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Development and optimization of methods for elemental quantitative analysis of catalysts and polymers through laser ablation-ICP techniquesVillaseñor Milán, Ángela 25 July 2018 (has links)
En la presente Tesis Doctoral la técnica de ablación laser acoplada a ICP-OES/MS ha sido empleada para analizar muestras sólidas, como catalizadores usados en el refinado del petróleo y polímeros. Se han llevado a cabo dos tipos de análisis, un análisis global de las muestras que proporciona información general y un análisis localizado que permite obtener información acerca de la distribución espacial de los elementos de interés en las muestras. Las diferentes variables de la técnica ablación láser son estudiadas con el fin de seleccionar aquellas que conducen una señal alta y estable, así como a un menor grado de fraccionamiento. Este estudio se realiza para cada tipo de muestra, ya que los resultados dependen de la matriz estudiada. Además, en esta Tesis doctoral se desarrolla un método de calibración para llevar a cabo un análisis cuantitativo de las muestras sólidas, basado en la deposición de patrones líquidos sobre la muestra sólida. Este método es conocido como “dried droplet calibration approach” (DDCA), y permite cuantificar elementos presentes en muestras sólidas sin necesidad de usar materiales de referencia sólidos. Este nuevo método de calibración compensa el fraccionamiento elemental y los efectos de matriz, proporcionando resultados exactos y preciosos para muestras complejas tales como vidrios, catalizadores y polímeros.
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[pt] ESTUDO DOS EFEITOS DE TINTURAS DE CABELOS NOS RESULTADOS DO MINERALOGRAMA CAPILAR: UMA ABORDAGEM QUIMIOMÉTRICA / [en] STUDY OF THE EFFECTS OF HAIR DYE ON THE RESULTS OF THE CAPILLARY MINERALOGRAM: A CHEMOMETRIC APPROACHVERONICA LUIZA ESTEVES DOS SANTOS 19 April 2023 (has links)
[pt] O exame de mineralograma capilar fornece as concentrações de
elementos tóxicos e essenciais no cabelo. O uso de produtos capilares, além de
poderem representar uma fonte de exposição, é possível que causem alterações
na composição mineral do cabelo. Neste trabalho, amostras de cabelo natural
foram submetidas a tratamentos com diferentes tinturas e, posteriormente,
analisadas seguindo a metodologia pré-estabelecida para determinação
multielementar por espectrometria de massas com plasma indutivamente
acoplado (ICP-MS). A composição elementar do cabelo humano natural foi
comparada com as determinadas nas mesmas amostras de cabelo submetidas a
tratamentos com diferentes tintas. Utilizando o teste estatístico Kruskal-Wallis,
foi possível identificar diferenças significativas (p < 0,05) para os elementos Na,
K e Mg, cujas concentrações aumentaram (de 100 a 5000x) após o uso das
tinturas permanentes e semipermantes, enquanto para os cabelos que foram
submetidos a tratamentos com corantes naturais isso não foi observado. Alguns
elementos como Al, Fe, P tiveram decréscimo em suas concentrações (de 20 a
40%) após o uso desses tratamentos. Diante disso, foi possível determinar que
alguns elementos são transferidos ou removidos do cabelo após o uso de
determinados produtos, confirmando que tratamentos estéticos podem interferir
nos resultados do exame do mineralograma capilar, devendo ser avaliada a
necessidade da realização do mesmo em pacientes com cabelo tingido ou a
possibilidade de aguardar por, pelo menos, 3 meses sem o uso de tratamentos
permanentes antes da coleta da amostra para realização do exame. / [en] The hair mineral analysis test reports the concentrations of toxics and
essential elements inside the hair structure. The utilization of hair care products,
in addition to being able to represent an exposure source, also can be responsible
for certain changes in the mineral composition of the hair. In present work,
natural hair samples were treated with different dyes and, posteriorly, studied
following the pre-established protocol for multi-element analysis by means of
inductively coupled plasma mass spectrometry (ICP-MS). Hence, the element
compositions of natural human hair after different treatments were compared.
