This study deals with B, S, and P determination in mineral fertilizer and S in commercial sulfur-formulation using inductively coupled plasma optical emission spectrometry. According to multivariate optimization using a Doehlert matrix, the analytes extraction in fertlizer can be conducted in open flask and heating on hot plate or in closed flask in microwave oven. However, when S is present in its elemental form in the fertilizer, the sample must be decomposed in closed flask in microwave oven for accurate S quantification. The uncertainties of the method were estimated according to the bottom-up approach, which were 7.1, 4.3, and 7.8% for B, S and P, respectively. The main sources of uncertainty identified were the intermediate precision, accuracy, regression of the calibration curve and errors originated from volumetric flasks and pipettes. Satisfactory results were obtained in the analysis of certified reference materials and sample from inter-laboratory programs as well as S recovery in a commercial elemental sulfur sample.

O presente estudo trata da aplicação da extração no ponto nuvem (CPE) e geração de hidretos (HG) para a determinação de Sb e Se por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). O complexante utilizado foi o dietilditiofosfato de amônio (DDTP), enquanto que Triton X-114 foi usado como surfactante para a formação das micelas. As condições para a pré-concentração de Sb(III) e Se(IV), redução de Se(VI) e Sb(V), geração dos respectivos hidretos e interferências foram avaliadas e discutidas. O desempenho da HG foi comparado com o da nebulização pneumática (PN) para introduzir a fase rica em surfactante no plasma. Mediante aplicação da HG, os limites de detecção obtidos para Se(IV) e Sb(III) foram 0,05 e 0,08 µg L-1, respectivamente. No caso da aplicação da PN, os limites de detecção do Se(IV) e Sb(III) foram 0,90 e 2,90 µg L-1, respectivamente. Foram analisadas amostras de nozes e castanha do Pará, água e vinho branco. O Se(IV) foi quantificado na castanha do Pará, enquanto que o Sb(III) foi quantificado em água de estuário, água de mar e água mineral embalada em garrafa feita de politereftalato de etileno (PET).

This study deals with the application of cloud point extraction (CPE) and hydride generation (HG) for determination of Sb and Se using inductively coupled plasma optical emission spectrometry (ICP OES). The complexing agent was ammonium diethylditiophosphate (DDTP), whereas Triton X-114 was used as surfactant for the formation of micelles. Conditions for Sb(III) and Se(IV) preconcentration, reduction of Se(VI) and Sb(V), hydrides generation and interferences were discussed. The performance of HG was compared with pneumatic nebulization (PN) for introducing the surfactant-rich phase into the plasma. Upon application of HG, the limits of detection (LODs) for Se(IV) and Sb(III) were 0.05 and 0.08 µg L-1, respectively. Limits of detection using PN were 0.90 and 2.90 ug L-1 for Se(IV) and Sb(III), respectively. Samples of nuts, water and white wine were analyzed. Selenium(IV) was quantified in Brazil nut whereas Sb(III) was in estuarine water, seawater and mineral water stored in polyethylene terephthalate (PET) bottle.

Elementos majoritários, minoritários e traço em vinhos provenientes de países produtores na América do Sul (Argentina, Brasil, Chile e Uruguai) foram determinados. A espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) e a espectrometria de massa com plasma indutivamente acoplado (ICP-MS) em conjunto com nebulização pneumática e/ou nebulização ultra-sônica foram utilizadas. Foram determinados 45 elementos (Al, Ag, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Gd, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nd, Ni, P, Pb, Pr, Rb, Sb, Sn, Se, Sm, Sr, Tb, Ti, Tl, Tm, U, V, Yb e Zn) em 53 vinhos tintos. Mediante análise multivariada, os vinhos puderam ser discriminados de acordo com o país de origem, independentemente do tipo da uva. Os elementos discriminantes foram Tl, U, Li, Rb e Mg.

Major, minor and trace elements in wines from wine-producing countries in South America (Argentina, Brazil, Chile, and Uruguay) were determined. Inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry (ICP-MS) combined with pneumatic and/or ultrasonic nebulization were used. The concentrations of 45 elements (Al, Ag, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Gd, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nd, Ni, P, Pb, Pr, Rb, Sb, Sn, Se, Sm, Sr, Tb, Ti, Tl, Tm, U, V, Yb, and Zn) in 53 red wines were determined. By means of multivariate analysis, the wines could be discriminated according to the country of origin, regardless of the type of grape. The discriminant elements were Tl, U, Li, Rb, and Mg.

Baixas concentrações dos catorze elementos de ocorrência natural da série lantanídeos foram diretamente determinadas por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Avaliaram-se interferências espectrais e linhas espectrais mais adequadas foram selecionadas. Os desempenhos da nebulização pneumática e ultra-sônica foram comparados com respeito aos limites de detecção, para ambas as posições de observação do plasma, radial e axial. A influência da potência de radiofrequência sobre a precisão e exatidão foi também investigada para os dois tipos de nebulizadores. O método foi aplicado à determinação dos lantanídeos em amostras ambientais (sedimentos, cinza de carvão e água fluvial). Este trabalho demonstrou que é possível a determinação direta de baixas concentrações (i.e. ng g-1 e ng L-1) dos lantanídeos de ocorrência natural por ICP OES.

