Mariela Matos | Pontificia Universidad Catolica del Peru (original) (raw)
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Papers by Mariela Matos
Spectrochimica Acta Part B: Atomic Spectroscopy, 2007
Food Chemistry, 2010
... In another study, the daily dietary intake of arsenic found for the Spanish population from .... more ... In another study, the daily dietary intake of arsenic found for the Spanish population from ... The certified reference materials NIST 1573 (Tomato leaves) and NIST 1568a (Rice Flour) were obtained ... it is possible to conclude that no analyte loss and no contamination were occurred ...
Food Analytical Methods, 2010
Page 1. Screening of Toxic Inorganic Arsenic Species in Garlic (Allium sativum L.) Hadla Sousa-Fe... more Page 1. Screening of Toxic Inorganic Arsenic Species in Garlic (Allium sativum L.) Hadla Sousa-Ferreira & Mariela N. Matos-Reyes & M. Luisa Cervera & Sergio L. Costa-Ferreira & Miguel de la Guardia Received: 29 July 2010 ...
Spectrochimica Acta Part B-atomic Spectroscopy, 2007
A fast, sensitive and simple non-chromatographic analytical method was developed for the speciati... more A fast, sensitive and simple non-chromatographic analytical method was developed for the speciation analysis of toxic arsenic species in cereal samples, namely rice and wheat semolina. An ultrasound-assisted extraction of the toxic arsenic species was performed with 1 mol L - 1 H 3PO 4 and 0.1% (m/v) Triton XT-114. After extraction, As(III), As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) concentrations were determined by hydride generation atomic fluorescence spectrometry using a series of proportional equations corresponding to four different experimental reduction conditions. The detection limits of the method were 1.3, 0.9, 1.5 and 0.6 ng g - 1 for As(III), As(V), DMA and MMA, respectively, expressed in terms of sample dry weight. Recoveries were always greater than 90%, and no species interconversion occurred. The speciation analysis of a rice flour reference material certified for total arsenic led to coherent results, which were also in agreement with other speciation studies made on the same certified reference material.
Food Chemistry, 2010
... In another study, the daily dietary intake of arsenic found for the Spanish population from .... more ... In another study, the daily dietary intake of arsenic found for the Spanish population from ... The certified reference materials NIST 1573 (Tomato leaves) and NIST 1568a (Rice Flour) were obtained ... it is possible to conclude that no analyte loss and no contamination were occurred ...
Food Analytical Methods
It has been evidenced that arsenic in garlic is present in the most toxic inorganic species As(II... more It has been evidenced that arsenic in garlic is present in the most toxic inorganic species As(III) and As(V). A non-chromatographic speciation method has been developed for the screening of inorganic toxic species of As in garlic samples by hydride generation atomic fluorescence spectrometry. The determination of As(III) and As(V) was based on the different efficiencies of hydride generation with NaBH4 with and without a previous reduction with ascorbic acid and KI using a system of two proportional equations corresponding to these two different measurement conditions. The extraction efficiency of total arsenic and the stability of As(III) and As(V) in different extraction media (sulphuric acid, perchloric acid, and methanol/water) were evaluated. Based on the extraction yield and the stability of extracted species, 1.0 mol L−1 H2SO4 was selected as the best extracting solution for speciation analysis. The methodology developed allows us a limit of detection of 0.8 and 0.6 ng g−1 for As(III) and As(V), respectively. The relative standard deviation values were 4% for As(III) and 7% for As(V). This method was applied to determine As(III), As(V), and total As in different Spanish garlic samples. The arsenic (III) content varied from 17.1 to 22.1 ng g−1 and As(V) from 54.7 to 67.6 ng g−1. The accuracy of the method was confirmed by the analysis of a certified reference material of tomato leaves treated in the same way as the garlic samples.
Spectrochimica Acta Part B-atomic Spectroscopy, 2007
Spectrochimica Acta Part B-atomic Spectroscopy, 2005
Spectrochimica Acta Part B: Atomic Spectroscopy, 2007
Food Chemistry, 2010
... In another study, the daily dietary intake of arsenic found for the Spanish population from .... more ... In another study, the daily dietary intake of arsenic found for the Spanish population from ... The certified reference materials NIST 1573 (Tomato leaves) and NIST 1568a (Rice Flour) were obtained ... it is possible to conclude that no analyte loss and no contamination were occurred ...
Food Analytical Methods, 2010
Page 1. Screening of Toxic Inorganic Arsenic Species in Garlic (Allium sativum L.) Hadla Sousa-Fe... more Page 1. Screening of Toxic Inorganic Arsenic Species in Garlic (Allium sativum L.) Hadla Sousa-Ferreira & Mariela N. Matos-Reyes & M. Luisa Cervera & Sergio L. Costa-Ferreira & Miguel de la Guardia Received: 29 July 2010 ...
Spectrochimica Acta Part B-atomic Spectroscopy, 2007
A fast, sensitive and simple non-chromatographic analytical method was developed for the speciati... more A fast, sensitive and simple non-chromatographic analytical method was developed for the speciation analysis of toxic arsenic species in cereal samples, namely rice and wheat semolina. An ultrasound-assisted extraction of the toxic arsenic species was performed with 1 mol L - 1 H 3PO 4 and 0.1% (m/v) Triton XT-114. After extraction, As(III), As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) concentrations were determined by hydride generation atomic fluorescence spectrometry using a series of proportional equations corresponding to four different experimental reduction conditions. The detection limits of the method were 1.3, 0.9, 1.5 and 0.6 ng g - 1 for As(III), As(V), DMA and MMA, respectively, expressed in terms of sample dry weight. Recoveries were always greater than 90%, and no species interconversion occurred. The speciation analysis of a rice flour reference material certified for total arsenic led to coherent results, which were also in agreement with other speciation studies made on the same certified reference material.
Food Chemistry, 2010
... In another study, the daily dietary intake of arsenic found for the Spanish population from .... more ... In another study, the daily dietary intake of arsenic found for the Spanish population from ... The certified reference materials NIST 1573 (Tomato leaves) and NIST 1568a (Rice Flour) were obtained ... it is possible to conclude that no analyte loss and no contamination were occurred ...
Food Analytical Methods
It has been evidenced that arsenic in garlic is present in the most toxic inorganic species As(II... more It has been evidenced that arsenic in garlic is present in the most toxic inorganic species As(III) and As(V). A non-chromatographic speciation method has been developed for the screening of inorganic toxic species of As in garlic samples by hydride generation atomic fluorescence spectrometry. The determination of As(III) and As(V) was based on the different efficiencies of hydride generation with NaBH4 with and without a previous reduction with ascorbic acid and KI using a system of two proportional equations corresponding to these two different measurement conditions. The extraction efficiency of total arsenic and the stability of As(III) and As(V) in different extraction media (sulphuric acid, perchloric acid, and methanol/water) were evaluated. Based on the extraction yield and the stability of extracted species, 1.0 mol L−1 H2SO4 was selected as the best extracting solution for speciation analysis. The methodology developed allows us a limit of detection of 0.8 and 0.6 ng g−1 for As(III) and As(V), respectively. The relative standard deviation values were 4% for As(III) and 7% for As(V). This method was applied to determine As(III), As(V), and total As in different Spanish garlic samples. The arsenic (III) content varied from 17.1 to 22.1 ng g−1 and As(V) from 54.7 to 67.6 ng g−1. The accuracy of the method was confirmed by the analysis of a certified reference material of tomato leaves treated in the same way as the garlic samples.
Spectrochimica Acta Part B-atomic Spectroscopy, 2007
Spectrochimica Acta Part B-atomic Spectroscopy, 2005