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1.
Anal Chim Acta ; 1104: 28-37, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32106954

RESUMO

A new analytical method is proposed for the determination of deuterium (D) by ICP-MS. The method is based on the use of the signal from hydrogen-containing polyatomic ions formed in the inductively coupled plasma. Prior to analytical experiments, a theoretical study was performed to assess the concentration of polyatomic species present in an equilibrium Ar-O-D-H plasma, as a function of temperature and stoichiometric composition. It was established that the highest sensitivity and linearity measurement of D concentration in a wide range can be achieved by monitoring the ions of D2 and ArD, at masses 4 and 42, respectively. Results of the calculations are in good agreement with the experiments. Signal stability, spectral interferences, as well as the effect of plasma parameters were also assessed. Under optimized conditions, the limit of detection (LOD) was found to be 3 ppm atom fraction for deuterium when measured as ArD (in calcium and potassium free water), or 78 ppm when measured as D2. The achieved LOD values and the 4 to 5 orders of magnitude dynamic range easily allow the measurement of deuterium concentrations at around or above the natural level, up to nearly 100% (or 1 Mio ppm) in a standard quadrupole ICP-MS instrument. An even better performance is expected from the method in high resolution ICP-MS instruments equipped with low dead volume sample introduction systems.

2.
Appl Spectrosc ; 68(7): 789-93, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25014845

RESUMO

The present study describes the development of an analytical method for the determination of cesium in biological fluid samples (human urine and blood samples) by laser-induced breakdown spectroscopy (LIBS). The developed method is based on sample presentation by liquid-to-solid conversion, enhancing the emission signal by drying the liquid into small "pockets" created in a metal support (zinc plate), and allows the analysis to be carried out on as little as 1 µL of sample volume, in a closed sample cell. Absolute detection limits on the Cs I 852.1 nm spectral line were calculated by the IUPAC 3σ method to be 6 ng in the urine sample and 27 ng in the blood serum sample. It is estimated that LIBS may be used to detect highly elevated concentration levels of Cs in fluid samples taken from people potentially exposed to surges of Cs from non-natural sources.


Assuntos
Césio/análise , Monitoramento Ambiental/métodos , Lasers , Espectrofotometria Atômica/métodos , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Calibragem , Césio/sangue , Césio/urina , Radioisótopos de Césio/análise , Cloretos/análise , Monitoramento Ambiental/instrumentação , Desenho de Equipamento , Humanos , Plasma , Liberação Nociva de Radioativos , Poluentes Radioativos/análise , Padrões de Referência , Gestão da Segurança/métodos , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodos , Espectrofotometria Atômica/instrumentação , Urinálise/instrumentação , Urinálise/métodos , Zinco
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