections of L X-ray induced in In, Sn, Sb, and Te have been measured at different angles from 94° to 170° at intervals of 9°. Measurement have been performed with a Si(Li) detector using 5.96 keV photons as the excitation source. It is seen from the results concerning heavy elements that L α peaks show anisotropic emissionn while L β and L γ peaks are emitted isotropically.
{"title":"Angular Dependence of L X-Ray Differential Cross-Section for In, Sn, Sb, and Te at 5.96 keV","authors":"L. Demir, M. Sahin, Y. Sahin","doi":"10.1081/TMA-120025810","DOIUrl":"https://doi.org/10.1081/TMA-120025810","url":null,"abstract":"Abstract The differential cross-sections of L X-ray induced in In, Sn, Sb, and Te have been measured at different angles from 94° to 170° at intervals of 9°. Measurement have been performed with a Si(Li) detector using 5.96 keV photons as the excitation source. It is seen from the results concerning heavy elements that L α peaks show anisotropic emissionn while L β and L γ peaks are emitted isotropically.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"31 1","pages":"593 - 599"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88671900","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}
V. Orešcanin, K. Nad, L. Kukec, A. Gajski, D. Sudac, V. Valković
Abstract A system for waste water cleaning using activated red mud is described in this paper. This system was originally developed for heavy metals and turbidity removal from the waste water generated by pressure washing of the boats coated with antifouling paints. The major parts of the system are described. After the treatment clear water can be discharged directly into the sea and the remaining waste mud with high amount of Cu, Zn, and Pb is filtered through the filter bag and stored. It is possible to carry out five cycles with the same dose of coagulant. Untreated water and sediment analysis was done and concentrations of heavy metals in the treated water are lower than the allowed concentrations prescribed for the technological waste water that could be discharged into the environment.
{"title":"Trace Element Analysis of Water and Sediment Before/After Passing a Waste Water Treatment Plant","authors":"V. Orešcanin, K. Nad, L. Kukec, A. Gajski, D. Sudac, V. Valković","doi":"10.1081/TMA-120020266","DOIUrl":"https://doi.org/10.1081/TMA-120020266","url":null,"abstract":"Abstract A system for waste water cleaning using activated red mud is described in this paper. This system was originally developed for heavy metals and turbidity removal from the waste water generated by pressure washing of the boats coated with antifouling paints. The major parts of the system are described. After the treatment clear water can be discharged directly into the sea and the remaining waste mud with high amount of Cu, Zn, and Pb is filtered through the filter bag and stored. It is possible to carry out five cycles with the same dose of coagulant. Untreated water and sediment analysis was done and concentrations of heavy metals in the treated water are lower than the allowed concentrations prescribed for the technological waste water that could be discharged into the environment.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"58 1","pages":"327 - 336"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91028349","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 rapid, selective, and accurate method, based on derivative spectra is proposed for the quantification of thioridazine hydrochloride in the presence of its main degradation product—thioridazine sulphoxide, and vice versa. The determination of thioridazine hydrochloride was made using the second order of derivative (Δλ = 22 nm, third polynomial degree) at 280 nm, while the determination of its sulphoxide is possible by applying the first order derivative spectra (Δλ = 22 nm, second polynomial degree) based on measurements of derivative height at 312 nm. The calibration graphs were linear up to 30 and 50 µg/mL for thioridazine and its sulphoxide, respectively. The limits of detection were 2.91 and 0.77 µg/mL. The elaborated method was applied successfully for determination of the photostability of thioridazine hydrochloride in aqueous solution and in solid phase.
{"title":"UV Derivative Spectrophotometric Study of the Photochemical Degradation of Thioridazine Hydrochloride","authors":"J. Karpińska, M. Sokół","doi":"10.1081/TMA-120025816","DOIUrl":"https://doi.org/10.1081/TMA-120025816","url":null,"abstract":"Abstract A rapid, selective, and accurate method, based on derivative spectra is proposed for the quantification of thioridazine hydrochloride in the presence of its main degradation product—thioridazine sulphoxide, and vice versa. The determination of thioridazine hydrochloride was made using the second order of derivative (Δλ = 22 nm, third polynomial degree) at 280 nm, while the determination of its sulphoxide is possible by applying the first order derivative spectra (Δλ = 22 nm, second polynomial degree) based on measurements of derivative height at 312 nm. The calibration graphs were linear up to 30 and 50 µg/mL for thioridazine and its sulphoxide, respectively. The limits of detection were 2.91 and 0.77 µg/mL. The elaborated method was applied successfully for determination of the photostability of thioridazine hydrochloride in aqueous solution and in solid phase.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"16 1","pages":"649 - 663"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75853087","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}
V. Oreščanin, Anton Katunar, A. Kutle, V. Valković
Abstract The elemental concentrations of nine elements (V, Cr, Mn, Fe, Ni, Cu, Zn, As and Pb) were determined in soil, grape and wine samples taken from the wine producing area of Vrbnik on the island Krk in the northern Adriatic) using the tube excited energy dispersive X-ray fluorescence, EDXRF method. Extensive grape cultivation in Vrbnicko polje through the years approximately doubled the Cu content in the soil from this area compared to the background level determined on Krk. Most of this total Cu is exchangeable and thus available to plants. The concentrations of all other elements are similar to those found in the Krk soil. Canonical analysis showed that the main source of heavy metals in grape was absorption from the soil. Statistically significant differences in elemental composition between red and white wine were found. All elements showed greater concentrations in red grape. In spite of the elevated Cu level in the soil, the content of this metal in wine was much lower than the allowed value.