With the help of the Kruskal-Wallis statistical test, it was possible to identify
significant differences (p < 0.05) for the elements, such as Na, K and Mg. Their
concentrations increased from 100 to 5000x after the use of permanent and semipermanent
dyes, while in the case of the hair samples treated with the natural
dye no significant difference was observed. The concentrations of some
elements, such as Al, Fe, P decreased (from 20 to 40%) after the respective
treatments. Therefore, it was established that some elements are transferred or
removed from the hair after the use of certain products, confirming that aesthetic
treatments can interfere the results of the hair mineral analysis test. It reasons
testing in patients with dyed hair or the possibility of waiting for about 3 months
without the use of permanent treatments before sample collection for the
analysis.
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The Toxicity Assessment of Heavy Metals and Their Species in RiceZhang, Julie Zhiling January 2009 (has links)
No description available.
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[pt] CARACTERIZAÇÃO METALOPROTEÔMICA DE BÍLIS DE ELASMOBRÂNQUIOS DO RIO DE JANEIRO E AVALIAÇÃO DO SEU POTENCIAL COMO BIOMARCADOR DE CONTAMINAÇÃO AMBIENTAL / [en] METALLOPROTEOMIC CHARACTERIZATION OF ELASMOBRANCH BILE FROM RIO DE JANEIRO AND EVALUATION OF ITS POTENTIAL AS AN ENVIRONMENTAL CONTAMINATION BIOMARKERREGINA FONSECA DE ALMEIDA 13 May 2024 (has links)
[pt] Os metais e metaloides representam um problema global pela possibilidade de
bioacumulação e biomagnificação ao longo de teias tróficas aquáticas. Os
elasmobrânquios, grupo taxonômico que inclui as raias e tubarões, são vulneráveis
à pesca e poluentes químicos. Poucos estudos avaliaram a presença e os efeitos de
metais e metaloides nestes animais e estudos com amostragem não-letal são ainda
escassos. Este estudo avaliou o potencial da bílis como biomarcador de
contaminação recente em três espécies de elasmobrânquios ameaçados capturados
artesanalmente na cidade do Rio de Janeiro, Gymnura altavela, Dasyatis
hypostigma e Pseudobatos horkelii. As concentrações de metais e metaloides
biliares foram determinadas por espectrometria de massa com plasma
indutivamente acoplado (ICP-MS), as metalotioneínas por espectrometria UV-Vis
e as associações entre metais intracelulares e metalotioneínas por cromatografia
líquida de alta eficiência com separação por exclusão de tamanho acoplada a ICP-MS (SEC-HPLC-ICP-MS). No geral, Fe apresentou as maiores concentrações
(máx. 194,8 mg L-1) e Sn as menores (máx. 0,004 mg L-1), quantificado em apenas
cinco indivíduos do total estudado (107). Arsênio e cobre apresentaram maiores
médias (10,9 e 5,2 mg L-1, respectivamente) nas amostras de bílis de raia viola, a
única espécie capturada em Copacabana. Correlações estatísticas entre as
concentrações de metalotioneínas, índices biomorfométricos e concentrações
elementares nas frações das amostras de bílis indicam contaminação ambiental e
potenciais efeitos sub letais no desenvolvimento e reprodução desses animais. Os
resultados obtidos por SECHPLC-ICP-MS indicam diferenças metabólicas nas
rotas de destoxificação das diferentes espécies. Conclui-se que o uso de bílis de
elasmobrânquios é uma alternativa eficaz e que permite a amostragem não-letal
para monitorar a contaminação ambiental recente por metais e metaloides. / [en] Metals and metalloids can represent a significant global issue, due to the potential
for high bioaccumulation and biomagnification along aquatic food webs.
