The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

Anderson Schwingel Ribeiro - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of the use of a reflux system for sample preparation of processed fruit juices and subsequent determination of Cr, Cu, K, Mg, Na, Pb and Zn by Atomic Spectrometry Techniques.
    Food chemistry, 2017
    Co-Authors: Camila Corrêa Pereira, Alexander Ossanes De Souza, Eliézer Quadro Oreste, Mariana Antunes Vieira, Anderson Schwingel Ribeiro
    Abstract:

    The acid decomposition method was applied for the sample preparation of processed fruit juice. The decomposition of 15mL of juice sample using HNO3 and H2O2 was performed in a digester block with reflux system and heated at 200°C for 150min. The limits of detection were 0.03; 0.24; 0.8; 0.008; 0.026 and 0.056mgL-1 for Cr, Cu, K, Mg, Na and Zn, respectively and for Pb was 0.99μgL-1. The accuracy was evaluated by spiked experiments (80 to 119%). Four processed fruit juice samples commercialized in Brazil (strawberry, mango, peach, and orange) were analyzed and indicated the absence of Cr, Zn and Cu in the samples, except for Cu in strawberry juice. Pb was found in the mango juice sample (17.8±0.9μgL-1) and the concentration is below the maximum values recommended by Brazilian legislation for juices of citric fruits (0.3mgkg-1).

  • Evaluation of the Use of a Reflux System for Sample Preparation of Xanthan Gum and Subsequent Determination of Ca, Cu, K, Mg, Na and Zn by Atomic Spectrometry Techniques
    Journal of the Brazilian Chemical Society, 2015
    Co-Authors: Michele B. Da Rosa, Eliézer Quadro Oreste, Anderson Schwingel Ribeiro, Daisa Hakbart Bonemann, Amanda Ávila Rodrigues, Claire Tondo Vendruscolo, Angelita Da Silveira Moreira, Adriane Medeiros Nunes
    Abstract:

    The aim of this study was to evaluate the performance of a reflux system adapted in the digestion tubes in sample preparation of xanthan gum for subsequent determination of Ca, Cu, K, Mg, Na and Zn by using spectrometric Techniques. Through the proposed method, the samples were digested with HNO3 for 3 h in a digester block at 220 °C. The accuracy of the method was evaluated by comparing the results with another sample preparation method and by using recovery tests, which results vary between 83 and 103%. The efficiency of digestion was assessed and significant results were verified through residual carbon values, which were five times lower compared to conventional acid digestion in open system, with use of HNO3 and HClO4. The proposed methodology is a simple and accurate analytical strategy, which does not require the use of special equipment, neither a mixture of strong oxidizing acid in the sample preparation.

Katarzyna Wrobel - One of the best experts on this subject based on the ideXlab platform.

  • determination of total arsenic and speciation analysis in mexican maize tortillas by hydride generation microwave plasma Atomic emission Spectrometry and high performance liquid chromatography inductively coupled plasma mass Spectrometry
    Analytical Methods, 2017
    Co-Authors: Moises Guerrero Esperanza, Eunice Yanez Barrientos, Kazimierz Wrobel, Francisco Javier Acevedo Aguilar, Alma Rosa Corrales Escobosa, Katarzyna Wrobel
    Abstract:

    The determination of total arsenic (tAs), inorganic As (iAs = As(III) + As(V)) and As speciation in Mexican maize tortillas has been undertaken for the first time. Hydride generation – microwave plasma Atomic emission Spectrometry (HG-MP-AES) with tellurium (sodium tellurite Te(IV)) as the internal standard (IS) yielded tAs results in good agreement with those provided by inductively coupled plasma mass Spectrometry (ICP-MS). In seven products from local markets, tAs was found in the range of 21.8–192 μg As kg−1. Analysis of As(III), As(V), MMAs(V), and DMAs(V) by an established anion exchange liquid chromatography – ICP-MS procedure showed that iAs corresponded to 72.3–98.0% of tAs. A non-chromatographic procedure was envisioned for iAs: diluted tortilla extract or calibration solution (pH 9.0) was loaded on a strong anion exchange cartridge modified with silver chloride, iAs fraction was collected and analyzed by HG-MP-AES with IS. For tAs by HG-MP-AES (with IS) the method quantification limit was 47.6 μg As kg−1 whereas for iAs it got worse (95 μg As kg−1) due to the low recovery of this As form in SPE ( 93% while analyzing natural water with off-line quantification by any of the two Atomic Spectrometry Techniques, indicating that the chemical matrix of tortillas was responsible for poor SPE performance. It is concluded that HG-MP-AES with IS is a cost-effective alternative for the determination of tAs that offers improved precision under a non-rigorous protocol; however, efficient separation/preconcentration of iAs by SPE is still a challenge.

