Search results for " Analytic"
showing 10 items of 1718 documents
Exposure of the Croatian adult population to acrylamide through bread and bakery products
2019
The aim of the present study was to determine and compare the levels of acrylamide in different types of bread and bakery products using a LC– MS/MS method, before and after the new European regulation on acrylamide reduction (Commission Regulation (EU) 2017/2158) became valid. Also, one of the aim was to estimate the average exposure to acrylamide through this food category. Of the total of 100 analysed samples, acrylamide content ranged from below the limit of quantification (LOQ) to 237 μg/kg in the period before the application of a new European Regulation, and from <LOQ to 42 μg/kg after it's application. For the adult Croatian population the dietary mean exposure to acrylamide in brea…
Mycotoxin Analysis of Human Urine by LC-MS/MS: A Comparative Extraction Study
2017
The lower mycotoxin levels detected in urine make the development of sensitive and accurate analytical methods essential. Three extraction methods, namely salting-out liquid–liquid extraction (SALLE), miniQuEChERS (quick, easy, cheap, effective, rugged, and safe), and dispersive liquid–liquid microextraction (DLLME), were evaluated and compared based on analytical parameters for the quantitative LC-MS/MS measurement of 11 mycotoxins (AFB1, AFB2, AFG1, AFG2, OTA, ZEA, BEA, EN A, EN B, EN A1 and EN B1) in human urine. DLLME was selected as the most appropriate methodology, as it produced better validation results for recovery (79–113%), reproducibility (RSDs < 12%), and repeatability (RSDs…
Ultra-Performance Liquid Chromatography-Ion Mobility Separation-Quadruple Time-of-Flight MS (UHPLC-IMS-QTOF MS) Metabolomics for Short-Term Biomarker…
2020
A major problem with dietary assessments is their subjective nature. Untargeted metabolomics and new technologies can shed light on this issue and provide a more complete picture of dietary intake by measuring the profile of metabolites in biological samples. Oranges are one of the most consumed fruits in the world, and therefore one of the most studied for their properties. The aim of this work was the application of untargeted metabolomics approach with the novel combination of ion mobility separation coupled to high resolution mass spectrometry (IMS-HRMS) and study the advantages that this technique can bring to the area of dietary biomarker discovery, with the specific case of biomarker…
Mycotoxin Occurrence and Risk Assessment in Gluten-Free Pasta through UHPLC-Q-Exactive Orbitrap MS
2021
Celiac disease (CD) is a genetic-based autoimmune disorder which is characterized by inflammation in the small intestinal mucosa due to the intolerance to gluten. Celiac people should consume products without gluten, which are elaborated mainly with maize or other cereals. Contamination of cereals with mycotoxins, such as fumonisins (FBs) and aflatoxins (AFs) is frequently reported worldwide. Therefore, food ingestion is the main source of mycotoxin exposure. A new analytical method was developed and validated for simultaneous analysis of 21 mycotoxins in gluten-free pasta, commonly consumed by celiac population as an alternative to conventional pasta. Ultrahigh-performance liquid chromatog…
Inter-individual variation of the urinary steroid profiles in Swedish and Norwegian athletes.
2020
The steroidal module of the Athlete Biological Passport (ABP) aims to detect doping with endogenous steroids, e.g. testosterone (T), by longitudinally monitoring several biomarkers. These biomarkers are ratios combined into urinary concentrations of testosterone and metabolically related steroids. However, it is evident after 5 years of monitoring steroid passports that there are large variations in the steroid ratios complicating its interpretation. In this study, we used over 11000 urinary steroid profiles from Swedish and Norwegian athletes to determine both the inter- and intra-individual variations of all steroids and ratios in the steroidal passport. Furthermore, we investigated if th…
Cocaine abuse determination by ion mobility spectrometry using molecular imprinting
2016
A cocaine-based molecular imprinted polymer (MIP) has been produced by bulk polymerization and employed as selective solid-phase extraction support for the determination of cocaine in saliva samples by ion mobility spectrometry (IMS). The most appropriate conditions for washing and elution of cocaine from MIPs were studied and MIPs were characterized in terms of analyte binding capacity, reusability in water and saliva analysis, imprinting factor and selectivity were established and compared with non-imprinted polymers. The proposed MIP-IMS method provided a LOD of 18μgL-1 and quantitative recoveries for blank saliva samples spiked from 75 to 500μgL-1 cocaine. Oral fluid samples were collec…
Accident ahead? Difficulties of drivers with and without reading impairment recognising words and pictograms in variable message signs
2017
A timely and accurate acquisition of the information provided by variable message signs (VMS) can be crucial while driving. In the current study, we assess the difficulties of adults with dyslexia acquiring the information shown in VMS and provide evidence to discuss the controversial use of pictograms as potential countermeasures. Twenty-two adults with dyslexia and 22 matched controls completed a simulated driving session. The legibility of 12 VMS was assessed, including six text messages (e.g. "ACCIDENT") and six single pictograms (e.g. the icon for "accident ahead"). On average, participants with dyslexia started reading text messages when they were closer to the VMS. In addition, while…
Magnetic molecularly imprinted polymers for the selective determination of cocaine by ion mobility spectrometry
2018
Abstract Magnetic molecularly imprinted polymers (MMIPs) were prepared for cocaine recognition by bulk polymerization in the presence of magnetic nanoparticles (MNPs). Two reagents (polyethylene glycol (PEG) and 3-(trimethoxysilyl)propyl methacrylate (V)) were used for MNPs modification. MMIPs were characterized and compared in terms of loading capacity, reusability, accuracy and precision for the extraction of cocaine from saliva samples. It was observed that V-MMIPs gave higher physical stability than PEG-MMIPs. Thus, V-MMIP were used for the analysis of cocaine users saliva. The developed procedure based on ion mobility spectrometry (IMS) provided limits of detection and quantification o…
A new approach to examine the relationships between sensory and gas chromatography-olfactometry data using generalized procrustes analysis applied to…
2003
Six French Chardonnay wines were submitted to both sensory and combined headspace/gas chromatography-olfactometry analyses. The detection frequencies allowed five hierarchical levels to be distinguished: P25, the odorant areas (OAs) having a detection frequencyor =25% (the complete olfactogram without the odor noise); P40,or =40%; P55,or =55%; P70,or =70%; and P85,or =85%. Moreover, the detection frequencies were analyzed to distinguish 21 discriminative OAs. Wines tested by sensory analysis and the headspace samples analyzed by gas chromatography-olfactometry (GC-O) were described by a heterogeneous vocabulary distributed into nine overall classes of descriptors. The new statistical treatm…
The shift from monologue to dialogue in a couple therapy session: dialogical investigation of change from the therapists' point of view.
2012
As part of a larger research project on couple therapy for depression, this qualitative case study examines the nature of dialogue. Drawing on Bakhtinian concepts, the investigation shows how the conversation shifts from a monologue to dialogue. Among the findings are: first, the process of listening is integral to the transforming experience. That is, the careful listening of the therapist can evoke new voices, just as the experience of one of the partners' "listening in" to the conversation between the other partner and the therapist can create movement and new trajectories. The latter is a qualitative difference between dialogic therapy with a couple and that with an individual. Second, …