Elasmobranchs, a taxonomic group that includes rays and sharks, are highly
vulnerable to fishing activities and chemical pollutants. Few studies have
investigated the presence and impacts of metals and metalloids in these animals,
and studies with non-lethal sampling methods are still scarce. This study evaluated
the potential of bile as a biomarker of recent contamination in three threatened
species of elasmobranchs artisanally captured in the city of Rio de Janeiro,
Gymnura altavela, Dasyatis hypostigma, and Pseudobatos horkelii. Biliary metal
and metalloid concentrations were determined by Inductively Coupled Plasma
Mass Spectrometry (ICP-MS), metallothioneins by UV-Vis spectrometry, and
associations between intracellular metals and metallothioneins were investigated by
Size Exclusion-High-Performance Liquid Chromatography coupled to ICP-MS
(SEC-HPLC-ICP-MS). Overall, Fe presented the highest concentrations (0.7 more or less 0.1 mg L-1) and Sn the lowest (max. 0.004 mg L-1), quantified in only five individuals
of the total studied (107). Arsenic and copper showed higher averages (10.9 and 5.2
mg L-1, respectively) in bile samples from Brazilian guitarfish, the only species
caught in Copacabana. Statistical correlations among metallothionein
concentrations, biometric indices, and elemental concentrations in bile fractions
suggest environmental contamination and potential sublethal effects on the
development and reproduction of these animals. Results obtained from SEC-HPLC-ICP-MS indicate metabolic differences in detoxification pathways among the
various species. In conclusion, the utilization of elasmobranch bile is an effective
alternative that allows non-lethal sampling for monitoring recent environmental
contamination by metals and metalloids.
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Development and Application of IDMS Based Procedure for total Sulphur in Copper Metals and Its AlloysPhukphatthanachai, Pranee 05 April 2019 (has links)
Bei der Schwefelquantifizierung in Kupfer und anderen reinen Metallen zeigte sich in der Vergangenheit eine mangelnde SI-Rückführung und zusätzlich inkonsistente Ergebnisse, wenn verschiedene Methoden verglichen wurden. Um diesen Mangel zu beheben ist ein Referenzverfahren erforderlich, welches SI-rückführbare Werte mit einem zuverlässigen Unsicherheitsbudget ermöglicht. In dieser Studie wurde ein entsprechendes Referenzverfahren zur Quantifizierung von Gesamtschwefel in Kupfer basierend auf der induktiv gekoppelten Plasma-Massenspektrometrie und der Isotopenverdünnungsanalyse (ICP-IDMS) entwickelt.
Um diese Probleme zu lösen wurde mit Hilfe der Ionenaustauschchromatographie ein Schwefel-Matrix-Trennverfahren entwickelt. Dieses Trennverfahren wurde mit ICP-IDMS kombiniert, um Schwierigkeiten mit der Kalibrierung zu lösen und fehlende metrologische Konzepte einzuführen. So wurden die in diesem Projekt erzielten IDMS-Messwerte für die Kalibrierung von GDMS und LA-ICP-MS verwendet, beides Verfahren die im industriellen Einsatz üblich sind. Dadurch konnten mit beiden Routineverfahren zuverlässige Ergebnisse erzeilt warden, die zudem auf SI rückführbar sind.