  • Determination of total arsenic and speciation analysis in Mexican maize tortillas by hydride generation – microwave plasma Atomic emission Spectrometry and high performance liquid chromatography – inductively coupled plasma – mass Spectrometry
    Analytical Methods, 2017
    Co-Authors: Moises Guerrero Esperanza, Eunice Yanez Barrientos, Kazimierz Wrobel, Francisco Javier Acevedo Aguilar, Alma Rosa Corrales Escobosa, Katarzyna Wrobel
    Abstract:

    The determination of total arsenic (tAs), inorganic As (iAs = As(III) + As(V)) and As speciation in Mexican maize tortillas has been undertaken for the first time. Hydride generation – microwave plasma Atomic emission Spectrometry (HG-MP-AES) with tellurium (sodium tellurite Te(IV)) as the internal standard (IS) yielded tAs results in good agreement with those provided by inductively coupled plasma mass Spectrometry (ICP-MS). In seven products from local markets, tAs was found in the range of 21.8–192 μg As kg−1. Analysis of As(III), As(V), MMAs(V), and DMAs(V) by an established anion exchange liquid chromatography – ICP-MS procedure showed that iAs corresponded to 72.3–98.0% of tAs. A non-chromatographic procedure was envisioned for iAs: diluted tortilla extract or calibration solution (pH 9.0) was loaded on a strong anion exchange cartridge modified with silver chloride, iAs fraction was collected and analyzed by HG-MP-AES with IS. For tAs by HG-MP-AES (with IS) the method quantification limit was 47.6 μg As kg−1 whereas for iAs it got worse (95 μg As kg−1) due to the low recovery of this As form in SPE ( 93% while analyzing natural water with off-line quantification by any of the two Atomic Spectrometry Techniques, indicating that the chemical matrix of tortillas was responsible for poor SPE performance. It is concluded that HG-MP-AES with IS is a cost-effective alternative for the determination of tAs that offers improved precision under a non-rigorous protocol; however, efficient separation/preconcentration of iAs by SPE is still a challenge.

Maria Tereza Weitzel Dias Carneiro - One of the best experts on this subject based on the ideXlab platform.

  • Extraction induced by emulsion breaking for determination of Ba, Ca, Mg and Na in crude oil by inductively coupled plasma optical emission Spectrometry
    Microchemical Journal, 2016
    Co-Authors: Alex M. Trevelin, Rúbia E.s. Marotto, Eustáquio V.r. Castro, Geisamanda Pedrini Brandão, Ricardo J. Cassella, Maria Tereza Weitzel Dias Carneiro
    Abstract:

    The selection of the sample preparation method is one of the most critical steps in the determination of metals using Atomic Spectrometry Techniques. The aim of this paper was to propose the use of a novel strategy for crude oil sample preparation, based on the extraction induced by emulsion breaking, prior to the determination of Ba, Ca, Mg and Na by inductively coupled plasma optical emission Spectrometry (ICP OES). The emulsions were prepared by mixing the crude oils samples diluted in xylene with 5% m/v Triton X-100 solution in 10% v/v HNO3. The emulsion breaking was performed by heating at 80 ± 2 °C following by centrifugation to improve the separation, resulting in two distinct phases. The aqueous phase was analysed by ICP OES using inorganic standards solutions for external calibration. Ba, Ca, Mg and Na were totally extracted at a single extraction step. The limits of detection were 0.12, 1.2, 0.14 and 5.8 μg L− 1 for Ba, Ca, Mg and Na, respectively. The percentage recoveries ranged from 99 to 104% and the good agreement with the values of the certified reference material (NIST 1634c), when student-t test was applied at 95% confidence limit (p < 0.05), warranted the accuracy of the procedure.

