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Soriano ML, Zougagh M, Ríos Á, Valcárcel M. Analytical reliability of simple, rapid, minuturizated, direct analytical processes: A call to arms. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2019.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Valcárcel M, Lucena R. Synergistic relationships between Analytical Chemistry and written standards. Anal Chim Acta 2013; 788:1-7. [PMID: 23845474 DOI: 10.1016/j.aca.2013.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 04/01/2013] [Accepted: 04/03/2013] [Indexed: 12/01/2022]
Abstract
This paper describes the mutual impact of Analytical Chemistry and several international written standards (norms and guides) related to knowledge management (CEN-CWA 14924:2004), social responsibility (ISO 26000:2010), management of occupational health and safety (OHSAS 18001/2), environmental management (ISO 14001:2004), quality management systems (ISO 9001:2008) and requirements of the competence of testing and calibration laboratories (ISO 17025:2004). The intensity of this impact, based on a two-way influence, is quite different depending on the standard considered. In any case, a new and fruitful approach to Analytical Chemistry based on these relationships can be derived.
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Affiliation(s)
- Miguel Valcárcel
- Department of Analytical Chemistry, University of Córdoba, 14071 Córdoba, Spain.
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Aguilera-Herrador E, Cruz-Vera M, Valcárcel M. Analytical connotations of point-of-care testing. Analyst 2010; 135:2220-32. [DOI: 10.1039/c0an00307g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zhang EJ, Ng KM, Luo KQ. Extraction and purification of isoflavones from soybeans and characterization of their estrogenic activities. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:6940-50. [PMID: 17658826 DOI: 10.1021/jf0708903] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Soybean isoflavones have multiple beneficial health effects especially on estrogen-deficient diseases such as menopausal symptoms. In this study, isoflavones were produced from soybean flour, and the extraction and purification parameters were optimized to give a high yield of total isoflavones, about 0.62 mg of aglycones/g of soybean flour, which is >2 times the initial yield. HPLC analysis and MTT cell proliferation assay using MCF-7 cells revealed that the product thus obtained not only contained a high content of isoflavone aglycones but also had estrogenic activity. MTT data also revealed that both genistein and daidzein exhibited estrogenic effects at lower concentrations and antiproliferative effects at higher concentrations, and 1 microM genistein and 10 microM daidzein exerted significant estrogenic activities, which were not more than that of the endogenous level of 17beta-estradiol (E2). The production method developed can be used as a guideline for manufacturing soy isoflavones, and the MTT assay was demonstrated to be suitable for quality control on isoflavone products. The results on the estrogenic properties of isoflavones can be used as reference data for their effective and safe usages in estrogenic therapy.
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Affiliation(s)
- Elizabeth Jingnan Zhang
- Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, People's Republic of China
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Valcárcel M, Simonet BM, Cárdenas S. Bridging the gap between analytical R&D products and their use in practice. Analyst 2007; 132:97-100. [PMID: 17260066 DOI: 10.1039/b613017h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Identifying the key stakeholders (viz. R&D centers, routine laboratories, clients and producers of analytical tools) and their mutual relationships in Analytical Science, and pinpointing the objects through which knowledge and technology can be transferred among them, can help one recognize the weaknesses in the links connecting 'ivory towers' and industry with a view to developing ways to bridge the existing gap between the two.
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Affiliation(s)
- M Valcárcel
- Department of Analytical Chemistry, Marie Curie Annex Building, Campus de Rabanales, University of Córdoba, 14071 Córdoba, Spain.
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Barbero GF, Palma M, Barroso CG. Pressurized liquid extraction of capsaicinoids from peppers. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:3231-6. [PMID: 16637678 DOI: 10.1021/jf060021y] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A method has been developed for the extraction of capsaicinoids from peppers by pressurized liquid extraction (PLE); these compounds are determined by reverse phase high-performance liquid chromatography (HPLC), with detection by fluorescence spectrophotometry and mass spectrometry (MS). The stability of capsaicin and dihydrocapsaicin has been studied at different temperatures (50-200 degrees C), and several extraction variables have been assayed: solvent (methanol, ethanol, and water), different percentages of water in the methanol (0-20%) and in the ethanol (0-20%), and the number of extraction cycles. The study has evaluated the repeatability (RSD < 7%) and the reproducibility (RSD < 7%) of the method. Finally, the PLE method developed has been applied to quantify the capsaicinoids present in three varieties of hot peppers cultivated in Spain, quantifying five capsaicinoids: nordihydrocapsaicin, capsaicin, dihydrocapsaicin, an isomer of dihydrocapsaicin, and homodihydrocapsaicin.
