The Experts below are selected from a list of 1299 Experts worldwide ranked by ideXlab platform
J D Winefordner - One of the best experts on this subject based on the ideXlab platform.
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Electrothermal Atomization laser excited atomic fluorescence spectroscopy for the determination of indium
Applied Spectroscopy, 1998Co-Authors: R Q Aucelio, B W Smith, J D WinefordnerAbstract:A dye laser pumped by a high-repetition-rate copper vapor laser was used as the excitation source to determine indium at parts-pertrillion level by Electrothermal Atomization laser-excited atomic fluorescence spectrometry (ETA-LEAFS). A comparison was made between wall Atomization, in pyrolytic and nonpyrolytic graphite tubes, and platform Atomization. The influence of several chemical modifiers either in solution or precoated in the graphite tube was evaluated. The influence of several acids and NaOH in the analyte solution was also studied. Optimization of the analytical conditions was carried out to achieve the best signal-to-background ratio and consequently an absolute limit of detection of 1 fg. Some possible interferents of the method were evaluated. The method was evaluated by determining indium in blood, urine, soil, and urban dust samples. Recoveries between 99.17 and 109.17% are reported. A precision of 4.1% at the 10 ng g-1 level in water standards was achieved.
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ultratrace determination of platinum in environmental and biological samples by Electrothermal Atomization laser excited atomic fluorescence using a copper vapor laser pumped dye
Journal of Analytical Atomic Spectrometry, 1998Co-Authors: R Q Aucelio, B W Smith, V N Rubin, J D WinefordnerAbstract:A method to determine ultratrace amounts of platinum in biological and environmental samples based on Electrothermal Atomization laser-excited fluorescence spectrometry (ETA–LEAFS) is described. A high repetition rate copper vapor laser was employed as a dye laser pump in order to probe more efficiently the platinum atoms generated in a graphite furnace. The L'vov platform, the Katskov type graphite filter and wall Atomization were evaluated to obtain the best Atomization technique for complex samples. Atomization and ashing temperature studies were performed to obtain the highest signal to noise ratio and/or efficient separation of the analyte from complex matrix components. An absolute limit of detection of 50 fg was achieved based on fluorescence values of aqueous standard solutions. The linear dynamic range was from 1.0 to 250 ng g–1; the 250 ng g–1 was limited by detector saturation. A precision of 4.5% at the 10 ng g–1 level was obtained for water solutions, increasing to 8.0% for complex samples. Recoveries between 100 and 108% were obtained for urine, blood, soil and used auto catalyst pellet samples.
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Electrothermal Atomization laser excited atomic fluorescence spectrometry for direct analysis of germanium in water and blood samples
Analytica Chimica Acta, 1997Co-Authors: R Q Aucelio, B W Smith, V N Rubin, E Becerra, J D WinefordnerAbstract:Abstract Laser-excited atomic fluorescence spectrometry using a copper vapor laser as the excitation source has been used to develop a very sensitive method for direct determination of ultratrace amounts of germanium. For more efficient sample Atomization, a graphite furnace was employed. Two excitation-detection schemes were evaluated. The best conditions for the analysis of germanium in water and blood are described. The effect of matrix modifiers and some possible interferences are reported. Absolute limits of detection of 0.7 pg (3σ) with a precision of 3.5% at the 2 ppb level for water samples and 1.0 pg (3σ) with 8.0% precision at the 2 ppb level for blood samples were achieved with no need for preconcentration.
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ultratrace determination of lead in whole blood using Electrothermal Atomization laser excited atomic fluorescence spectrometry
Analytical Chemistry, 1996Co-Authors: Eugene P Wagner, B W Smith, J D WinefordnerAbstract:Laser-excited atomic fluorescence has been used to detect lead that was Electrothermally atomized from whole blood in a graphite furnace. A 9 kHz repetition rate copper vapor laser pumped dye laser was used to excite the lead at 283.3 nm, and the resulting atomic fluorescence was detected at 405.8 nm. No matrix modification was used other than a 1:21 dilution of the whole blood with high-purity water. Using the atomic fluorescence peak area as the analytical measure and a background correction technique based upon a simultaneous measurement of the transmitted laser intensity, excellent agreement for NIST and& CDC certified whole blood reference samples was obtained with aqueous standards. A limit of detection in blood of 10 fg/mL (100 ag absolute) was achieved.