Low concentrations of the fourteen naturally occurring lanthanides were directly determined by inductively coupled plasma optical emission spectrometry (ICP OES). Spectral interferences were evaluated and the most appropriate spectral lines selected. Pneumatic and ultrasonic nebulization performances were compared with respect to limits of detection for both radial and axial viewed plasma. The influence of plasma applied power on precision and accuracy was studied for both nebulizers. The developed method was applied to lanthanides determination in environmental samples (sediments, coal fly ash and river water). This work demonstrates that the use of ultrasonic nebulization combined with axially viewed plasma allowed direct determination of low concentrations (at ng g-1 and ng L-1 levels) of all naturally occurring lanthanides by ICP OES.

Foi desenvolvido um sistema em linha para a especiação de Hg orgânico (Hg org) e Hg inorgânico (Hg inorg) em chorume. Clorocomplexos produzidos a partir do Hg inorg são separados em uma coluna trocadora de ânions. O Hg retido na coluna é eluído com NaBH4 na presença de HCl. O Hg0 produzido é medido por espectrometria de absorção atômica com geração de vapor frio (CV AAS). O Hg org, que não fica retido na coluna, é misturado com NaBH4 produzindo espécies voláteis de Hg, as quais são amalgamadas numa rede de Au/Pt. O Hg é removido desta coluna por aquecimento a 600 °C e medido por CV AAS. Para a especiação de Hg inorg e Hg org em chorume, as amostras são centrifugadas, filtradas e tratadas com HCl. Os limites de detecção (3 s) são 9 e 12 ng L-1 de Hg para Hg inorg e Hg org, respectivamente. A freqüência de análise é 22 h-1.

This work deals with on line speciation of organic Hg (Hg org) and inorganic Hg (Hg inorg) in urban landfill leachate. Chlorocomplexes of Hg inorg are produced in HCl medium and retained on an anion exchange column. The retained Hg is eluted with NaBH4 in presence of HCl. Hg0 is produced and then measured by cold vapor atomic absorption spectrometry (CV AAS). Hg org does not interact with the resin and is mixed with NaBH4 at the exit of the column producing volatile species of Hg that are then amalgamated by a gauze of Au/Pt. Mercury is removed from the gauze by heating to 600 °C and subsequently measured by CV AAS. For Hg inorg and Hg org speciation in urban landfill leachate, the samples are centrifuged, filtered and treated with HCl. The detection limits (3 s) of Hg inorg and Hg org are 9 and 12 ng L-1 of Hg, respectively. The analysis frequency is 22 h-1.

This work deals with paint decomposition methods for major, minor and trace elements determination. Three methods were investigated: (1) decomposition in closed quartz vessel and heating in microwave oven; (2) decomposition in open vessel using HNO3 and ashing, following the ASTM D 3335-85a method; and (3) decomposition in open vessel using HNO3 + HF and ashing. Paints of different types and colours were analyzed, in which several elements were determined using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP OES). It was observed that method (1) is appropriate for trace, minor and major elements determination, while method (3) is appropriate for Ti.

É proposto um método para a determinação de fluoreto em carvão mineral. O mesmo é baseado no emprego da pirohidrólise para a separação do fluoreto da amostra e posterior determinação do analito por potenciometria direta, com eletrodo íon seletivo. O sistema utilizado para a realização da pirohidrólise foi desenvolvido e a influência do V2O5 como catalisador na reação de pirohidrólise foi investigada, sendo verificado que o mesmo não influencia sobre a liberação do fluoreto presente na amostra. Amostras certificadas e não certificadas de carvão mineral foram analisadas. Resultados precisos (desvio padrão relativo inferior a 7%) e exatos (recuperação do fluoreto de acordo com os valores certificados) foram obtidos. O limite de quantificação (LOQ) do método foi de 5,0 mgF/g de amostra, usando 20 mg de amostra e volume final de 10 mL. A freqüência de análise foi de 5 amostras h-1.

A method for the determination of fluoride in coal using pyrohydrolysis for sample decomposition is proposed. An apparatus was constructed, and the influence of vanadium pentoxide (V2O5) as a catalyst for the pyrohydrolysis reaction was investigated. It was verified that V2O5 does not influence the release of fluoride from coal. Certified and non-certified samples were analysed using an ion selective electrode (ISE) for analyte detection. Precise (RSD < 7%) and accurate (recovery in accordance with certified values) results were obtained. The limit of quantification (LOQ) of the method was 5.0 mgF/g of sample, using 20 mg of sample and a final dilution to 10 mL. The sample frequency was 5 samples h-1.

Aspects related to the quality of human hair analysis are presented, such as sample collection, sample preparation, determination of trace elements and application examples. Also the hair morphology, the importance of this analysis and its uses and meanings are discussed.