Darüber hinaus wurde ein auf der LA-ICP-IDMS basierendes Verfahren entwickelt, um den Probenvorbereitungsschritt von ICP-IDMS mit Schwefel-Matrix-Trennung zu reduzieren. Die Vorteile dieser Methode sind ein geringerer Arbeits- und Zeitaufwand, die SI- Rückführung der Messergebnisse und eine für LA-ICP-MS vergleichsweise hohe Genauigkeit. Die Schlüsselrolle hierbei spielte der innovative Einsatz von Polyethylenfritten als Trägermaterial der aufgelösten Probe. Dadurch war die Quantifizierung von Schwefel in Kupferproben mittels LA-ICP-IDMS möglich. Die wesentlichen Parameter wie Absorptionseffizienz der Fritten und Matrixeffekt wurden untersucht. Das entwickelte Verfahren konnte mit Hilfe der ICP-IDMS vollständig validiert werden. / Sulphur quantification in copper and other pure metals in the past revealed a lack of SI-traceability and also showed inconsistent results, when different methods are compared. Therefore, a reference procedure is required to enable SI-traceable measurement results accompanied by a sound uncertainty budget. In this study, such a procedure was developed for the quantification of total sulphur in copper using inductively coupled plasma-isotope dilution mass spectrometry (ICP-IDMS).
For solving these problems ion exchange chromatography was applied, and a sulphur-matrix separation procedure was developed. This procedure was combined with ICP-IDMS to solve difficulties with the calibration and to realize metrological concepts.
An application of the IDMS procedure was realized by using the measurement results of specific copper samples values for calibrating glow discharge mass spectrometry (GDMS) and laser ablation ICP-MS (LA-ICP-MS). Both techniques are considered routine techniques. Thus, they could provide reliable results which are traceable to the SI.
Additionally, a procedure based on LA-ICP-IDMS was developed to significantly reduce the sample preparation step of ICP-IDMS with sulphur-matrix separation. This procedure is less laborious and the measurement results are still SI traceable and offer a comparatively high accuracy for LA-ICP-MS. Key for this development was the innovative application of polyethylene frits as support material for the dissolved sample. Thus, the quantification of sulphur in copper samples by LA-ICP-IDMS could be realized. The essential parameters are investigated such as the absorption efficiency of the frit and matrix effects. The developed procedure was fully validated by means of the ICP-IDMS results.
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Avaliação do uso da cela de reação dinâmica em espectrometria de massas com plasma acoplado indutivamente (DRC-ICP-MS) para determinação de elementos químicos em sangue / Evaluation of the use of dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) for determination of elements in whole bloodBatista, Bruno Lemos 30 April 2009 (has links)
A espectrometria de massas com plasma acoplado indutivamente com simples quadrupolo (q-ICP-MS) e cela de reação dinâmica (DRC-ICP-MS) foi avaliada para determinação seqüencial de Al, As, Cd, Co, Cu, Cr, Mn, Mo, Pb, Pt, Sb, Se, Sn, Te, Tl, V e Zn em sangue. Para as análises, amostras de sangue (200 µL) foram diluídas 1:50 em uma solução contendo 0,01% v/v Triton® X-100 e 0,5% v/v de ácido nítrico. As calibrações foram realizadas com ajuste de matriz, utilizando sangue ovino. Como gás de reação utilizou-se a NH3. O uso do DRC foi fundamental para a determinação de Cr e V. A escolha da melhor vazão do gás e a otimização do parâmetro de rejeição (RPq) foram estudadas utilizando sangue base ovino ou uma solução de matriz sintética (SMS), de acordo com a concentração do analito no sangue base. Os limites de detecção (3s/coeficiente angular) para determinação de 27Al, 75As, 111Cd, 59Co, 63Cu, 55Mn, 98Mo, 208Pb, 195Pt, 123Sb, 82Se, 120Sn, 130Te, 205Tl