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Winquist, Fredrik
Alternative names
Publications (10 of 60) Show all publications
Cavanillas, S., Winquist, F. & Eriksson, M. (2015). A self-polishing platinum ring voltammetric sensor and its application to complex media. Analytica Chimica Acta, 859, 29-36
Open this publication in new window or tab >>A self-polishing platinum ring voltammetric sensor and its application to complex media
2015 (English)In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 859, p. 29-36Article in journal (Refereed) Published
Abstract [en]

A self-polishing voltammetric sensor was recently developed and has been applied to samples of urea, milk and sewage water. The polishing device continuously grinds a platinum ring electrode, offering a reproducible and clean electrode surface. Principal component analysis (PCA) and partial least squares (PLS) techniques were applied to interpret the data and to build prediction models. In an evaluation of samples with different urea concentrations, the grinding step allows for repeatable measurements, similar to those after electrochemical cleaning. Furthermore, for the determination of sewage water concentrations in drinking water and for the evaluation of different fat contents in milk samples, the polishing eliminates sensor drift produced by electrode fouling. The results show that the application of a self-polishing unit offers a promising tool for electrochemical studies of difficult analytes and complex media. (C) 2014 Elsevier B.V. All rights reserved.

Place, publisher, year, edition, pages
Elsevier Masson, 2015
Keywords
Voltammetric sensor; Electronic tongue; Urea; Milk; Drinking water; Sewage water
National Category
Biological Sciences Physical Sciences
Identifiers
urn:nbn:se:liu:diva-114563 (URN)10.1016/j.aca.2014.11.039 (DOI)000348457300003 ()25622603 (PubMedID)
Note

Funding Agencies|MICINN [BES-2010-032352]

Available from: 2015-03-02 Created: 2015-02-26 Last updated: 2017-12-04
Schmekel, B., Winquist, F. & Vikström, A. (2014). Analysis of breath samples for lung cancer survival. Analytica Chimica Acta, 840, 82-86
Open this publication in new window or tab >>Analysis of breath samples for lung cancer survival
2014 (English)In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 840, p. 82-86Article in journal (Refereed) Published
Abstract [en]

Analyses of exhaled air by means of electronic noses offer a large diagnostic potential. Such analyses are non-invasive; samples can also be easily obtained from severely ill patients and repeated within short intervals. Lung cancer is the most deadly malignant tumor worldwide, and monitoring of lung cancer progression is of great importance and may help to decide best therapy. In this report, twenty-two patients with diagnosed lung cancer and ten healthy volunteers were studied using breath samples collected several times at certain intervals and analysed by an electronic nose. The samples were divided into three sub-groups; group d for survivor less than one year, group s for survivor more than a year and group h for the healthy volunteers. Prediction models based on partial least square and artificial neural nets could not classify the collected groups d, s and h, but separated well group d from group h. Using artificial neural net, group d could be separated from group s. Excellent predictions and stable models of survival day for group d were obtained, both based on partial least square and artificial neural nets, with correlation coefficients 0.981 and 0.985, respectively. Finally, the importance of consecutive measurements was shown.

Place, publisher, year, edition, pages
Elsevier Masson, 2014
Keywords
Breath analysis; Electronic nose; Lung cancer; Survival prediction
National Category
Clinical Medicine Biological Sciences
Identifiers
urn:nbn:se:liu:diva-109871 (URN)10.1016/j.aca.2014.05.034 (DOI)000339992500011 ()25086897 (PubMedID)
Note

Funding Agencies|County Council of Ostergotland

Available from: 2014-08-28 Created: 2014-08-28 Last updated: 2017-12-05
Vagin, M., Sekretareva, A., Sanchez, R., Lundström, I., Winquist, F. & Eriksson, M. (2014). Arrays of Screen-Printed Graphite Microband Electrodes as a Versatile Electroanalysis Platform. ChemElectroChem, 1(4), 755-762
Open this publication in new window or tab >>Arrays of Screen-Printed Graphite Microband Electrodes as a Versatile Electroanalysis Platform
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2014 (English)In: ChemElectroChem, ISSN 2196-0216, Vol. 1, no 4, p. 755-762Article in journal (Refereed) Published
Abstract [en]

Arrays of microband electrodes were developed by screen printing followed by cutting, which enabled the realization of microband arrays at the cut edge. The microband arrays of different designs were characterized by physical and electro-chemical methods. In both cases, the methods showed that the microband width was around 5 mm. Semi-steady-state cyclic voltammetry responses were observed for redox probes, and chronocoulometric measurements showed the establishment of convergent diffusion regimes characterized by current densities similar to those of a single microelectrode. The analytical performance of the electrode system and its versatility were illustrated with two electrochemical assays: detection of ascorbic acid through direct oxidation and a mediated glucose biosensor fabricated by dip coating. Due to convergent mass transport, both systems showed an enhancement in their analytical characteristics. The developed approach can be adapted to automated electrode recovery.