Wojciech Piekoszewski - One of the best experts on this subject based on the ideXlab platform.

  • the analytical calibration in bio imaging mapping of the metallic elements in biological samples definitions nomenclature and strategies state of the art
    Talanta, 2015
    Co-Authors: Kamil Jurowski, Boguslaw Buszewski, Wojciech Piekoszewski
    Abstract:

    Nowadays, studies related to the distribution of metallic elements in biological samples are one of the most important issues. There are many articles dedicated to specific analytical Atomic Spectrometry Techniques used for mapping/(bio)imaging the metallic elements in various kinds of biological samples. However, in such literature, there is a lack of articles dedicated to reviewing calibration strategies, and their problems, nomenclature, definitions, ways and methods used to obtain quantitative distribution maps. The aim of this article was to characterize the analytical calibration in the (bio)imaging/mapping of the metallic elements in biological samples including (1) nomenclature; (2) definitions, and (3) selected and sophisticated, examples of calibration strategies with analytical calibration procedures applied in the different analytical methods currently used to study an element׳s distribution in biological samples/materials such as LA ICP-MS, SIMS, EDS, XRF and others. The main emphasis was placed on the procedures and methodology of the analytical calibration strategy. Additionally, the aim of this work is to systematize the nomenclature for the calibration terms: analytical calibration, analytical calibration method, analytical calibration procedure and analytical calibration strategy. The authors also want to popularize the division of calibration methods that are different than those hitherto used. This article is the first work in literature that refers to and emphasizes many different and complex aspects of analytical calibration problems in studies related to (bio)imaging/mapping metallic elements in different kinds of biological samples.

  • The analytical calibration in (bio)imaging/mapping of the metallic elements in biological samples--definitions, nomenclature and strategies: state of the art.
    Talanta, 2014
    Co-Authors: Kamil Jurowski, Boguslaw Buszewski, Wojciech Piekoszewski
    Abstract:

    Nowadays, studies related to the distribution of metallic elements in biological samples are one of the most important issues. There are many articles dedicated to specific analytical Atomic Spectrometry Techniques used for mapping/(bio)imaging the metallic elements in various kinds of biological samples. However, in such literature, there is a lack of articles dedicated to reviewing calibration strategies, and their problems, nomenclature, definitions, ways and methods used to obtain quantitative distribution maps. The aim of this article was to characterize the analytical calibration in the (bio)imaging/mapping of the metallic elements in biological samples including (1) nomenclature; (2) definitions, and (3) selected and sophisticated, examples of calibration strategies with analytical calibration procedures applied in the different analytical methods currently used to study an element׳s distribution in biological samples/materials such as LA ICP-MS, SIMS, EDS, XRF and others. The main emphasis was placed on the procedures and methodology of the analytical calibration strategy. Additionally, the aim of this work is to systematize the nomenclature for the calibration terms: analytical calibration, analytical calibration method, analytical calibration procedure and analytical calibration strategy. The authors also want to popularize the division of calibration methods that are different than those hitherto used. This article is the first work in literature that refers to and emphasizes many different and complex aspects of analytical calibration problems in studies related to (bio)imaging/mapping metallic elements in different kinds of biological samples.

Krystyna Pyrzynska - One of the best experts on this subject based on the ideXlab platform.

  • Recent developments in the determination of gold by Atomic Spectrometry Techniques
    Spectrochimica Acta Part B: Atomic Spectroscopy, 2005
    Co-Authors: Krystyna Pyrzynska
    Abstract:

    Abstract Determination of gold in different kinds of samples is often a challenging task for analysts. Its concentration is usually very low and the sample matrix may cause serious interferences during measurement. Therefore, preconcentration and separation methods should be used to solve these problems and render more sensitive, accurate and interference-free determination. The recent developments in sample treatment, such as liquid and solid phase extraction, coprecipitation and electrodeposition, are presented. In addition, important extension and improvements in Atomic Spectrometry Techniques — mainly electrothermal Atomic absorption Spectrometry and inductively coupled plasma mass Spectrometry, are discussed.