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1.	Bjorklund, Robert, et al. (författare) Continuous monitoring of yoghurt fermentation using a noble metal electrode array 2009 Ingår i: International Journal of Food Science and Technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 44:3, s. 635-640 Tidskriftsartikel (refereegranskat)abstract 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.
2.	Blomquist, Axel, et al. (författare) Persistent Aspergillus fumigatus infection in cystic fibrosis : impact on lung function and role of treatment of asymptomatic colonization-a registry-based case-control study 2022 Ingår i: BMC Pulmonary Medicine. - : Springer Science and Business Media LLC. - 1471-2466. ; 22:1 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Aspergillus fumigatus is the most common filamentous fungus isolated from the airways of people with cystic fibrosis (CF). The aim of this study was to investigate how chronic A. fumigatus colonization affects lung function in people with CF, to identify risk factors for colonization, and to evaluate antifungal treatment of asymptomatic Aspergillus colonization.METHODS: Data from 2014-2018 was collected from the Swedish CF registry and medical records. Baseline data before the start of A. fumigatus colonization was compared with the two succeeding years to evaluate how colonization and treatment affected lung function and other clinical aspects.RESULTS: A total of 437 patients were included, of which 64 (14.6%) became colonized with A. fumigatus during the study period. Inhaled antibiotics was associated with A. fumigatus colonization (adjusted OR 3.1, 95% CI 1.6-5.9, p < 0.05). Fungal colonization was not associated with a more rapid lung function decline or increased use of IV-antibiotics compared to the non-colonized group, but patients with A. fumigatus had more hospital days, a higher increase of total IgE, and higher eosinophil counts. In the Aspergillus group, 42 patients were considered to be asymptomatic. Of these, 19 patients received antifungal treatment. Over the follow up period, the treated group had a more pronounced decrease in percent predicted Forced Expiratory Volume in one second (ppFEV1) compared to untreated patients (- 8.7 vs - 1.4 percentage points, p < 0.05).CONCLUSION: Inhaled antibiotics was associated with A. fumigatus colonization, but no association was found between persistent A. fumigatus and subsequent lung function decline. No obvious benefits of treating asymptomatic A. fumigatus colonization were demonstrated.
3.	Gutes, A., et al. (författare) A flow injection voltammetric electronic tongue applied to paper mill industrial waters 2006 Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 115:1, s. 390-395 Tidskriftsartikel (refereegranskat)abstract A voltammetric electronic tongue with automated operation based on the flow injection (FIA) technique was applied to the characterization of wastewaters coming from the paper mill industry. A metallic multielectrode array - formed by platinum, gold and rhodium electrodes - was employed as the detection system, while the measurements were based on large amplitude pulse voltammetry (LAPV). LAPV consisted in scans of pulses from to 0 to 1.8 V at 0.2 V steps. Five current values were recorded for each pulse, so a set of 300 current values (three electrodes × 20 pulses × five values) was recorded for each sample. Samples were first discriminated using Principal Component Analysis (PCA), while Artificial Neural Networks were used for the characterization and prediction of chemical oxygen demand, conductivity and pH. The system may be used for the quick identification and monitoring of the quality of used waters in these industrial facilities. © 2005 Elsevier B.V. All rights reserved.
4.	Holmin, Susanne, et al. (författare) Compression of electronic tongue data based on voltammetry - A comparative study 2001 Ingår i: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 76:1-3, s. 455-464 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract In this paper, three data compression methods are investigated to determine their ability to reduce large data sets obtained by a voltammetric electronic tongue without loss of information, since compressed data sets will save data storage and computational time. The electronic tongue is based on a combination of non-specific sensors and pattern recognition tools, such as principal component analysis (PCA). A series of potential pulses of decreasing amplitude are applied to one working electrode at a time and resulting current transients are collected at each potential step. Voltammograms containing up to 8000 variables are subsequently obtained. The methods investigated are wavelet transformation (WT) and hierarchical principal component analysis (HPCA). Also, a new chemical/physical model based on voltammetric theory is developed in order to extract interesting features of the current transients, revealing different information about species in solutions. Two model experiments are performed, one containing solutions of different electroactive compounds and the other containing complex samples, such as juices from fruits and tomatoes. It is shown that WT and HPCA compress the data sets without loss of information, and the chemical/physical model improves the separations slightly. HPCA is able to compress the two data sets to the largest extent, from 8000 to 16 variables. When data sets are scaled to unit variance, the separation ability improves even further for HPCA and the chemical/physical model. © 2001 Elsevier Science B.V.
5.	Holmin, Susanne, et al. (författare) Drift correction of electronic tongue responses 2001 Ingår i: Measurement science and technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 12:8, s. 1348-1354 Tidskriftsartikel (refereegranskat)abstract In this article, drift correction algorithms were used in order to remove linear drift in multivariate spaces of two data sets obtained by an electronic tongue based on voltammetry. The electronic tongue consisted of various metal electrodes (Au, Ir, Pt, Rh) combined with pattern recognition tools, such as principal component analysis. The first data set contained different types of liquid, from well defined to more complex solutions. The second data set contained different black and green teas. Component correction (CC) was compared to a simple additive correction. In CC, the drift direction of measured reference solutions in a multivariate space was subtracted from other types of solution. In additive correction, responses from reference samples were subtracted from other samples. CC showed similar or better performance in reducing drift compared to additive correction for the two data sets. The additive correction method was dependent on the fact that the differences in between samples of a reference solution were similar to the changes in between samples of other liquids, which was not the case with CC.
