Search results for " Analytic"
showing 10 items of 1718 documents
Analytical strategies for organic food packaging contaminants
2016
In this review, we present current approaches in the analysis of food-packaging contaminants. Gas and liquid chromatography coupled to mass spectrometry detection have been widely used in the analysis of some relevant families of these compounds such as primary aromatic amines, bisphenol A, bisphenol A diglycidyl ether and related compounds, UV-ink photoinitiators, perfluorinated compounds, phthalates and non-intentionally added substances. Main applications for sample treatment and different types of food-contact material migration studies have been also discussed. Pressurized Liquid Extraction, Solid-Phase Microextraction, Focused Ultrasound Solid-Liquid Extraction and Quechers have been …
Determination of Phenolic Endocrine Disruptors in Cosmetics by High-Performance Liquid Chromatography Mass Spectrometry
2017
An analytical method for the simultaneous determination of bisphenol A, 4-t-octylphenol, 4-n-octylphenol, and 4-n-nonylphenol in cosmetic samples has been developed. These compounds have toxic effe...
An automatic flow-through system for exploration of the human bioaccessibility of endocrine disrupting compounds from microplastics
2021
This article reports on the first attempt towards investigating the leaching rates in the human gastrointestinal (GI) tract of plastic-borne contaminants that can be ingested accidentally using physiologically relevant body fluids. Oral bioaccessibility under fasted and fed states was determined in dynamic mode exploiting an automatic flow setup. The flow system is able to mimic the fast uptake of the released species from the polymeric matrix by absorption in the human digestive system by the in-line removal of the leached species. Complex GI extractants based on the Unified Bioaccessibility Method (UBM, fasted state) and Versantvoort test (fed-state) were brought through a microplastic-lo…
Blended Learning als Spielfeld für Learning Analytics und Educational Data Mining
2020
Der Einsatz digitaler Lernformate im Blended Learning bietet demnach Chancen in mindestens zwei Bereichen. Zum einen konnen digitale Lernformate direkt die Lernprozesse von Studierenden gunstig beeinflussen, ihre Leistungen verbessern und zudem positive Effekte auf vielen weiteren Ebenen wie der Motivation oder des Selbstkonzeptes bewirken. Zum anderen generieren digitale Lernformate eine Fulle von Daten in vielfaltiger Gestalt. Studierende erzeugen bei der Arbeit mit digitalen Werkzeugen Nutzungsdaten, wie Verweildauern und Aktivitatsprofile, sie produzieren Leistungsdaten aus digitalen Aufgaben, sie hinterlassen Textbeitrage in Foren und Chats. All diese Daten konnen genutzt werden, um mi…
Noncontact speckle-based optical sensor for detection of glucose concentration using magneto-optic effect
2016
We experimentally verify a speckle-based technique for noncontact measurement of glucose concentration in the bloodstream. The final device is intended to be a single wristwatch-style device containing a laser, a camera, and an alternating current (ac) electromagnet generated by a solenoid. The experiments presented are performed in vitro as proof of the concept. When a glucose substance is inserted into a solenoid generating an ac magnetic field, it exhibits Faraday rotation, which affects the temporal changes of the secondary speckle pattern distributions. The temporal frequency resulting from the ac magnetic field was found to have a lock-in amplification role, which increased the observ…
A Multiple Local Models Approach to Accuracy Improvement in Continuous Glucose Monitoring
2011
Continuous glucose monitoring (CGM) devices estimate plasma glucose (PG) from measurements in compartments alternative to blood. The accuracy of currently available CGM is yet unsatisfactory and may depend on the implemented calibration algorithms, which do not compensate adequately for the differences of glucose dynamics between the compartments. Here we propose and validate an innovative calibration algorithm for the improvement of CGM performance.CGM data from GlucoDay(®) (A. Menarini, Florence, Italy) and paired reference PG have been obtained from eight subjects without diabetes during eu-, hypo-, and hyperglycemic hyperinsulinemic clamps. A calibration algorithm based on a dynamic glo…
Passive exposure to nicotine from e-cigarettes
2016
A procedure based on the use of ion mobility spectrometry (IMS), after liquid-liquid microextraction (LLME), has been successfully employed for the determination of passive exposure to nicotine from cigarette and e-cigarette smoking. Nicotine has been determined in exhaled breath and oral fluids of both, active and passive smokers. The aforementioned studies, made in closed environments, evidenced that the exhaled breath after conventional blend cigarette smoke provides nicotine levels of the order of 220 ng per puff, in the case of experienced smokers, being exhaled only 32 ng in the case of e-cigarettes. On the other hand, the nicotine amount in oral fluids of passive vapers was between 8…
Varietal and geographic classification of french red wines in terms of elements, amino acids and aromatic alcohols
1988
Thirty-four French red wines from three regions already studied for their anthocyanin and flavonoid constituents have been further analysed for elements, amino acids and aromatic alcohols. An interpretation of the differences between wines related to their different geographic and varietal origins has been made from the results of statistical analyses: F statistic, principal component analysis (PCA) and stepwise discriminant analysis (SDA). Wine samples produced near Bordeaux were found to be characterised by higher rubidium and lower lithium and calcium concentrations. Differences between wine samples made from the same grape variety or produced in the same region are mainly related to dif…
A new chromo-fluorogenic probe based on BODIPY for NO2 detection in air
2014
[EN] A novel colorimetric probe for the selective and sensitive detection of NO2 in solution and in air based on a BODIPY core containing an oxime group has been prepared.
Perfluoroalkyl substances in Breast milk, infant formula and baby food from Valencian Community (Spain)
2016
Environmental and human exposures to perfluoroalkyl substances (PFASs) are of emerging concern since they are persistent and bioaccumulative. The present study reports PFASs levels in human milk, infant formulas and baby food (dry cereals and pots) from the Valencian Community (Spain) in order to evaluate the infant exposure to these substances through the diet. The results show that perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) were in all the samples of the four selected matrices (except PFOA in one sample of dry cereal baby food). Perfluoroheptanoic acid (PFHpA) and perfluorodecanoic acid (PFDA) were also detected in 70% of the breast milk samples. In infant formulas, P…