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Affiliation(s)
- Gerardo F Barbero
- Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cadiz, Apartado 40, 11510 Puerto Real, Cadiz, Spain
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Simonet B, Lendl B, Valcárcel M. Method-defined parameters: measurands sometimes forgotten. Trends Analyt Chem 2006. [DOI: 10.1016/j.trac.2005.09.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Martínez Montero C, Rodríguez Dodero MDC, Guillén Sánchez DA, García Barroso C. Sugar contents of Brandy de Jerez during its aging. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2005; 53:1058-1064. [PMID: 15713020 DOI: 10.1021/jf0403078] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Brandy de Jerez is aged in American oak casks according to the traditional dynamic system (Soleras y Criaderas) and sometimes additionally by the static system (Anadas). The experimental arrangement used here for the analytical monitoring of brandy aging consisted of 15 casks, 12 of which were set up for aging by the dynamic system, which is well established in the denomination of origin area, whereas the other 3 contained the same brandy but aged according to the static system. This paper studies the kinetics of sugar extraction from oak wood to distillate, as well as the possible correlations between the sugar contents in brandy and its age or the commercial type it belongs to (Solera, Solera Reserva, or Solera Gran Reserva). High-performance anion-exchange chromatography with pulsed amperometric detection was used as the analytical tool to measure the concentrations of glucose, fructose, arabinose, galactose, and xylose, the presence of which in brandy has previously been described.
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Affiliation(s)
- Cristina Martínez Montero
- Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz C/República Saharaui s/n, 11510 Puerto Real, Cádiz, Spain.
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Alonso AM, Guillén DA, Barroso CG, Puertas B, García A. Determination of antioxidant activity of wine byproducts and its correlation with polyphenolic content. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:5832-5836. [PMID: 12358446 DOI: 10.1021/jf025683b] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
It has been demonstrated that wine and other products derived from the grape have a high antioxidant capability; as a possible consequence of this, they may have potential benefits for health. The byproducts of the winemaking process represent a source of antioxidant compounds that has been relatively unexploited to date, but that is now the subject of increasing industrial interest. This article describes an approach to the study of the antioxidant activity of grape marcs, stalks, and dregs of both white and red varieties. This activity is compared with the measurements of their content of total polyphenols and of individual polyphenolic compounds, identified and quantified by HPLC. From the results we have been able to establish a positive correlation between the antioxidant activity and the total polyphenolic content of samples, but not with specific compounds.
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Affiliation(s)
- Angeles M Alonso
- Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, C/República Saharaui s/n, 11510 Puerto Real, Cádiz, Spain.
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Alonso AM, Domínguez C, Guillén DA, Barroso CG. Determination of antioxidant power of red and white wines by a new electrochemical method and its correlation with polyphenolic content. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:3112-3115. [PMID: 12009971 DOI: 10.1021/jf0116101] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new method for measuring the antioxidant power of wine has been developed based on the accelerated electrochemical oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). The calibration (R = 0.9922) and repeatability study (RSD = 7%) have provided good statistical parameters. The method is easy and quick to apply and gives reliable results, requiring only the monitoring of time and absorbance. It has been applied to various red and white wines of different origins. The results have been compared with those obtained by the total antioxidant status (TAS) method. Both methods reveal that the more antioxidant wines are those with higher polyphenolic content. From the HPLC study of the polyphenolic content of the same samples, it is confirmed that there is a positive correlation between the resveratrol content of a wine and its antioxidant power.
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Affiliation(s)
- Angeles M Alonso
- Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, C/República Saharaui, s/n. 11510 Puerto Real, Cádiz, Spain.
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Palma M, Taylor LT. Supercritical fluid extraction of 5-hydroxymethyl-2-furaldehyde from raisins. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2001; 49:628-632. [PMID: 11262003 DOI: 10.1021/jf001070s] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
An extraction method based on supercritical CO(2) has been developed for the analysis of 5-hydroxymethyl-2-furaldehyde in raisins. To optimize extraction variables, a fractional factorial experimental design was applied. Six extraction variables were optimized. The organic modifier used for increasing the extraction fluid solvating power was the most important factor. Methanol as organic modifier produced 10-fold higher recoveries of 5-hydroxymethyl-2-furaldehyde than ethyl acetate. The efficiency of the organic modifier in the static extraction phase was compared with using it in the dynamic extraction phase. Repeatability of the analysis method was evaluated, which resulted in an RSD of <5%. 5-Hydroxymethyl-2-furaldehyde was quantified in raisins, and the concentration was found to be 0.128 mg/g of raisin.
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Affiliation(s)
- M Palma
- Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
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Valcárcel M, Gallego M, Cárdenas S. Sample/analyte screening systems and chromatography. Chromatographia 2001. [DOI: 10.1007/bf02490321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
A direct, completely automated calibration procedure in capillary electrophoresis (CE) is presented. The manual calibration operations involved in analytical methods, such as external calibration, standard addition, and internal standard, were accomplished with a continuous flow system (CFS) coupled to commercial capillary electrophoresis equipment via a programmable arm. The system was managed by the proper CE microprocessor and allowed automatic calibration and direct quantification of the analytes in the sample without any manual pretreatment, therefore avoiding or minimizing manually associated errors. The whole system including peristaltic pumps and the programmable arm was connected via an electronic interface and completely controlled by a computer using a program written in GW-BASIC. The potential of this new CFS-CE arrangement was assessed by applying it to samples containing selected compounds.
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Affiliation(s)
- L Arce
- Analytical Chemistry Division, Faculty of Sciences, University of Córdoba, Spain
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