6.	Holmin, Susanne, et al. (författare) Investigation of Electrode Materials as Sensors in a Voltammetric Electronic Tongue 2002 Ingår i: Electroanalysis. - Weinheim, Germany : Wiley-VCH Verlagsgesellschaft. - 1040-0397 .- 1521-4109. ; 14:12, s. 839-847 Tidskriftsartikel (refereegranskat)abstract In this work different electrode materials were investigated as sensors in a voltammetric electronic tongue. Basically, the electronic tongue is based on the combination of nonspecific sensors (electrodes) and pattern recognition tools, for example principal component analysis (PCA). Copper. glassy carbon, nickel, palladium, silver, tin, titanium and zirconium together with more traditional electrode materials such as gold, iridium, and platinum were studied. Cyclic voitammetry was applied to study typical model reactions in solutions containing different electroactive compounds, like ascorbic acid, glucose, histidine and potassium hexacyanoferrate(II). Different sensitivity and selectivity were obtained with the electrodes. Large responses were for example found for the amino acid and the carbohydrate using the copper, nickel and silver electrode. Some of the electrodes were employed in multicomponent solutions, i.e., liquid washing detergents from different suppliers together with differential pulse voltammetry. Responses from the electrodes in combination with PCA showed that they separated the detergents to different extents. This was further used when information from the sensors was merged together for successful discrimination of the detergents. It was found that two detergents close to each other in the score plot were from the same supplier. Furthermore. scanning electron microscopy (SEM) was used to monitor surface changes at the nonnoble electrodes (copper, nickel, and silver).
7.	Holmin, Susanne, et al. (författare) Multivariate optimisation of electrochemically pre-treated electrodes used in a voltammetric electronic tongue 2004 Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 519:1, s. 39-46 Tidskriftsartikel (refereegranskat)abstract The use of experimental design as a tool to optimise electrochemically cleaned electrodes applied in a voltammetric electronic tongue is described. A simple and quick activation of electrode surfaces is essential for this type of device, especially for on-line applications in industrial processes. The electronic tongue consisted of four metal electrodes, e.g. Au, Ir, Pt, and Rh in a three-electrode configuration. Current was measured as a function of large potential pulses of decreasing amplitude applied to each electrode. Preliminary results showed that electrochemical cleaning activated the electrode surfaces to similar extent as polishing. Settings of potential and time for each electrode was determined with experimental design in a solution containing 1.0 mM K 4[Fe(CN)6] in 0.1 M phosphate buffer (pH 6.8). Electrode surfaces were deactivated in-between measurements in a complex liquid, like tea. Optimal settings for potential and time in the electrochemical cleaning procedure at each electrode were chosen at recoveries of 100% (compared to polished electrodes). The recoveries were larger than 100% when too large potentials and times were applied. This could be explained by the fact that the electrode areas increased and therefore also the current responses. Principal component analysis (PCA) was used to investigate the stability of the electrode settings at 100% recoveries. No obvious trends of drift in the signals were found. © 2004 Elsevier B.V. All rights reserved.
8.	Ivarsson, Patrik, et al. (författare) A voltammetric electronic tongue 2005 Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 30, s. I258-i259 Tidskriftsartikel (refereegranskat)
9.	Ivarsson, Patrik, et al. (författare) Comparison of a voltammetric electronic tongue and a lipid membrane taste sensor 2001 Ingår i: Analytica Chimica Acta. - 0003-2670 .- 1873-4324. ; 449:1-2, s. 59-68 Tidskriftsartikel (refereegranskat)abstract An electronic tongue based on voltammetry and a multichannel lipid membrane taste sensor based on potentiometry are compared using two aqueous examples: detergents and teas. The electronic tongue consists of four electrodes of different metals, a reference electrode and a counter electrode. The measurement principle is based on pulse voltammetry in which current is measured during the change of the amplitude of the applied potential. The taste sensor is based on eight different lipid/polymer membranes. The voltage difference between the electrodes and an Ag/AgCl reference electrode is measured when the current is close to zero. The responses from the two sensors systems are treated separately with multivariate data analysis based on principal component analysis and then merged to examine if further information could be extracted. It is shown that although the two sensor systems are about equal in separation ability in the two cases, extra information can be gained by combination of the two sensor systems. © 2001 Elsevier Science B.V. All rights reserved.
10.	Ivarsson, Patrik, et al. (författare) Discrimination of tea by means of a voltammetric electronic tongue and different applied waveforms 2001 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract A new sensor technology, an electronic tongue based on voltammetry has been developed at Linköping University. Three different metallic working electrodes are used in combination with a set of voltage "pulses", a waveform, to separate different samples. In this paper, three different waveforms are investigated. This is done through a study with nine different teas. Multivariate data analysis ((MVDA), principal component analysis (PCA)) is used to evaluate the data (the recorded current responses). The waveforms are large amplitude pulse voltammetry (LAPV), small amplitude pulse voltammetry (SAPV), and staircase voltammetry. Each method discriminated between the tea samples to some extent, but differently from each other. Best discrimination is achieved when the combination LAPV and staircase are merged together. When SAPV is included in the combination a worse separation is observed. It is clearly the case that more waveforms do not automatically lead to more information. © 2001 Elsevier Science B.V.
11.	Ivarsson, Patrik, et al. (författare) Supervision of rinses in a washing machine by a voltammetric electronic tongue 2005 Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 108:01-Feb, s. 851-857 Tidskriftsartikel (refereegranskat)abstract A study that investigates if it is possible to discriminate between the different rinses in a household washing machine with a voltammetric electronic tongue is concluded. The voltammetric electronic tongue applies a potential pulse train over two electrodes and measures the produced current. Multivariate data analysis is used to treat the data. In this paper, a simplified electronic tongue, with only 5% of the original current responses, is used. The rinses from 20 machine wash runs with four different prerequisites are investigated. Principal component analysis (PCA) and Soft-independent modelling of class analogy (SIMCA) are used in order to classify the rinses. In PCA, only one of the rinses is classified erroneous, and in SIMCA none of the rinses are classified only to the wrong class, although 38% of the rinses are classitied to more than one class. (c) 2005 Elsevier B.V. All rights reserved.