Place, publisher, year, edition, pages
Wiley, 2014
Keywords
graphite screen printing; microarrays; microband; sensors; voltammetry
National Category
Physical Sciences Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-109289 (URN)10.1002/celc.201300204 (DOI)000338296100010 ()
Available from: 2014-08-11 Created: 2014-08-11 Last updated: 2017-11-03Bibliographically approved
Eriksson, M., Lindgren, D., Bjorklund, R., Winquist, F., Sundgren, H. & Lundström, I. (2011). Drinking water monitoring with voltammetric sensors. Paper presented at Eurosensors XXV, September 4-7, 2011, Athens, Greece. Procedia Engineering, 25, 1165-1168
Open this publication in new window or tab >>Drinking water monitoring with voltammetric sensors
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2011 (English)In: Procedia Engineering, ISSN 1877-7058, E-ISSN 1877-7058, Vol. 25, p. 1165-1168Article in journal (Refereed) Published
Abstract [en]

Pulsed voltammetry has been applied to drinking water monitoring. This non-selective technique facilitates detection of several different threats to the drinking water. A multivariate algorithm shows that anomaly detection is possible with a minimum of false alarms. Multivariate analysis can also be used to classify different types of substances added to the drinking water. Low concentrations of sewage water contaminating the drinking water can be detected. A network of such sensors is envisaged to facilitate real-time and on-line monitoring of drinking water distribution networks.

Place, publisher, year, edition, pages
Elsevier, 2011
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:liu:diva-118323 (URN)10.1016/j.proeng.2011.12.287 (DOI)
Conference
Eurosensors XXV, September 4-7, 2011, Athens, Greece
Available from: 2015-05-27 Created: 2015-05-27 Last updated: 2017-12-04
Winquist, F., Olsson, J. & Eriksson, M. (2011). Multicomponent analysis of drinking water by a voltammetric electronic tongue. Analytica Chimica Acta, 683(2), 192-197
Open this publication in new window or tab >>Multicomponent analysis of drinking water by a voltammetric electronic tongue
2011 (English)In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 683, no 2, p. 192-197Article in journal (Refereed) Published
Abstract [en]

A voltammetric electronic tongue is described that was used for multicomponent analysis of drinking water. Measurements were performed on drinking water from a tap and injections of the compounds NaCl, NaN3, NaHSO3, ascorbic acid, NaOCl and yeast suspensions could be identified. A PLS based model was developed for the simultaneously prediction of identification and concentration of the compounds NaCl, NaHSO3 and NaOCl .By utilizing this type of nonselective sensor technique for water quality surveillance, it will be feasible to detect a plurality of events without the need of a specific sensor for each type of event.

Place, publisher, year, edition, pages
Elsevier, 2011
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-65410 (URN)10.1016/j.aca.2010.10.027 (DOI)000286854700006 ()
Available from: 2011-02-07 Created: 2011-02-07 Last updated: 2017-12-11
Forsgren, G., Winquist, F. & Öström, Å. (2010). Analysis of volatile compounds of aqueous thyme solutions by headspace gas chromatography, gas sensor arrays ("electronic nose") and a sensory odour panel.
Open this publication in new window or tab >>Analysis of volatile compounds of aqueous thyme solutions by headspace gas chromatography, gas sensor arrays ("electronic nose") and a sensory odour panel
2010 (English)Article in journal (Other academic) Submitted
Abstract [en]

The ability of a commercial emission analysis system to evaluate a sensory related attribute was investigated. Since food applications are very complex, a simplified model system consisting of aqueous thyme solutions was evaluated. Sensory odour assessments were made as well as instrumental analysis applying the emission analyser, based on gas sensor arrays, (a so called electronic nose) and headspace gas chromatography. The operation of the emission analyser was found critical and could be optimised thanks to the detailed chemical information obtained by the chromatography. This information also guided a proper evaluation of the emission analyser raw data and predictions of the relative thyme concentrations of the solutions. In that way the emission analyser separated the thyme solutions even better than the assessors applying sensory odour analysis. Since the results seem encouraging the strategy developed and knowledge gained may well be used for investigating more complex systems closer to real applications.

Keywords
Thyme, water, volatiles, sensory analysis, electronic nose, gas chromatography
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-17333 (URN)
Available from: 2009-03-19 Created: 2009-03-19 Last updated: 2010-04-19Bibliographically approved
Bjorklund, R., Magnusson, C., Martensson, P., Winquist, F. & Krantz-Rülcher , C. (2009). Continuous monitoring of yoghurt fermentation using a noble metal electrode array. International Journal of Food Science and Technology, 44(3), 635-640
Open this publication in new window or tab >>Continuous monitoring of yoghurt fermentation using a noble metal electrode array
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2009 (English)In: International Journal of Food Science and Technology, ISSN 0950-5423, Vol. 44, no 3, p. 635-640Article in journal (Refereed) Published
Abstract [en]

An electrochemical probe containing gold, platinum and rhodium working electrodes was used to monitor yoghurt production in a pilot facility. Three commercial starting cultures at 40, 42 and 44 C transformed milk having 1.5% fat content to mild yoghurt products. The electrochemical changes in the broth during fermentation were recorded as current responses from pulse voltammetry over the electrodes. Principal component analysis of the responses generated two-dimensional score plots describing the qualitative fermentation progressions. Two distinct fermentation pathways were observed leading to similar final products. The pH was recorded during the fermentations and the data was used as reference values for creating a partial least squares model for prediction of pH as an example of a quantitative application for the sensor. The relative mean squared error for validation of the model using four probes interchangeably was about 2%. The probe was constructed of materials approved for use in the food industry and did not require a standard glass reference electrode.