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determination of mercury in microwave digested soil by laser excited atomic fluorescence spectrometry with Electrothermal Atomization
Talanta, 1994Co-Authors: Stefanie T Pagano, B W Smith, J D WinefordnerAbstract:Abstract A sample digestion procedure was developed which employs microwave heating of soil and sediment in concentrated nitric acid in a high-pressure closed vessel. Complete dissolution of mercury into the sample solution occurs within 5 min at 59 W/vessel without loss of analyte through overpressurization. Laser-excited atomic fluorescence spectrometry with Electrothermal Atomization (LEAFS-ETA) was used as the detection method. The scheme uses a two-step excitation, with λ 1 = 253.7 nm and λ 2 = 435.8 nm. Direct line fluorescence was measured at 546.2 nm. The absolute instrumental limit of detection was 14 fg; 1.4 pg/ml with a 10 μl sample injection. The recoveries of mercury in two spiked samples were 94 and 98%. The SRM 8406 (Mercury in River Sediment) was digested and analyzed for mercury, and the results (58.4 ± 1.8 ng/g) agreed well with the reference value of 60 ng/g. The results obtained by LEAFS-ETA with microwave sample digestion are in good agreement with those found by cold vapor atomic absorption spectrometry with EPA Series Method 245.5 sample digestion, which is one of the most commonly used methods for the determination of mercury in soil.
B W Smith - One of the best experts on this subject based on the ideXlab platform.
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Electrothermal Atomization laser excited atomic fluorescence spectroscopy for the determination of indium
Applied Spectroscopy, 1998Co-Authors: R Q Aucelio, B W Smith, J D WinefordnerAbstract:A dye laser pumped by a high-repetition-rate copper vapor laser was used as the excitation source to determine indium at parts-pertrillion level by Electrothermal Atomization laser-excited atomic fluorescence spectrometry (ETA-LEAFS). A comparison was made between wall Atomization, in pyrolytic and nonpyrolytic graphite tubes, and platform Atomization. The influence of several chemical modifiers either in solution or precoated in the graphite tube was evaluated. The influence of several acids and NaOH in the analyte solution was also studied. Optimization of the analytical conditions was carried out to achieve the best signal-to-background ratio and consequently an absolute limit of detection of 1 fg. Some possible interferents of the method were evaluated. The method was evaluated by determining indium in blood, urine, soil, and urban dust samples. Recoveries between 99.17 and 109.17% are reported. A precision of 4.1% at the 10 ng g-1 level in water standards was achieved.
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ultratrace determination of platinum in environmental and biological samples by Electrothermal Atomization laser excited atomic fluorescence using a copper vapor laser pumped dye
Journal of Analytical Atomic Spectrometry, 1998Co-Authors: R Q Aucelio, B W Smith, V N Rubin, J D WinefordnerAbstract:A method to determine ultratrace amounts of platinum in biological and environmental samples based on Electrothermal Atomization laser-excited fluorescence spectrometry (ETA–LEAFS) is described. A high repetition rate copper vapor laser was employed as a dye laser pump in order to probe more efficiently the platinum atoms generated in a graphite furnace. The L'vov platform, the Katskov type graphite filter and wall Atomization were evaluated to obtain the best Atomization technique for complex samples. Atomization and ashing temperature studies were performed to obtain the highest signal to noise ratio and/or efficient separation of the analyte from complex matrix components. An absolute limit of detection of 50 fg was achieved based on fluorescence values of aqueous standard solutions. The linear dynamic range was from 1.0 to 250 ng g–1; the 250 ng g–1 was limited by detector saturation. A precision of 4.5% at the 10 ng g–1 level was obtained for water solutions, increasing to 8.0% for complex samples. Recoveries between 100 and 108% were obtained for urine, blood, soil and used auto catalyst pellet samples.