12.	Jõgi, Nils Oskar, et al. (författare) Device comparison study to measure nasal nitric oxide in relation to primary ciliary dyskinesia 2024 Ingår i: Journal of Breath Research. - : Institute of Physics Publishing (IOPP). - 1752-7155 .- 1752-7163. ; 18:1 Tidskriftsartikel (refereegranskat)abstract Primary ciliary dyskinesia (PCD) is a genetic respiratory disease characterized by chronic cough, recurrent respiratory infections, and rhinosinusitis. The measurement of nasal nitric oxide (nNO) against resistance has been suggested as a sensitive screening method. However, current recommendations argue for the use of expensive, chemiluminescence devices to measure nNO. This study aimed to compare nNO measurement using three different devices in distinguishing PCD patients from healthy controls and cystic fibrosis (CF) patients and to evaluate their diagnostic precision. The study included 16 controls, 16 PCD patients, and 12 CF patients matched for age and sex. nNO measurements were performed using a chemiluminescence device (Eco Medics CLD 88sp), and two devices based on electrochemical sensors (Medisoft FeNO+ and NIOX Vero) following standardized guidelines. Correlation estimation, Bland-Altman, ROC curve, and one-way ANOVA were used to assess device differences and diagnostic performance. Significantly lower nNO output values were observed in PCD and CF patients compared to controls during exhalation against resistance. The correlation analysis showed high agreement among the three devices. ROC curve analysis demonstrated 100% sensitivity and specificity at different cut-off values for all devices in distinguishing PCD patients from controls (optimal cut-offs: EcoMedics 73, Medisoft 92 and NIOX 87 (nl min-1)). Higher nNO output values were obtained with the Medisoft and NIOX devices as compared to the EcoMedics device, with a bias of-19 nl min-1(95% CI: -73-35) and -21 nl min-1(-73-31) accordingly. These findings indicate that all three tested devices can potentially serve as diagnostic tools for PCD if device specific cut-off values are used. This last-mentioned aspect warrants further studies and consideration in defining optimal cut-offs for individual device.
13.	Johansson, E., et al. (författare) Chlorination and biodegradation of lignin 2000 Ingår i: Soil Biology and Biochemistry. - 0038-0717 .- 1879-3428. ; 32:7, s. 1029-1032 Tidskriftsartikel (refereegranskat)abstract Recent research has shown that large amounts of high-molecular weight organic chlorine of unknown origin are present in the terrestrial environment. There are indications that an underlying process may be microorganisms which produce reactive chlorine that chemically degrades organic matter and facilitates degradation of recalcitrant organic matter on one hand, and on the other hand causes a formation of organic chlorine. Our aim was to test one part of this hypothesis by investigating whether reactive chlorine facilitates microbial degradation of lignin. Different concentrations of chlorine dioxide were added to the autoclaved lignin suspension. Mycelium of the white-rot fungus P. chrysosporium was used to inoculate flasks with the lignin solutions. The evolution of CO2 was followed during 8 d of continuous measurement. At the end of the experiment the solutions were analyzed for organic chlorine. The amount of CO2 evolved was variable, but the results were repeatedable, addition of chlorine dioxide to the lignin solutions caused an increase in the mineralization by P. chrysosporium that increased with increasing additions of chlorine dioxide. This suggests that exposure of lignin to reactive chlorine enhance its biodegradability. The most likely cause of the observed effect is that the addition of chlorine dioxide initiated a fragmentation and oxidation of the lignin, thus rendering a more easily degraded substrate. However, the results may also be interpreted as if an additional cause to the observed effect is that the chlorination in itself somehow enhanced degradation. The amount of organically-bound chlorine decreased during the incubation, and the decrease was more pronounced with the chlorination of lignin, whereas no change at all was observable in the control batches. This makes it tempting to suggest that P. chrysosporium rather than having an enzyme system just capable of handling the chlorinated compounds, actually has a system that preferentially degrades such compounds. (C) 2000 Elsevier Science Ltd.
14.	Johnson, Håkan, 1966-, et al. (författare) Predicting microbial growth in pulp using an electronic tongue 2003 Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 18:2, s. 134-140 Tidskriftsartikel (refereegranskat)abstract This paper describes how an electronic tongue based on pulsed voltammetry over noble metal electrodes can be used as an instrument to predict the amount of microorganisms in pulp during their growth cycle. The electronic tongue consists of a sensor body and a PC, which is used to control a potentiostat which applies the voltammetric large amplitude pulsed voltammetry (LAPV)-waveform across the sensor electrodes, and to collect the data of the resulting current. The sensor body is constructed of four noble metal electrodes, a stainless steel electrode as counterelectrode, and an Ag/AgCl reference electrode. This arrangement works as a standard three-electrode voltammetry system. Principal component analysis (PCA) and partial least squares (PLS) multivariate prediction methods are used to extract information from the data and to aid interpretation. It is shown that PLS-models of the voltammetric signals from this sensor array predicts the reference methods, viable count using Petrifilm(TM) aerobic total counts, with good accuracy (root mean square error of prediction (RMSEP) 9% of maximum value or 20% in a lower region corresponding to 500-1000 colony forming units) and adenosine triphosphate (ATP)-measurements with lower accuracy (10% of maximum value or 55% in a lower region). Since the precision of this method of detection is on a level with the viable count method, this method can be considered superior where short response times or the possibility of on-line measurement are of value.