e 66Zn em sangue por q-ICP-MS foram 0,223; 0,014; 0,003; 0,011; 0,304; 0,009; 0,009; 0,003; 0,001; 0,005; 0,264; 0,006; 0,010; 0,001; 0,834 µg L-1, respectivamente, e para determinação de 52Cr e 51V em sangue por DRC-ICP-MS utilizando o gás de reação amônia os limites de detecção foram de 0,007 e 0,006 µg L-1. Para a determinação de 27Al, 63Cu, 65Cu, 64Zn e 66Zn em sangue por q-ICP-MS através da calibração com ajuste de matriz com SMS os limites de detecção foram 0,083; 0,090; 0,055; 0,281; 0,306 µg L-1, respectivamente. A validação do método foi realizada por meio da análise de materiais de referência do INSP-Canadá, NYSDOH-EUA e Seronorm-Noruega. / The use of inductively coupled plasma mass spectrometry with quadrupole (q-ICP-MS) and dynamic reaction cell (DRC-ICP-MS) was evaluated for sequential determination of Al, As, Cd, Co, Cu, Cr, Mn, Mo, Pb, Pt, Sb, Se, Sn, Te, Tl, V and Zn in whole blood by q-ICP-MS or DRC-ICP-MS methods. Prior to analysis, sample (200 µL) were diluted 1:50 v/v in a solution containing 0.01% v/v Triton® X-100 and 0.5% v/v nitric acid. For all elements, except Cr and V, the instrument was operated in q-ICP-MS mode. The use of DRC was only mandatory for Cr and V. NH3 was evaluated as the reaction gas. Selection of best flow rate of reaction gas and optimization of the quadrupole dynamic bandpass rejection parameter (RPq) were carried out, using base whole blood or synthetic matrix solution (SMS), in according with element base blood concentration. Method detection limits (3s/slope) for 27Al, 75As, 111Cd, 59Co, 63Cu, 55Mn, 98Mo, 208Pb, 195Pt, 123Sb, 82Se, 120Sn, 130Te, 205Tl and 66Zn determination in whole blood by q-ICP-MS against matrix matching calibration (base blood) were 0.223; 0.014; 0.003; 0.011; 0.304; 0.009; 0.009; 0.003; 0.001; 0.005; 0.264; 0.006; 0.010; 0.001; 0.834 µg L-1, respectively, and for 52Cr and 51V determination in whole blood by DRC-ICP-MS the detection limits were 0.007 e 0.006 µg L-1. For 27Al, 63Cu, 65Cu, 64Zn and 66Zn determination by q-ICP-MS through matrix matching calibration with SMS the detection limits were 0.083; 0.090; 0.055; 0.281; 0.306 µg L-1, respectively. Method validation was accomplished by the analysis of reference materials from INSP-Canada, NYSDOH-USA, Seronorm-Norway.
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Fundamental Studies on Direct Injection Nebulisers for Sample Introduction in ICP Spectrometry : Aerosol Properties, ICP Characteristics and Analytical PerformanceGoitom Asfaha, Daniel January 2006 (has links)
<p>The performance of different types of nebulisers: Vulkan direct injection nebuliser (Vulkan DIN), direct injection high efficiency nebuliser (DIHEN), microconcentric nebuliser coupled to cyclonic or double pass spray chamber (MCN-C or MCN-DP, respectively) was investigated and compared when used for sample introduction to ICP-MS or ICP-OES. With ICP-OES, in axial viewing mode, intensity distributions across the radius of the plasma (radial intensity profiles) were determined for different spectral lines with Esum 1.85-15.41 eV to determine fundamental plasma properties for various matrices using Vulkan DIN and MCN-C. The results showed that with the MCN-C the ionisation temperature (Tion) was about the same across the measured region of the plasma (±3.0 mm) whereas with the Vulkan DIN the Tion was significantly lower in the centre of the plasma. A large deviation from local thermodynamic equilibrium, as well as deteriorated stability, was observed for the plasma when using the Vulkan DIN.