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Electrothermal Atomization laser excited atomic fluorescence spectrometry for direct analysis of germanium in water and blood samples
Analytica Chimica Acta, 1997Co-Authors: R Q Aucelio, B W Smith, V N Rubin, E Becerra, J D WinefordnerAbstract:Abstract Laser-excited atomic fluorescence spectrometry using a copper vapor laser as the excitation source has been used to develop a very sensitive method for direct determination of ultratrace amounts of germanium. For more efficient sample Atomization, a graphite furnace was employed. Two excitation-detection schemes were evaluated. The best conditions for the analysis of germanium in water and blood are described. The effect of matrix modifiers and some possible interferences are reported. Absolute limits of detection of 0.7 pg (3σ) with a precision of 3.5% at the 2 ppb level for water samples and 1.0 pg (3σ) with 8.0% precision at the 2 ppb level for blood samples were achieved with no need for preconcentration.
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ultratrace determination of lead in whole blood using Electrothermal Atomization laser excited atomic fluorescence spectrometry
Analytical Chemistry, 1996Co-Authors: Eugene P Wagner, B W Smith, J D WinefordnerAbstract:Laser-excited atomic fluorescence has been used to detect lead that was Electrothermally atomized from whole blood in a graphite furnace. A 9 kHz repetition rate copper vapor laser pumped dye laser was used to excite the lead at 283.3 nm, and the resulting atomic fluorescence was detected at 405.8 nm. No matrix modification was used other than a 1:21 dilution of the whole blood with high-purity water. Using the atomic fluorescence peak area as the analytical measure and a background correction technique based upon a simultaneous measurement of the transmitted laser intensity, excellent agreement for NIST and& CDC certified whole blood reference samples was obtained with aqueous standards. A limit of detection in blood of 10 fg/mL (100 ag absolute) was achieved.
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determination of mercury in microwave digested soil by laser excited atomic fluorescence spectrometry with Electrothermal Atomization
Talanta, 1994Co-Authors: Stefanie T Pagano, B W Smith, J D WinefordnerAbstract:Abstract A sample digestion procedure was developed which employs microwave heating of soil and sediment in concentrated nitric acid in a high-pressure closed vessel. Complete dissolution of mercury into the sample solution occurs within 5 min at 59 W/vessel without loss of analyte through overpressurization. Laser-excited atomic fluorescence spectrometry with Electrothermal Atomization (LEAFS-ETA) was used as the detection method. The scheme uses a two-step excitation, with λ 1 = 253.7 nm and λ 2 = 435.8 nm. Direct line fluorescence was measured at 546.2 nm. The absolute instrumental limit of detection was 14 fg; 1.4 pg/ml with a 10 μl sample injection. The recoveries of mercury in two spiked samples were 94 and 98%. The SRM 8406 (Mercury in River Sediment) was digested and analyzed for mercury, and the results (58.4 ± 1.8 ng/g) agreed well with the reference value of 60 ng/g. The results obtained by LEAFS-ETA with microwave sample digestion are in good agreement with those found by cold vapor atomic absorption spectrometry with EPA Series Method 245.5 sample digestion, which is one of the most commonly used methods for the determination of mercury in soil.
Philippe Giamarchi - One of the best experts on this subject based on the ideXlab platform.