15.	Krantz, Ann-Margret, 1944-, et al. (författare) Riskfactors for pressure sore among newly operated patients, a prospective study 1999 Ingår i: 8th Annual Meeting of th European Tissue Repair Society,1999. Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
16.	Krantz, Christina, et al. (författare) Cross-sectional study on exhaled nitric oxide in relation to upper airway inflammatory disorders with regard to asthma and perennial sensitization 2022 Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 52:2, s. 297-311 Tidskriftsartikel (refereegranskat)abstract Background Fractional exhaled nitric oxide (FeNO) is a well-known marker of type-2 inflammation. FeNO is elevated in asthma and allergic rhinitis, with IgE sensitization as a major determinant. Objective We aimed to see whether there was an independent association between upper airway inflammatory disorders (UAID) and FeNO, after adjustment for asthma and sensitization, in a multi-centre population-based study. Methods A total of 741 subjects with current asthma and 4155 non-asthmatic subjects participating in the second follow-up of the European Community Respiratory Health Survey (ECRHS III) underwent FeNO measurements. Sensitization status was based on measurement of IgE against airborne allergens; information on asthma, UAID and medication was collected through interview-led questionnaires. Independent associations between UAID and FeNO were assessed in adjusted multivariate regression models and test for interaction with perennial sensitization and asthma on the relation between UAID and FeNO were made. Results UAID were associated with higher FeNO after adjusting for perennial sensitization, asthma and other confounders: with 4.4 (0.9-7.9) % higher FeNO in relation to current rhinitis and 4.8 (0.7-9.2) % higher FeNO in relation to rhinoconjunctivitis. A significant interaction with perennial sensitization was found in the relationship between current rhinitis and FeNO (p = .03) and between rhinoconjunctivitis and FeNO (p = .03). After stratification by asthma and perennial sensitization, the association between current rhinitis and FeNO remained in non-asthmatic subjects with perennial sensitization, with 12.1 (0.2-25.5) % higher FeNO in subjects with current rhinitis than in those without. Conclusions & Clinical Relevance Current rhinitis and rhinoconjunctivitis was associated with higher FeNO, with an interaction with perennial sensitization. This further highlights the concept of united airway disease, with correlations between symptoms and inflammation in the upper and lower airways and that sensitization needs to be accounted for in the relation between FeNO and rhinitis.
17.	Krantz, Christina, et al. (författare) Exhaled and nasal nitric oxide in relation to lung function, blood cell counts and disease characteristics in cystic fibrosis 2017 Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 11:2 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Patients with cystic fibrosis (CF) have similar or lower exhaled nitric oxide (FeNO) and lower nasal nitric oxide (nNO) levels than controls. There are divergent results on alveolar NO (CalvNO) concentrations in relation to CF. There are inconsistent results on correlation between different nitric oxide parameters and lung function and inflammation in CF.AIM: To compare FeNO, CalvNO and nNO levels between subjects with CF, asthma and healthy controls and to study whether these parameters are related to lung function, blood cell counts or clinical characteristics in CF patients.MATERIAL AND METHODS: Measurements of FeNO at multiple exhalation flow rates, nNO and spirometry were done in 38 patients (18 adults) with CF. Blood cell counts and CF clinical characteristics were recorded. Thirty-eight healthy controls and 38 asthma patients, gender- and age-matched, were included as reference groups.RESULTS: FeNO levels were lower in CF patients (7.2 [4.7-11.2] ppb) than in healthy controls (11.4 [8.3-14.6] ppb) and asthma patients (14.7 [8.7-24.7] ppb) (both p < 0.005). These differences were consistent in adults. No difference in CalvNO was seen between the groups. nNO levels in CF patients (319 [193-447] ppb) were lower than in healthy controls (797 [664-984] ppb) and asthma patients (780 [619-961] ppb) (both p < 0.001). FeNO positively related to FEV1 (rho = 0.51, p = 0.001) in CF patients and this was consistent in both adults and children. A negative correlation was found between FeNO and blood neutrophil counts (rho = -0.37, p = 0.03) in CF patients.CONCLUSION: CF patients have lower FeNO and nNO and similar CalvNO levels as healthy controls and asthma patients. Lower FeNO related to lower lung function in both adults and children with CF. Furthermore, in CF, lower FeNO also related to higher blood neutrophil counts.
18.	Krantz, Christina, et al. (författare) Longitudinal changes in exhaled and nasal nitric oxide in children and young adults with asthma 2018 Ingår i: European Respiratory Journal. - : EUROPEAN RESPIRATORY SOC JOURNALS LTD. - 0903-1936 .- 1399-3003. ; 52 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
19.	Krantz, Christina, et al. (författare) Nasal nitric oxide in relation to asthma characteristics in a longitudinal asthma cohort study 2021 Ingår i: Nitric oxide. - : Elsevier. - 1089-8603 .- 1089-8611. ; 106, s. 1-8 Tidskriftsartikel (refereegranskat)abstract OBJECTIVE: Cross-sectional studies report relations between low nasal nitric oxide (nNO) and poor asthma control and between low nNO and chronic rhinosinusitis (CRS). In our cohort study, we studied if changes in nNO related to changes in asthma control, symptoms of CRS, or asthma or rhinitis medication.METHODS: A total of 196 subjects with predominantly mild to moderate asthma, aged 10-35 years, performed nNO measurements at both baseline and follow-up after a median of 43 (range 23-65) months. Asthma control, CRS symptoms, and medication, were questionnaire-assessed at both timepoints. IgE sensitisation against aeroallergens was quantified at baseline.RESULTS: There was an increase in nNO between baseline and follow-up (764 ± 269 ppb vs. 855 ± 288 ppb, p < 0.001). When adjusted for covariates, a larger increase in nNO was found in subjects sensitised to perennial aeroallergens than those not sensitised (92 (16-167) ppb), as well as in subjects with daily use of inhaled corticosteroids (ICS) at baseline but not at follow-up than those on ICS daily at both timepoints (146 (51-242) ppb). In the same model, subjects using nasal steroids daily at both timepoints had decreased nNO compared with those without such treatment at both timepoints (-185 (-321-(-48)) ppb). No relations between changes in nNO levels and changes in asthma control or symptoms of CRS were found.CONCLUSION: Longitudinal changes in nNO were not related to changes in asthma control, but were related to changes in asthma or rhinitis medication.