</p><p>With ICP-MS noise power spectra (NPS) were generated to identify sources of noise. NPS showed that the magnitude of white noise for the tested sample introduction systems decreased in the following order: Vulkan DIN > DIHEN > MCN-C > MCN-DP. This order follows the decrease of mean droplet size and span of the size distribution, indicating that the white noise is caused by spatial and temporal non-uniform desolvation and ionisation. Another source of noise arose from the peristaltic pump and the magnitude of pump interference noise decreased in the following order: DIHEN > MCN-C/DP > Vulkan DIN. Mains power interference noise and 1/f noise were lower for the direct injection nebulisers compared to the spray chamber systems. The contribution or effects of these noise components on relative standard deviations of steady-state ion-count rate and isotope ratio measurements is discussed in this thesis.</p><p>Aerosols generated by the Vulkan DIN and the DIHEN were also directly characterised using Particle Dynamic Analysis. The Vulkan DIN produced particles with a mean diameter of ~30 µm and a size distribution between 2-80 µm. With the DIHEN the corresponding values were ~11 µm and 1-40 µm, respectively, with a few particles at 55-78 µm. The mean velocity of particles from the Vulkan DIN was ~10 m s-1 and from the DIHEN ~18 m s-1. The lower velocity allows longer residence time counteracting the effects of the larger droplet size.</p>
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Fundamental Studies on Direct Injection Nebulisers for Sample Introduction in ICP Spectrometry : Aerosol Properties, ICP Characteristics and Analytical PerformanceGoitom Asfaha, Daniel January 2006 (has links)
The performance of different types of nebulisers: Vulkan direct injection nebuliser (Vulkan DIN), direct injection high efficiency nebuliser (DIHEN), microconcentric nebuliser coupled to cyclonic or double pass spray chamber (MCN-C or MCN-DP, respectively) was investigated and compared when used for sample introduction to ICP-MS or ICP-OES. With ICP-OES, in axial viewing mode, intensity distributions across the radius of the plasma (radial intensity profiles) were determined for different spectral lines with Esum 1.85-15.41 eV to determine fundamental plasma properties for various matrices using Vulkan DIN and MCN-C. The results showed that with the MCN-C the ionisation temperature (Tion) was about the same across the measured region of the plasma (±3.0 mm) whereas with the Vulkan DIN the Tion was significantly lower in the centre of the plasma. A large deviation from local thermodynamic equilibrium, as well as deteriorated stability, was observed for the plasma when using the Vulkan DIN. With ICP-MS noise power spectra (NPS) were generated to identify sources of noise. NPS showed that the magnitude of white noise for the tested sample introduction systems decreased in the following order: Vulkan DIN > DIHEN > MCN-C > MCN-DP. This order follows the decrease of mean droplet size and span of the size distribution, indicating that the white noise is caused by spatial and temporal non-uniform desolvation and ionisation. Another source of noise arose from the peristaltic pump and the magnitude of pump interference noise decreased in the following order: DIHEN > MCN-C/DP > Vulkan DIN. Mains power interference noise and 1/f noise were lower for the direct injection nebulisers compared to the spray chamber systems. The contribution or effects of these noise components on relative standard deviations of steady-state ion-count rate and isotope ratio measurements is discussed in this thesis. Aerosols generated by the Vulkan DIN and the DIHEN were also directly characterised using Particle Dynamic Analysis. The Vulkan DIN produced particles with a mean diameter of ~30 µm and a size distribution between 2-80 µm. With the DIHEN the corresponding values were ~11 µm and 1-40 µm, respectively, with a few particles at 55-78 µm. The mean velocity of particles from the Vulkan DIN was ~10 m s-1 and from the DIHEN ~18 m s-1. The lower velocity allows longer residence time counteracting the effects of the larger droplet size.