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imaging time resolved Electrothermal Atomization laser excited atomic fluorescence spectrometry for determination of mercury in seawater
Analytical Chemistry, 2011Co-Authors: Alain Le Bihan, Jeanyves Cabon, Laure Deschamps, Philippe GiamarchiAbstract:In this study, direct determination of mercury at the nanogram per liter level in the complex seawater matrix by imaging time-resolved Electrothermal Atomization laser-excited atomic fluorescence spectrometry (ITR-ETA-LEAFS) is described. In the case of mercury, the use of a nonresonant line for fluorescence detection with only one laser excitation is not possible. For measurements at the 253.652 nm resonant line, scattering phenomena have been minimized by eliminating the simultaneous vaporization of salts and by using temporal resolution and the imaging mode of the camera. Electrothermal conditions (0.1 M oxalic acid as matrix modifier, low Atomization temperature) have been optimized in order to suppress chemical interferences and to obtain a good separation of specific signal and seawater background signal. For ETA-LEAFS, a specific response has been obtained for Hg with the use of time resolution. Moreover, an important improvement of the detection limit has been obtained by selecting, from the furna...
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laser induced fluorescence with an opo system part ii direct determination of lead content in seawater by Electrothermal Atomization laser excited atomic fluorescence eta leaf
Analytical and Bioanalytical Chemistry, 2003Co-Authors: Le A Bihan, Y Lijour, Philippe Giamarchi, L Bureldeschamps, L StephanAbstract:Fluorescence was induced by coupling a laser with an optical parametric oscillator (OPO) to develop an analytical method for the direct determination of lead content, at ultra-trace level, in seawater by Electrothermal Atomization–laser-excited atomic fluorescence (ETA–LEAF). The optimization of Atomization conditions, laser pulse energy, and mainly temporal parameters allowed us to reach a 3 fg detection limit (0.3 ng L−1) despite the low repetition rate of the device. The expected error on predicted concentrations of lead, at trace levels, in seawater was below 15%.
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direct determination of aluminum content in seawater by Electrothermal Atomization laser excited atomic fluorescence
Spectrochimica Acta Part B: Atomic Spectroscopy, 2003Co-Authors: Le A Bihan, Y Lijour, Philippe Giamarchi, L Bureldeschamps, L StephanAbstract:Abstract The development of an analytical method for the direct determination of ultra trace content of aluminum in seawater by Electrothermal Atomization-laser excited atomic fluorescence (ETA-LEAF) using a pulsed Nd:Yag laser associated with an optical parametric oscillator (OPO) and an intensified CCD (ICCD) camera is described. The good temporal reproducibility of the device and the fairly long lifetime of the selected Al radiation allowed optimization of the temporal parameters in the nanosecond range. After optimizing thermal and optical parameters, this potentiality allowed to reach a 100 fg detection limit (5 ng l−1). The method was developed within a multidisciplinary program involving chemical and physical applications, thereby demonstrating the versatility of the apparatus.
L Stephan - One of the best experts on this subject based on the ideXlab platform.
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laser induced fluorescence with an opo system part ii direct determination of lead content in seawater by Electrothermal Atomization laser excited atomic fluorescence eta leaf
Analytical and Bioanalytical Chemistry, 2003Co-Authors: Le A Bihan, Y Lijour, Philippe Giamarchi, L Bureldeschamps, L StephanAbstract:Fluorescence was induced by coupling a laser with an optical parametric oscillator (OPO) to develop an analytical method for the direct determination of lead content, at ultra-trace level, in seawater by Electrothermal Atomization–laser-excited atomic fluorescence (ETA–LEAF). The optimization of Atomization conditions, laser pulse energy, and mainly temporal parameters allowed us to reach a 3 fg detection limit (0.3 ng L−1) despite the low repetition rate of the device. The expected error on predicted concentrations of lead, at trace levels, in seawater was below 15%.