20.	Krantz, Christina, et al. (författare) Nasal nitric oxide is associated with exhaled NO, bronchial responsiveness and poor asthma control 2014 Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 8:2, s. 026002- Tidskriftsartikel (refereegranskat)abstract The fraction of exhaled nitric oxide (FeNO) is an established marker of airway inflammation in asthma. Nasal nitric oxide (nNO) has initially been regarded as a promising marker of inflammation of nasal mucosa. However, due to its dual origins, paranasal sinuses and nasal mucosa, the clinical use of nNO is controversial. There is an inflammatory link between inflammation in the upper and lower airways within the united airways' paradigm, but the study of the clinical value of nNO in asthma has been limited. The objective of this study is to analyse nNO in asthmatics and its relationship to FeNO, bronchial hyperresponsiveness, allergic sensitization and asthma control. A total of 371 children and young adults from an asthma cohort were included in this study, which performed measurements of nNO (through aspiration at 5 mL s(-1)), FeNO, bronchial responsiveness to methacholine, blood eosinophil count (B-Eos) and IgE sensitization. The asthma control test (ACT) and a questionnaire regarding medical treatment, symptoms of asthma, rhinitis and chronic rhinosinusitis were completed by all subjects. An association was found between higher nNO levels and increased bronchial responsiveness (p < 0.001), FeNO (p < 0.001) and B-Eos (p = 0.002). Sensitization to furry animals related to higher levels of nNO (p < 0.001). Subjects with poorly controlled asthma (ACT < 15) had lower levels of nNO than subjects with a higher ACT score (619 +/- 278 ppb, versus 807 +/- 274 ppb, p = 0.002). Loss of smell showed the strongest association with lower nNO levels among the upper airway symptoms recorded. In patients with asthma, nNO was positively correlated with exhaled NO, bronchial responsiveness and asthma control. This study suggests clinical utility of nNO in subjects with asthma, but in order to get better understanding of the nNO determinants, simultaneous mapping of upper airway comorbidities by clinical examination is appropriate.
21.	Krantz, Christina (författare) Nitric oxide within the concept of united airway disease : Exhaled and nasal nitric oxide in cystic fibrosis, asthma and upper airway inflammatory diseases 2021 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Background: Within the concept of united airway disease, it is postulated that inflammatory disorders in the upper and lower airways are interrelated and influence each other. Fractional exhaled nitric oxide (FeNO) is an established biomarker of type-2 inflammation in the lower airways and is elevated in patients with asthma. However, the relation between nasal nitric oxide (nNO) and upper airway inflammation is less clear. Although cystic fibrosis (CF) is associated with increased airway inflammation, nitric oxide is not elevated in patients with CF.Aims: To study nNO and FeNO as biomarkers of type-2 inflammation in the upper and lower airways, respectively, in relation to symptoms, disease control and treatment of both upper and lower airway diseases, and in relation to systemic inflammation.Methods: This thesis is based on the MIDAS cohort of children and young adults with asthma (n=411) with a follow-up after 2-5 years (n=258), as well as one cohort of children and adults with CF (n=38) and one multicentre population-based cohort of middle-aged adults (n=5,824). Cross-sectional (Paper I-IV) and longitudinal (Paper III) analyses were performed. The main outcomes were nNO (Paper I-III) and FeNO (Paper II and IV) and their relations to IgE sensitisation, upper and lower airway symptoms and treatment, and systemic inflammation.Results: In subjects with asthma, nNO was associated with FeNO and increased bronchial responsiveness and nNO was higher in subjects with perennial sensitisation. In non-asthmatic middle-aged subjects with perennial sensitisation, rhinitis and rhinoconjunctivitis were associated with higher FeNO. There was also a positive interaction with perennial sensitisation for the relation between upper airway inflammatory disorders and FeNO. Treatment with nasal or inhaled corticosteroids was associated with lower nNO levels in subjects with asthma. In middle-aged subjects with asthma and perennial sensitisation, use of nasal corticosteroids related to lower FeNO, whereas use of inhaled corticosteroids related to higher FeNO levels. Patients with CF had lower levels of nNO and FeNO than controls. Moreover, lower FeNO levels were associated with lower lung function and higher blood neutrophil counts in CF.Conclusion: Within the concept of united airway disease, nNO is related to lower airway inflammation, responsiveness and treatment, and FeNO is related to upper airway inflammatory disorders, with a significant interaction with perennial sensitisation. In CF, lower FeNO is related to more severe disease with lower lung function and more systemic inflammation.
22.	Krantz-Rülcher, Christina, et al. (författare) Electronic tongues for environmental monitoring based on sensor arrays and pattern recognition : A review 2001 Ingår i: Analytica Chimica Acta. - 0003-2670 .- 1873-4324. ; 426:2, s. 217-226 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract The use of sensor arrays and pattern recognition applied to the obtained signal patterns for environmental monitoring are discussed in some detail. Different types of electronic tongues are described and evaluated for monitoring purposes. More specifically the performance of multielectrode arrays used for voltammetric analysis of aqueous samples is described. It is, e.g. shown how such an 'electronic tongue' can be used to monitor the quality of water in a production plant for drinking water. It is pointed out that the concepts of 'electronic noses' and 'electronic tongues' often predict a quality of a sample rather than giving exact information about concentrations of individual species. (C) 2001 Elsevier Science B.V.