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Intercalation von Stickstoff und Wasserstoff in Sr2N sowie ortsabhängige Feststoffcharakterisierung mit LaserablationChemnitzer, René 02 August 2006 (has links) (PDF)
Die Strukturen der Erdalkalimetall-Subnitride (EA2N) von Calcium, Strontium und Barium ermöglichen mit ihrem schichtartigen Aufbau aus EA6N-Oktaedern Intercalationsreaktionen. Die Redox-Intercalation von Stickstoff in Sr2N wurde an Einkristallen untersucht. Nur durch eine drastische Erhöhung des Reaktionsgasdruckes im Vergleich zu den Reaktionen an mikrokristallinen Proben wurde die Intercalation der Diazenidionen in die Kristalle zu Sr4N3 und SrN möglich. Für eine analoge Intercalation von Wasserstoff in Sr2N konnten die Reaktionsbedingungen dahingehend optimiert werden, dass erstmals phasenreines Strontiumnitridhydrid (Sr2N)H bzw. deuterid (Sr2N)D erhalten wurde. Anhand von Intercalationsreaktionen mit Sr2N Kristallen konnte gezeigt werden, dass der Intercalationsprozess, erkennbar an der deutlichen Farbänderung von schwarz nach bersteinfarben, von außen nach innen fortschreitet. Als Methode zur räumlich aufgelösten Analyse wurde die Laserablation, in Kombination mit einem ICP - Massenspektrometer (LA-ICP-MS) verwendet. In der Literatur beschriebene Quantifizierungsstrategien wurden auf die Anwendbarkeit für die gegebene Fragestellung untersucht. Mit der ortsaufgelösten Analyse von Einkristallen konnte gezeigt werden, dass die Intercalation von Stickstoff in die Kristalle kontinuierlich von den Kanten zur Kristallmitte fortschreitet.
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Determinação de espécies de antimônio em antimoniato de megluminaMoreira, Clarissa Marques 04 August 2008 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / In this study different methods for speciation of Sb(III) and Sb(V) in meglumine
antimoniate (NMG) were evaluated. Liquid chromatography (LC) combined or not
with hydride generation (HG) was investigated for separation of Sb(III) and Sb(V).
Inductively coupled plasma mass spectrometry (ICP-MS) was used as detector. A
flow injection system together with hydride generation (FI-HG) coupled with atomic
absorption spectrometry (AAS) was also employed for the selective determination of
Sb(III) in presence of Sb(V). Two anion-exchange columns (Dionex, IonPacAS14 and
Hamilton, PRP-X100) were evaluated for Sb(III) and Sb(V) separation by LC.
Parameters related to the mobile phase, such as type (EDTA, potassium phthalate,
and potassium phthalate + EDTA), concentration (0.5 to 10 mmol L-1), pH (3.5 to
7.0), flow rate (0.25 to 1.75 mL min-1) and elution mode (isocratic and gradient) were
studied. The volume of sample injected into the chromatograph was set at 200 μL.
For the chromatographic separation, the mobile phase which led to improved
separations of Sb(III) and Sb(V) was the EDTA in concentrations of 0.5 mmol L-1 and
1.0 mmol L-1 for the IonPac and PRP-X100 columns, respectively. The most
appropriate parameters related to the FI-HG system were also evaluated and set,
such as reductant of Sb(III) (NaBH4 0.1%, m/v), complexant of Sb(V) (10% m/v citric
acid,), water as the sample carrier, analytical path (300 cm), volume of sample (100
μL), total flow rate of solutions (8.5 mL min-1) and flow rate of carrier gas (0.4 mL
min-1). In order to identify and/or quantify the species of Sb present in the NMG, the
samples were diluted in water only. Through the use of LC-ICP-MS it was only
possible to quantify the Sb(V), whereas the presence of Sb(III) was not detected. The
determination of Sb(III) was only possible through FI-HG AAS, FI-HG-ICP-MS and
LC-HG-ICP-MS (by combination of conditions set for LC and FI-HG individually).
