The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform
Katsumi Yoshida - One of the best experts on this subject based on the ideXlab platform.
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excretion of triethyllead diethyllead and inorganic lead in rabbits after injection of triethyl neopentoxy lead
Industrial Health, 1998Co-Authors: Fumio Arai, Hiroshi Yamauchi, Keiko Chiba, Katsumi YoshidaAbstract:Triethyl neopentoxy lead (TEneoPOL: (C2H5)3Pb [OCH2C(CH3)3] liquid) was administered to rabbits in a single dose of 10 mg/kg body weight (5.4 mg Pb/kg body weight), and the urinary and fecal excretions of lead were measured to determine the fate of this triethyllead derivative. About 4% of the administered amount of was excreted into the urine during the 7 days after the injection; and about 68%, into the feces. In other words, the fecal excretion of total lead was about 17 times as great as the urinary excretion. About 85% of the urinary excretion of total lead was composed of diethyllead (Et2Pb2+), and about 92% of the fecal excretion consisted of inorganic lead (Pb2+). The major chemical species of lead excreted in the urine was Et2Pb2+, while the major species excreted in the feces was Pb2+. These results were similar to those of administration of Tetraethyllead (Et4Pb) to rabbits. One of the 7 rabbits died on the day following the injection, and TEneoPOL, a triethyllead derivative, proved to be no less toxic than Et4Pb. However, this compound is immediately hydrolyzed by the ambient moisture to form a white solid compound, so that it is not accompanied by as great a risk of airway exposure as Et4Pb.
Adam Hulanicki - One of the best experts on this subject based on the ideXlab platform.
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organic palladium and palladium magnesium chemical modifiers in direct determination of lead in fractions from distillation of crude oil by electrothermal atomic absorption analysis
Spectrochimica Acta Part B: Atomic Spectroscopy, 1999Co-Authors: Zofia Kowalewska, Ewa Bulska, Adam HulanickiAbstract:Abstract Platinum reforming catalysts are easily poisoned by increased levels of lead, therefore a sensitive atomic absorption spectrometric procedure for lead determination in fractions from crude oil distillation was developed. Lead was present in organic form in the samples analysed therefore the behaviour of various lead compounds (Pb-alkylarylsulphonate, Pb-4-cyclohexanobutyrate, Tetraethyllead, Pb in fuel oil) was studied. The best procedure for the determination of lead in different petroleum products, including those containing asphaltenes includes a pretreatment with iodine and methyltrioctylammonium chloride, followed by the use of an organic Pd-Mg modifier. Under these conditions an effective matrix removal is possible at a pyrolysis temperature up to approximately 1100°C and the behaviour of lead present in different forms is unified. The characteristic mass is 11–12 pg Pb, corresponding to a detection limit of 0.25 ng g−1 for 20 μl sample solution. This can be lowered by multiple injection.
Fumio Arai - One of the best experts on this subject based on the ideXlab platform.
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excretion of triethyllead diethyllead and inorganic lead in rabbits after injection of triethyl neopentoxy lead
Industrial Health, 1998Co-Authors: Fumio Arai, Hiroshi Yamauchi, Keiko Chiba, Katsumi YoshidaAbstract:Triethyl neopentoxy lead (TEneoPOL: (C2H5)3Pb [OCH2C(CH3)3] liquid) was administered to rabbits in a single dose of 10 mg/kg body weight (5.4 mg Pb/kg body weight), and the urinary and fecal excretions of lead were measured to determine the fate of this triethyllead derivative. About 4% of the administered amount of was excreted into the urine during the 7 days after the injection; and about 68%, into the feces. In other words, the fecal excretion of total lead was about 17 times as great as the urinary excretion. About 85% of the urinary excretion of total lead was composed of diethyllead (Et2Pb2+), and about 92% of the fecal excretion consisted of inorganic lead (Pb2+). The major chemical species of lead excreted in the urine was Et2Pb2+, while the major species excreted in the feces was Pb2+. These results were similar to those of administration of Tetraethyllead (Et4Pb) to rabbits. One of the 7 rabbits died on the day following the injection, and TEneoPOL, a triethyllead derivative, proved to be no less toxic than Et4Pb. However, this compound is immediately hydrolyzed by the ambient moisture to form a white solid compound, so that it is not accompanied by as great a risk of airway exposure as Et4Pb.
Zofia Kowalewska - One of the best experts on this subject based on the ideXlab platform.
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organic palladium and palladium magnesium chemical modifiers in direct determination of lead in fractions from distillation of crude oil by electrothermal atomic absorption analysis
Spectrochimica Acta Part B: Atomic Spectroscopy, 1999Co-Authors: Zofia Kowalewska, Ewa Bulska, Adam HulanickiAbstract:Abstract Platinum reforming catalysts are easily poisoned by increased levels of lead, therefore a sensitive atomic absorption spectrometric procedure for lead determination in fractions from crude oil distillation was developed. Lead was present in organic form in the samples analysed therefore the behaviour of various lead compounds (Pb-alkylarylsulphonate, Pb-4-cyclohexanobutyrate, Tetraethyllead, Pb in fuel oil) was studied. The best procedure for the determination of lead in different petroleum products, including those containing asphaltenes includes a pretreatment with iodine and methyltrioctylammonium chloride, followed by the use of an organic Pd-Mg modifier. Under these conditions an effective matrix removal is possible at a pyrolysis temperature up to approximately 1100°C and the behaviour of lead present in different forms is unified. The characteristic mass is 11–12 pg Pb, corresponding to a detection limit of 0.25 ng g−1 for 20 μl sample solution. This can be lowered by multiple injection.
Walter Lund - One of the best experts on this subject based on the ideXlab platform.
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microconcentric nebulizer for the coupling of micro liquid chromatography and capillary zone electrophoresis with inductively coupled plasma mass spectrometry
Journal of Analytical Atomic Spectrometry, 1997Co-Authors: Anders Tangen, Roger Trones, Tyge Greibrokk, Walter LundAbstract:A concentric nebulizer designed to deliver less than 10 µl min -1 directly into an ICP-MS system is described. The influence of the liquid flow rate, the nebulizer gas flow rate and the distance from the nebulizer tip to the plasma was evaluated with regard to sensitivity and precision. The nebulizer was tested at liquid flow rates of 3–7 µl min -1 . Samples of tetramethyllead and Tetraethyllead dissolved in dimethylformamide were used for the evaluation of the nebulizer. The detection limit for Pb ( m =208) with a direct injection system was found to be 0.3 pg (S/N=3) or 5 µg l -1 , based on an injection volume of 60 nl, a liquid flow rate of 5 µl min -1 and a dwell time of 10 ms. The precision was found to be 1.9% ( n =10) based on peak area measurements. The responses of tetramethyllead and Tetraethyllead were not significantly different ( p =0.05). The time needed for one determination was less than 15 s, owing to the quick rinse out of the nebulizer. The nebulizer can be used as part of a direct injection instrumental set-up. An application of the nebulizer to the coupling of packed capillary liquid chromatography with ICP-MS detection is demonstrated.