23.	Lifvergren, Thomas, et al. (författare) Fungal responses to mercury Annan publikation (övrigt vetenskapligt/konstnärligt)
24.	Lindblad, Anders, et al. (författare) Clinical, economic, and societal burden of cystic fibrosis and the impact of the CFTR modulator, lumacaftor/ivacaftor : an assessment using linked registry data in Sweden 2024 Ingår i: Journal of Medical Economics. - : Taylor & Francis. - 1369-6998 .- 1941-837X. ; 27:1, s. 897-906 Tidskriftsartikel (refereegranskat)abstract AimsWe aimed to describe the clinical, economic, and societal burdens of cystic fibrosis (CF) and impact of CF transmembrane conductance regulator modulator (CFTRm) treatment on people with CF, caregivers, and healthcare systems.Material and methodsThis retrospective study used linked real-world data from Swedish national population-based registries and the Swedish CF Quality Registry to assess clinical, economic, and societal burden and CFTR impact in CF. Records from people with CF and a ten-fold control population without CF matched by sex, birth year, and location were compared during 2019. Outcomes for a subset aged >6 years initiating lumacaftor/ivacaftor (LUM/IVA) in 2018 were compared 12 months pre- and post-treatment initiation.ResultsPeople with CF (n = 743) had >10 times more inpatient and outpatient specialist visits annually vs controls (n = 7406). Those aged >18 had an additional 77·7 (95% CI: 70·3, 85·1) days of work absence, at a societal cost of €11,563 (95% CI: 10,463, 12,662), while caregivers of those aged <18 missed an additional 6.1 (5.0, 7.2) workdays. With LUM/IVA treatment, people with CF (n = 100) had significantly increased lung function (mean change in ppFEV1 [3·8 points; 95% CI: 1·1, 6·6]), on average 0·5 (95% CI: −0·8, −0·2) fewer pulmonary exacerbations and 45·2 (95% CI: 13·3, 77·2) fewer days of antibiotics. Days of work lost by caregivers of people with CF aged <18 decreased by 5·4 days (95% CI: 2·9, 7·9).ConclusionCF is associated with a high clinical economic and societal burden in Sweden. Improvements in clinical status observed in people with CF treated with LUM/IVA were reflected in reduced caregiver and societal burden.
25.	Lindgren, Margareta, 1951-, et al. (författare) A risk assessment scale for the prediction of pressure sore development : reliability and validity 2002 Ingår i: Journal of Advanced Nursing. - : Wiley. - 0309-2402 .- 1365-2648. ; 38:2, s. 190-199 Tidskriftsartikel (refereegranskat)abstract Background. The ability to assess the risk of a patient developing pressure sores is a major issue in pressure sore prevention. Risk assessment scales should be valid, reliable and easy to use in clinical practice.Aim. To develop further a risk assessment scale, for predicting pressure sore development and, in addition, to present the validity and reliability of this scale.Methods. The risk assessment pressure sore (RAPS) scale, includes 12 variables, five from the re-modified Norton scale, three from the Braden scale and three from other research results. Five hundred and thirty patients without pressure sores on admission were included in the study and assessed over a maximum period of 12 weeks. Internal consistency was examined by item analysis and equivalence by interrater reliability. To estimate equivalence, 10 pairs of nurses assessed a total of 116 patients. The underlying dimensions of the scale were examined by factor analysis. The predictive validity was examined by determination of sensitivity, specificity and predictive value.Results. Two variables were excluded as a result of low item–item and item–total correlations. The average percentage of agreement and the intraclass correlation between raters were 70% and 0·83, respectively. The factor analysis gave three factors, with a total variance explained of 65·1%. Sensitivity, specificity and predictive value were high among patients at medical and infection wards.Conclusions. The RAPS scale is a reliable scale for predicting pressure sore development. The validity is especially good for patients undergoing treatment in medical wards and wards for infectious diseases. This indicates that the RAPS scale may be useful in clinical practice for these groups of patients. For patients undergoing surgical treatment, further analysis will be performed.
26.	Lindgren, Margareta, 1951-, et al. (författare) Pressure ulcer risk factors in patients undergoing surgery 2005 Ingår i: Journal of Advanced Nursing. - : Wiley. - 0309-2402 .- 1365-2648. ; 50:6, s. 605-612 Tidskriftsartikel (refereegranskat)abstract Aim. This paper reports a study to identify risk factors associated with pressure ulcer development among a mixed group of adult patients undergoing surgery. Background. Few studies have been carried out with patients undergoing surgery to assess the risk of pressure ulcer development, and so there is a little knowledge of the risk factors for this group. However, studies among non-surgical patients have shown that nutritional predictors such as low serum albumin level and low body mass index (BMI) are of great importance. An additional predictive factor may be low blood pressure. It is important to study these predictors further among patients undergoing surgery, using techniques such as multiple regression techniques, designed to identify the most important predictors for pressure ulcer development. Methods. A prospective comparative study was carried out in 1996-1998 with 286 adult patients undergoing surgical treatment. The data were collected from patient records by Registered Nurses preoperatively, for seven days postoperatively and thereafter once a week for up to 12 weeks. Perioperative data were also collected. The Risk Assessment Pressure Sore Scale was used, and data were collected on general physical condition, activity, mobility, moisture, food intake, fluid intake, sensory perception, friction and shear, body temperature and serum albumin. Results. Forty-one (14.3%) patients developed pressure ulcers during the observation period. The most common type was non-blanchable erythema. Those who developed pressure ulcers were significantly older, weighed less, and had a lower BMI and serum albumin. More women than men developed pressure ulcers. Risk factors identified in multiple stepwise regression analyses were female gender, American Society of Anaesthesiologists (ASA) status or New York Heart Association (NYHA) status and food-intake. Conclusion. Special attention, with regard to risk of pressure ulcer development, should be paid to patients undergoing surgery who have low ASA or NYHA scores, low food intake and/or are women. © 2005 Blackwell Publishing Ltd.