Similar results for Sb(III) were obtained through the techniques FI-HG AAS and HGICP-
MS. Thus, it was possible to quantify free Sb(III) and Sb(V), while probable
compounds of Sb(III) and/or Sb(V) bound to NMG were observed but could not be
identified and quantified, mainly because of lack of reference solutions and difficulty
in separating the observed Sb species. The precision of methods for determination of
Sb(III) and Sb(V) (expressed as relative standard deviation for 5 consecutive
measurements) was about 9% and 3% respectively. As there were no certified
reference materials to evaluate the accuracy of the developed methods, recovery
tests of Sb(III) and Sb(V) were made, where they were in the range 96 to 101% for
Sb(V) and 85 to 104% for Sb(III). Moreover, the results were compared with those
obtained by official methods to quantify Sb(III), Sb(V) and Sb total in meglumine
antimoniate. / Neste trabalho foram avaliados diferentes métodos para a análise de
especiação de Sb(III) e Sb(V) em antimoniato de meglumina (NMG). Cromatografia a
líquido (LC) combinada, ou não, com a técnica de geração de hidretos (HG) foi
investigada para a separação de espécies de Sb. A espectrometria de massa com
plasma indutivamente acoplado (ICP-MS) foi empregada como detector. Um sistema
de injeção em fluxo (FI) em conjunto com HG (FI-HG) e acoplado à espectrometria
de absorção atômica (AAS) foi também empregado para a determinação seletiva de
Sb(III) na presença de Sb(V). Duas colunas de troca aniônica (Dionex, IonPacAS14
e Hamilton, PRP-X100) foram avaliadas para separar as espécies de Sb por LC.
Parâmetros relacionados com a fase móvel, tais como tipo (EDTA, ftalato de
potássio e EDTA + ftalato de potássio), concentração (0,5 a 10 mmol L-1), pH (3,5 a
7,0), vazão (0,25 a 1,75 mL min-1) e o modo de eluição (isocrático e gradiente) foram
estudados. O volume de amostra injetada no cromatógrafo foi fixado em 200 μL.
Para a separação cromatográfica, a fase móvel que levou a melhores separações de
Sb(III) e Sb(V) foi o EDTA nas concentrações de 0,5 mmol L-1 e 1,0 mmol L-1, para
as colunas IonPac e PRP-X100, respectivamente. Os parâmetros relacionados com
o sistema FI-HG mais adequados foram também avaliados e escolhidos, tais como o
redutor do Sb(III) (NaBH4 0,1%, m/v), complexante do Sb(V) (ácido cítrico 10%, m/v),
a água como carregador da amostra, o percurso analítico (300 cm), volume de
amostra (100 μL), a vazão total das soluções (8,5 mL min-1) e a vazão do gás de
arraste (0,4 mL min-1). Para a identificação e/ou quantificação das espécies de Sb
presentes no NMG, as amostras foram somente diluídas em água. Com o emprego
de LC-ICP-MS foi possível quantificar somente o Sb(V), não sendo detectada a
presença da espécie Sb(III). A determinação de Sb(III) foi somente possível
mediante as técnicas FI-HG AAS, FI-HG-ICP-MS e LC-HG-ICP-MS (esta mediante
combinação das condições ajustadas para LC e FI-HG individualmente). Resultados
concordantes para Sb(III) foram obtidos mediante as técnicas FI-HG AAS e FI-HGICP-
MS. Desta forma, foi possível quantificar Sb(III) e Sb(V) livres, enquanto que
possíveis compostos de Sb(III) e/ou Sb(V) ligados ao NMG foram observados mas
não puderam ser identificados e quantificados, principalmente por causa da falta de
soluções de referência e dificuldade de separação das possíveis espécies de Sb
observadas. A precisão dos métodos de determinação de Sb(III) e Sb(V) (expressa
como desvio padrão relativo para 5 medições consecutivas) foi cerca de 9% e 3%,
respectivamente. Como não havia materiais de referência certificados para avaliar a
exatidão dos métodos desenvolvidos, foram feitos testes de recuperação de Sb(III) e
Sb(V), sendo que as mesmas ficaram na faixa de 96 a 101% para o Sb(V) e de 85 a
104% para o Sb(III). Além disso, os resultados obtidos foram comparados com
aqueles obtidos por métodos oficiais para a quantificação Sb(III), Sb(V) e Sb total no
antimoniato de meglumina.
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