Keywords
Multivariate analysis; pH; Process monitoring; Voltammetry; Yoghurt
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-18833 (URN)10.1111/j.1365-2621.2008.01886.x (DOI)
Available from: 2009-06-05 Created: 2009-06-05 Last updated: 2009-06-05
H Labrador, R., Olsson, J., Winquist, F., Martinez-Manez, R. & Sotoa, J. (2009). Determination of Bisulfites in Wines with an Electronic Tongue Based on Pulse Voltammetry. Electroanalysis, 21(3-5), 612-617
Open this publication in new window or tab >>Determination of Bisulfites in Wines with an Electronic Tongue Based on Pulse Voltammetry
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2009 (English)In: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 21, no 3-5, p. 612-617Article in journal (Refereed) Published
Abstract [en]

An electronic tongue (ET) based on pulse voltammetry is used to predict concentrations of bisulfites in wine samples. The ET array consists of four working electrodes (gold, rhodium, platinum and stainless steel) encapsulated into a stainless steel cylinder used at the same time as both the body of the ET system and the pseudoreference/counter electrode. The ET device is additionally equipped with a self-polishing system. Multivariate analysis including Cross validation and partial least square (PLS) techniques are applied for data management and prediction models building. Ascorbic acid and histamine have also been included in the predictive analysis.

Keywords
Electronic tongue, Pulse voltammetry, Bisulfite, Prediction model, PLS
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-17513 (URN)10.1002/elan.200804457 (DOI)
Available from: 2009-03-27 Created: 2009-03-27 Last updated: 2017-12-13
Eriksson, M., Winquist, F., Bjorklund, R., Lindgren, D., Sundgren, H. & Lundström, I. (2009). Event Detection in Crisis Management Systems. Paper presented at Proceedings of the Eurosensors XXIII Conference. Procedia Chemistry, 1(1), 1055-1058
Open this publication in new window or tab >>Event Detection in Crisis Management Systems
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2009 (English)In: Procedia Chemistry, ISSN 1876-6196, E-ISSN 1876-6196, Vol. 1, no 1, p. 1055-1058Article in journal (Refereed) Published
Abstract [en]

The EVENT project concerns drinking water surveillance and includes sensors and algorithms that detect anomalies in the drinking water properties, communication of the evaluated sensor data to a crises management system and presentation of information that is relevant for the end users of the crises management system. We have chosen to focus on a sensor technique based on an "electronic tongue", since this robust type of non-selective sensor, can detect a plurality of anomalies without the need of a specific sensor for each type of event. Measurements of natural variations and contamination events are presented and discussed.

Place, publisher, year, edition, pages
Elsevier, 2009
Keywords
Electronic tongue, Voltammetry, Drinking water, Surveillance, Crises management, Critical infrastructure
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-58421 (URN)10.1016/j.proche.2009.07.263 (DOI)000275995600040 ()
Conference
Proceedings of the Eurosensors XXIII Conference
Available from: 2010-08-12 Created: 2010-08-11 Last updated: 2017-12-12
Forsgren, G., Winquist, F. & Andersson, T. (2009). Flavour interactions in aqueous solutions of an aldehyde, a ketone and a carboxylic acid.
Open this publication in new window or tab >>Flavour interactions in aqueous solutions of an aldehyde, a ketone and a carboxylic acid
2009 (English)Article in journal (Other academic) Submitted
Abstract [en]

Flavour impressions of aqueous solutions of nonanoic acid, octan-2-one and octanal were investigated. In a pre-study, the psychophysical functions of single component solutions were estimated and good agreements to Fechner’s law were obtained. The findings guided the choice of concentrations used in the main flavour interaction study. In this study, binary mixture interactions of nonanoic acid – octanal and octan-2-one – octanal were investigated in terms of perceived intensity and quality. Ten assessors judged the mixture solutions for flavour intensity by applying a free magnitude estimation procedure and describing their perceived quality impressions. The five assessors who were able to describe the perceived qualities in a consistent and logic way considered both mixtures being heterogeneous. Only three assessors scored intensities of the included single component solutions well in agreement with Fechner’s law. These three assessors’ intensity scorings of the mixtures did not deviate from those of a hypothetic additive model in a clear way. The intensity scorings of most of the other assessors were strongly dominated by one of the two components whereas some assessor did not score systematic at all.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-17337 (URN)
Available from: 2009-03-19 Created: 2009-03-19 Last updated: 2009-03-19Bibliographically approved
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