27.	Lindgren, Margareta, 1951-, et al. (författare) Risk factors associated with pressure sore development among hospitalized patients 2004 Ingår i: 12th Biennial Conference of the Workgroup of European Nurse Researchers,2004. Konferensbidrag (övrigt vetenskapligt/konstnärligt)
28.	Medbo, Jakob, et al. (författare) Telemedicine and home spirometry in cystic fibrosis: A prospective multicenter study 2024 Ingår i: PEDIATRIC PULMONOLOGY. - 8755-6863 .- 1099-0496. Tidskriftsartikel (refereegranskat)abstract Objectives: Telehealth and home spirometry feasibility for children has been established, but their impact on cystic fibrosis (CF) disease progression remains unassessed. We aimed to evaluate the effects of telehealth and home spirometry on CF disease progression and care. Methods: Children with CF aged 5-17 years from all Swedish CF centers were provided with home spirometers. A minimum of two in-person visits were replaced with telemedicine visits and participants were instructed to conduct home spirometry before visits. Linear mixed-effects models were used to compare annual CF disease trajectories during the intervention period and prepandemic period (1 January 2019 to 28 February 2020). Participants and caregivers completed study questionnaires. Results: A total of 59 individuals completed the study over a mean (SD) period of 6.8 (1.4) months, made 3.1 (1.0) physical visits and 2.2 (0.6) telehealth visits per patient year during the study period. The mean difference (95% CI) between the intervention and prepandemic period progression rate for FEV1%, lung clearance index and BMI were -0.4 (-1.3 to 0.5, p = 0.39), 0.11 (-0.07 to 0.28, p = 0.25) and -0.02 (-0.13 to 0.08, p = 0.70), respectively. There were no major shifts in the incidence of airway pathogens, sputum cultures, or antibiotics use between the periods (p > 0.05). The intervention did not increase stress. Almost all participants and caregivers expressed a desire to continue with home spirometry and telemedicine. Conclusion: Combining telehealth and physical visits with access to home spirometry demonstrated comparable effectiveness as exclusively in-person care with enhanced flexibility and personalization of CF care.
29.	Söderström, Charlotte, 1973-, et al. (författare) Differentiation of four Aspergillus species and one Zygosaccharomyces with two electronic tongues based on different measurement techniques 2005 Ingår i: Journal of Biotechnology. - : Elsevier BV. - 0168-1656 .- 1873-4863. ; 119:3, s. 300-308 Tidskriftsartikel (refereegranskat)abstract Two electronic tongues based on different measurement techniques were applied to the discrimination of four molds and one yeast. Chosen microorganisms were different species of Aspergillus and yeast specie Zygosaccharomyces bailii, which are known as food contaminants. The electronic tongue developed in Linköping University was based on voltammetry. Four working electrodes made of noble metals were used in a standard three-electrode configuration in this case. The St. Petersburg electronic tongue consisted of 27 potentiometric chemical sensors with enhanced cross-sensitivity. Sensors with chalcogenide glass and plasticized PVC membranes were used. Two sets of samples were measured using both electronic tongues. Firstly, broths were measured in which either one of the molds or the yeast grew until late logarithmic phase or border of the stationary phase. Broths inoculated by either one of molds or the yeast was measured at five different times during microorganism growth. Data were evaluated using principal component analysis (PCA), partial least square regression (PLS) and linear discriminant analysis (LDA). It was found that both measurement techniques could differentiate between fungi species. Merged data from both electronic tongues improved differentiation of the samples in selected cases. © 2005 Elsevier B.V. All rights reserved.
30.	Söderström, Charlotte, et al. (författare) Recognition of six microbial species with an electronic tongue 2003 Ingår i: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 89:3, s. 248-255 Tidskriftsartikel (refereegranskat)abstract An electronic tongue based on pulsed voltammetry over an array of electrodes with different selectivity and sensitivity patterns was used to recognize six different microorganisms: one yeast, two bacteria, and three molds. Measurements were performed during the whole growth period, from the lag phase to the stationary phase. The electrode array was dipped into the malt extract growth medium and voltage was applied over the electrodes in pulses of different amplitude and the resulting current data was sampled and collected in a matrix. Evaluation of the electronic tongue data was made with principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). PCA was performed on data from the lag, the logarithmic, and also the stationary growth phase. In the lag growth phase no recognition of species was visible in the PCA score plots. After further growth however all the included microbial species could be recognized from each other. The ability to predict membership of new replicates of the species to the right classes was verified with SIMCA. © 2003 Elsevier Science B.V. All rights reserved.