{"title":"Heavy Metals in Soil, Grape, and Wine","authors":"V. Oreščanin, Anton Katunar, A. Kutle, V. Valković","doi":"10.1081/TMA-120017912","DOIUrl":"https://doi.org/10.1081/TMA-120017912","url":null,"abstract":"Abstract The elemental concentrations of nine elements (V, Cr, Mn, Fe, Ni, Cu, Zn, As and Pb) were determined in soil, grape and wine samples taken from the wine producing area of Vrbnik on the island Krk in the northern Adriatic) using the tube excited energy dispersive X-ray fluorescence, EDXRF method. Extensive grape cultivation in Vrbnicko polje through the years approximately doubled the Cu content in the soil from this area compared to the background level determined on Krk. Most of this total Cu is exchangeable and thus available to plants. The concentrations of all other elements are similar to those found in the Krk soil. Canonical analysis showed that the main source of heavy metals in grape was absorption from the soil. Statistically significant differences in elemental composition between red and white wine were found. All elements showed greater concentrations in red grape. In spite of the elevated Cu level in the soil, the content of this metal in wine was much lower than the allowed value.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"23 1","pages":"171 - 180"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77110571","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 study comprised several co-investigations, each of which formed an original contribution to bilirubin research. Variation in the bioanalytical concentration of the unconjugated specimen and its reversion to other products was examined in each case. The contributions of the different components of the study are broadly summarized as follows: (i) photolysis by sunlight and phototherapy illumination; (ii) the effect of ionizing radiation; (iii) solvent effects and chromatographic studies; (iv) kinetic studies; (v) thermal and chemical effects. Initially, in vitro studies in dilute aqueous NaOH compared the efficiency of sunlight with illumination from a phototherapy unit. The data indicated that at comparable light intensities the phototherapy unit was as effective as sunlight in reducing the bilirubin levels to less than 10% of its original value. This work was extended by subjecting dilute non-aqueous solutions (chloroform) of bilirubin to 137Cs gamma irradiation. It was found that the ionizing radiation caused the bilirubin levels to decrease progressively with increased dose, which led to the formation of biliverdin. When the solvent was changed to deuterated chloroform, biliverdin was observed as a product of the chemical reaction between the solvent and bilirubin. Isolation of the components of the reaction mixture was done by adsorption chromatography. The separated fractions were confirmed spectrophotometrically. A more refined separation was accomplished in a preliminary study under conditions of reverse-phase HPLC, implementing isocratic elution with a solvent composition of 5:95 (v/v) CH3COOH and CH3OH. This produced capacity factors of 3.2 and 6.5 for biliverdin and bilirubin, respectively, for an optimum flow rate of 1 mL/min. The kinetics involving the CDCl3 reaction and the photochemical reaction in sunlight were subsequently examined, and respective rate constants of 0.17 s−1 and 0.15 s−1 were attained. The temperature dependence of the conversion of bilirubin (in aqueous NaOH) to biliverdin revealed that a considerable drop in the bilirubin concentrations was encountered with progressive increases in temperature in the range 25–68°C. This led to improved yields of biliverdin. It was further observed that the application of temperature in the presence of a CuSO4 spike intensified the phenomenon. The scope of our research is discussed.
{"title":"Bioanalysis of Bilirubin: State of Our Art and Future Developments (Review Article)","authors":"A. Pillay, F. Salih, A. Al-Hamdi, S. Al-Kindy","doi":"10.1081/TMA-120020263","DOIUrl":"https://doi.org/10.1081/TMA-120020263","url":null,"abstract":"Abstract The study comprised several co-investigations, each of which formed an original contribution to bilirubin research. Variation in the bioanalytical concentration of the unconjugated specimen and its reversion to other products was examined in each case. The contributions of the different components of the study are broadly summarized as follows: (i) photolysis by sunlight and phototherapy illumination; (ii) the effect of ionizing radiation; (iii) solvent effects and chromatographic studies; (iv) kinetic studies; (v) thermal and chemical effects. Initially, in vitro studies in dilute aqueous NaOH compared the efficiency of sunlight with illumination from a phototherapy unit. The data indicated that at comparable light intensities the phototherapy unit was as effective as sunlight in reducing the bilirubin levels to less than 10% of its original value. This work was extended by subjecting dilute non-aqueous solutions (chloroform) of bilirubin to 137Cs gamma irradiation. It was found that the ionizing radiation caused the bilirubin levels to decrease progressively with increased dose, which led to the formation of biliverdin. When the solvent was changed to deuterated chloroform, biliverdin was observed as a product of the chemical reaction between the solvent and bilirubin. Isolation of the components of the reaction mixture was done by adsorption chromatography. The separated fractions were confirmed spectrophotometrically. A more refined separation was accomplished in a preliminary study under conditions of reverse-phase HPLC, implementing isocratic elution with a solvent composition of 5:95 (v/v) CH3COOH and CH3OH. This produced capacity factors of 3.2 and 6.5 for biliverdin and bilirubin, respectively, for an optimum flow rate of 1 mL/min. The kinetics involving the CDCl3 reaction and the photochemical reaction in sunlight were subsequently examined, and respective rate constants of 0.17 s−1 and 0.15 s−1 were attained. The temperature dependence of the conversion of bilirubin (in aqueous NaOH) to biliverdin revealed that a considerable drop in the bilirubin concentrations was encountered with progressive increases in temperature in the range 25–68°C. This led to improved yields of biliverdin. It was further observed that the application of temperature in the presence of a CuSO4 spike intensified the phenomenon. The scope of our research is discussed.","PeriodicalId":17525,"journal":{"name":"Journal of Trace and Microprobe Techniques","volume":"68 1","pages":"295 - 310"},"PeriodicalIF":0.0,"publicationDate":"2003-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73785157","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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