Development and validation of a WD‐XRF method for quantitative trace analysis: Application in the food industry

2020 ◽  
Author(s):  
María Fernanda Gazulla ◽  
Marta Rodrigo ◽  
María Jesús Ventura ◽  
Mónica Orduña ◽  
Cristina Andreu
1997 ◽  
Vol 26 (5) ◽  
pp. 272-274 ◽  
Author(s):  
José Antonio Gásquez ◽  
Ernesto Perino ◽  
Eduardo Marchevsky ◽  
Roberto Olsina ◽  
Alberto Riveros

2021 ◽  
pp. 073563312199259
Author(s):  
Meng-Jung Tsai ◽  
Ching-Yeh Wang ◽  
An-Hsuan Wu ◽  
Chun-Ying Hsiao

Robotics education has gradually been emphasized in contemporary school curricula; however, assessment tools for robotics learning are still limited. Based on Bloom’s Taxonomy of educational objectives, this study aimed to develop the Robotics Learning Self-Efficacy Scale (RLSES) with a two-level construct of five dimensions for assessing students’ self-efficacy for learning robotics. A total of 181 elementary, junior high and senior high school students (5th–12th graders) with robotics learning experience were selected as the sample of this study. A questionnaire including 32 candidate items designed for the initial version of the RLSES was administered to the sample. An exploratory factor analysis was conducted and, finally, 16 items were drawn for the final RLSES under five subscales ( Comprehension, Practice, Analysis, Application, and Collaboration), with a total explained variance of 85.28%. The Cronbach’s alpha reliability was .97 for the overall scale, ranging from .87 to .95 for the subscales. The inter-correlation analysis showed evidence of discriminant validity. Regression analysis results supported that Practice and Comprehension self-efficacy were significant predictors of Analysis, Application, and Collaboration self-efficacy, confirming the two-level (2 × 3) construct of the RLSES. Significant differences among school levels were found and are discussed.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Josilene Chaves Ruela Corrêa ◽  
Cristina Duarte Vianna-Soares ◽  
Hérida Regina Nunes Salgado

The purpose of this study is to develop and validate a dissolution test for fluconazole, an antifungal used for the treatment of superficial, cutaneous, and cutaneomucous infections caused by Candida species, in capsules dosage form. Techniques by HPLC and UV first derivative spectrophotometry (UV-FDS) were selected for quantitative evaluation. In the development of release profile, several conditions were evaluated. Dissolution test parameters were considered appropriate when a most discriminative release profile for fluconazole capsules was yielded. Dissolution test conditions for fluconazole capsules were 900 mL of HCl 0.1 M, 37 ± 0.5 °C using baskets with 50 rpm for 30 min of test. The developed HPLC and UV-FDS methods for the antifungal evaluation were selective and met requirements for an appropriate and validated method, according to ICH and USP requirements. Both methods can be useful in the registration process of new drugs or their renewal. For routine analysis application cost, simplicity, equipment, solvents, speed, and application to large or small workloads should be observed.


2011 ◽  
Vol 94 (3) ◽  
pp. 775-785 ◽  
Author(s):  
Maria Rambla-Alegre ◽  
Josep Esteve-Romero ◽  
Samuel Carda-Broch

Abstract Antibiotics are the most important bioactive and chemotherapeutic compounds to be produced by microbiological synthesis, and they have proved their worth in a variety of fields, such as medicinal chemistry, agriculture, and the food industry. Interest in antibiotics has grown in parallel with an increasingly high degree of productivity in the field of analytical applications. Therefore, it is necessary to develop chromatographic procedures capable of determining various drugs simultaneously in the shortest possible time. Micellar liquid chromatography (MLC) is an RP-HPLC technique that offers advantages over conventional HPLC as far as sample preparation, selectivity, and versatility are concerned. Its main advantage is that samples can be injected directly into the chromatographic system with no previous preparation step. This paper mainly focuses on the results of the authors' own recent research and reports the chromatographic conditions for determination of various antibiotics (penicillins, quinolones, and sulfonamides) in different matrixes (pharmaceuticals, biological fluids, and food). The work of other authors on MLC-based antibiotic determination has been included.


2019 ◽  
Vol 8 (3) ◽  
pp. 71 ◽  
Author(s):  
Dimitra Houhoula ◽  
Spiridon Andreas Papatheodorou ◽  
Dimitra Moschou ◽  
Sofia Pappa ◽  
Nikolaos Tsaatazoglou ◽  
...  

Food allergens are a well acknowledged issue in food industry and are regulated by legislation. The presence of allergens can either origin from the raw material or due to contamination during production. Allergen information on packaging is mandatory although it cannot be accurate in the case of contamination therefore warnings are used. The purpose of the study is the development and validation of a SYBR Green Real Time Polymerase Chain Reaction method using specific primer pairs based on Jug r 1, Jug r 3, and Jug r 4 allergen-coding sequences to improve the sensitivity of Real Time Polymerase Chain Reaction techniques for detection of walnut and almond traces in commercial food products and its comparison with ELISA methodology in terms of detection ability. A total of 100 samples were collected from local markets and were analyzed by Real Time Polymerase Chain Reaction (RT-PCR) and ELISA methods. The results indicated that 16 samples (16%) were found positive in walnut traces and 18 samples (18%) were found positive in almond traces by Real Time Polymerase Chain Reaction of which Elisa identified 14 samples (14%) positive in walnut traces and 15 samples (15%) positive in almond traces. Among them, 4 samples (25%) that contained walnut traces and 6 samples (33.3%) that contained almond traces had no allergen declaration on their label. The improved accuracy of Real Time Polymerase Chain Reaction underlines the importance of this method for allergen detection and quantification in the food industry


Author(s):  
Jean Fincher

An important trend in the food industry today is reduction in the amount of fat in manufactured foods. Often fat reduction is accomplished by replacing part of the natural fat with carbohydrates which serve to bind water and increase viscosity. It is in understanding the roles of these two major components of food, fats and carbohydrates, that freeze-fracture is so important. It is well known that conventional fixation procedures are inadequate for many food products, in particular, foods with carbohydrates as a predominant structural feature. For some food science applications the advantages of freeze-fracture preparation procedures include not only the avoidance of chemical fixatives, but also the opportunity to control the temperature of the sample just prior to rapid freezing.In conventional foods freeze-fracture has been used most successfully in analysis of milk and milk products. Milk gels depend on interactions between lipid droplets and proteins. Whipped emulsions, either whipped cream or ice cream, involve complex interactions between lipid, protein, air cell surfaces, and added emulsifiers.


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