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direct determination of aluminum content in seawater by Electrothermal Atomization laser excited atomic fluorescence
Spectrochimica Acta Part B: Atomic Spectroscopy, 2003Co-Authors: Le A Bihan, Y Lijour, Philippe Giamarchi, L Bureldeschamps, L StephanAbstract:Abstract The development of an analytical method for the direct determination of ultra trace content of aluminum in seawater by Electrothermal Atomization-laser excited atomic fluorescence (ETA-LEAF) using a pulsed Nd:Yag laser associated with an optical parametric oscillator (OPO) and an intensified CCD (ICCD) camera is described. The good temporal reproducibility of the device and the fairly long lifetime of the selected Al radiation allowed optimization of the temporal parameters in the nanosecond range. After optimizing thermal and optical parameters, this potentiality allowed to reach a 100 fg detection limit (5 ng l−1). The method was developed within a multidisciplinary program involving chemical and physical applications, thereby demonstrating the versatility of the apparatus.
R Q Aucelio - One of the best experts on this subject based on the ideXlab platform.
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Electrothermal Atomization laser excited atomic fluorescence spectroscopy for the determination of indium
Applied Spectroscopy, 1998Co-Authors: R Q Aucelio, B W Smith, J D WinefordnerAbstract:A dye laser pumped by a high-repetition-rate copper vapor laser was used as the excitation source to determine indium at parts-pertrillion level by Electrothermal Atomization laser-excited atomic fluorescence spectrometry (ETA-LEAFS). A comparison was made between wall Atomization, in pyrolytic and nonpyrolytic graphite tubes, and platform Atomization. The influence of several chemical modifiers either in solution or precoated in the graphite tube was evaluated. The influence of several acids and NaOH in the analyte solution was also studied. Optimization of the analytical conditions was carried out to achieve the best signal-to-background ratio and consequently an absolute limit of detection of 1 fg. Some possible interferents of the method were evaluated. The method was evaluated by determining indium in blood, urine, soil, and urban dust samples. Recoveries between 99.17 and 109.17% are reported. A precision of 4.1% at the 10 ng g-1 level in water standards was achieved.
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ultratrace determination of platinum in environmental and biological samples by Electrothermal Atomization laser excited atomic fluorescence using a copper vapor laser pumped dye
Journal of Analytical Atomic Spectrometry, 1998Co-Authors: R Q Aucelio, B W Smith, V N Rubin, J D WinefordnerAbstract:A method to determine ultratrace amounts of platinum in biological and environmental samples based on Electrothermal Atomization laser-excited fluorescence spectrometry (ETA–LEAFS) is described. A high repetition rate copper vapor laser was employed as a dye laser pump in order to probe more efficiently the platinum atoms generated in a graphite furnace. The L'vov platform, the Katskov type graphite filter and wall Atomization were evaluated to obtain the best Atomization technique for complex samples. Atomization and ashing temperature studies were performed to obtain the highest signal to noise ratio and/or efficient separation of the analyte from complex matrix components. An absolute limit of detection of 50 fg was achieved based on fluorescence values of aqueous standard solutions. The linear dynamic range was from 1.0 to 250 ng g–1; the 250 ng g–1 was limited by detector saturation. A precision of 4.5% at the 10 ng g–1 level was obtained for water solutions, increasing to 8.0% for complex samples. Recoveries between 100 and 108% were obtained for urine, blood, soil and used auto catalyst pellet samples.
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Electrothermal Atomization laser excited atomic fluorescence spectrometry for direct analysis of germanium in water and blood samples
Analytica Chimica Acta, 1997Co-Authors: R Q Aucelio, B W Smith, V N Rubin, E Becerra, J D WinefordnerAbstract:Abstract Laser-excited atomic fluorescence spectrometry using a copper vapor laser as the excitation source has been used to develop a very sensitive method for direct determination of ultratrace amounts of germanium. For more efficient sample Atomization, a graphite furnace was employed. Two excitation-detection schemes were evaluated. The best conditions for the analysis of germanium in water and blood are described. The effect of matrix modifiers and some possible interferences are reported. Absolute limits of detection of 0.7 pg (3σ) with a precision of 3.5% at the 2 ppb level for water samples and 1.0 pg (3σ) with 8.0% precision at the 2 ppb level for blood samples were achieved with no need for preconcentration.