31.	Söderström, Charlotte, 1973-, et al. (författare) Use of an electronic tongue and HPLC with electrochemical detection to differentiate molds in culture media 2005 Ingår i: International Journal of Food Microbiology. - 0168-1605 .- 1879-3460. ; 97:3, s. 247-257 Tidskriftsartikel (refereegranskat)abstract A study was conducted to further evaluate an electronic tongue, using high-performance liquid chromatography (HPLC) with electrochemical (EC) and UV detection as a reference method. The electronic tongue consisted of four working electrodes made of different metals and arranged in a standard three-electrode configuration. Pulses of voltage were applied to the metals, and the current responses were sampled and collected in a data matrix. The objectives of the present investigation were to examine the ability of the electronic tongue to distinguish between two mold species growing in three different media, and to obtain support for the hypothesis that the device actually discriminates between different redox-active metabolites produced by the molds. Peak areas in EC and UV HPLC chromatograms were collected in a data matrix. The electronic tongue data and the EC and UV data were then subjected to principal component analysis (PCA). A number of peaks in the HPLC-EC chromatograms indicated that the growth media contained redox-active metabolites. Moreover, PCA of peak areas in EC chromatograms revealed differences between the distribution of redox-active metabolites produced by the two species and between the three culture media. The same pattern was apparent in a PCA score plot of electronic tongue data. The peaks in the UV and EC chromatograms differed, and these were also shown by the PCA score plots.
32.	Söderström, Charlotte, et al. (författare) Use of an electronic tongue to analyze mold growth in liquid media 2003 Ingår i: International Journal of Food Microbiology. - 0168-1605 .- 1879-3460. ; 83:3, s. 253-261 Tidskriftsartikel (refereegranskat)abstract The feasibility of employing an electronic tongue to measure the growth of mold in a liquid medium was studied. We used the electronic tongue developed at Linköping University, which is based on pulsed voltammetry and consists of an array of different metal electrodes. Instead of focusing on a single parameter, this device provides information about the condition or quality of a sample or process. Accordingly, the data obtained are complex, and multivariate methods such as principal component analysis (PCA) or projection to latent structures (PLS) are required to extract relevant information. A gas chromatographic technique was developed to measure ergosterol content in mold biomass and was subsequently used as a reference method to investigate the ability of the electronic tongue to measure the growth of mold in liquid media. The result shows that the electronic tongue can monitor mold growth in liquids. In PLS analysis, the electronic tongue signals correlate well with the amount of ergosterol in the mold biomass as well as the microbially induced changes in the pH of the medium. © 2002 Elsevier Science B.V. All rights reserved.
33.	Ulrich, Christian, 1976-, et al. (författare) Simultaneous estimation of soot and diesel contamination in engine oil using electrochemical impedance spectroscopy 2007 Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 127:2, s. 613-618 Tidskriftsartikel (refereegranskat)abstract In this paper, we explore the combination of electrochemical impedance spectroscopy and multivariate data analysis to simultaneously predict the concentrations of soot and diesel in engine oil. For this purpose, we use a well defined measurement set-up to minimize interference from ambient noise, and to obtain a large amount of data in a short period of time. An imperative requirement is that soot and diesel affect the impedance in different ways over the employed frequency range. It was, for example, found that diesel had a larger influence at lower frequencies. Using partial least squares modelling we show that it is possible to simultaneously predict the concentrations of both soot and diesel in engine oil. Since the temperature in an engine varies, the influence of the oil temperature is investigated in a preliminary experiment. This study is a part of the development of an electrochemical on-board sensor for real-time monitoring of engine oil.
34.	Winquist, Fredrik, et al. (författare) A hybrid electronic tongue 2000 Ingår i: Analytica Chimica Acta. - 0003-2670 .- 1873-4324. ; 406:2, s. 147-157 Tidskriftsartikel (refereegranskat)abstract A hybrid electronic tongue is described based on a combination of potentiometry, voltammetry and conductivity. It was used for classification of six different types of fermented milk. Using ion-selective electrodes, pH, carbon dioxide and chloride ion concentrations were measured. The voltammetric electronic tongue consisted of six working electrodes of different metals (gold, iridium, palladium, platinum, rhenium and rhodium) and an Ag/AgCl reference electrode. The measurement principle is based on pulse voltammetry in which current transients are measured due to the onset of voltage pulses at decreasing potentials. The data obtained from the measurements were treated by multivariate data processing based on principal components analysis and an artificial neural net. The hybrid tongue could separate all six samples. Also, the nature of the micro-organisms in the different fermentations was reflected in the principal component analysis. Copyright (C) 2000 Elsevier Science B.V.
35.	Winquist, Fredrik, et al. (författare) A miniaturized voltammetric electronic tongue 2008 Ingår i: Analytical Letters. - : Informa UK Limited. - 0003-2719 .- 1532-236X. ; 41:5, s. 917-924 Tidskriftsartikel (refereegranskat)abstract A miniaturized electronic tongue based on pulsed voltammetry has been developed. It was made by inserting three types of wires acting as working electrodes (gold, platinum, and rhodium, diameter 0.25 mm) into a platinum tube acting as a counter electrode (diameter 2 mm, length 4 mm). The arrangement was connected to a potentiostat controlled by a computer. Due to the small size of the miniaturized electronic tongue, and since no reference electrode is used, the setup is very simple and convenient. In order to characterize the analytical possibilities of the miniaturized electronic tongue, some initial experiments were performed. These include the determination of trace amounts of cadmium and lead (in the µM range) in 5 µL samples. Furthermore, the setup was placed under the real tongue of a volunteer to follow saliva composition during exercise. Copyright © Taylor & Francis Group, LLC.
36.	Winquist, Fredrik, et al. (författare) An electronic tongue in the dairy industry 2005 Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 111, s. 299-304 Tidskriftsartikel (refereegranskat)abstract The concept of electronic tongues or taste sensors has developed rapidly during recent years due to their large potential. They are based on electrochemical sensors combined with multivariate data analysis. Voltammetric electronic tongues have proven valuable in many applications. Due to their ruggedness and simplicity, they have been found especially suitable for on-line monitoring of industrial processes. A voltammetric electronic tongue, specially designed for use in the dairy industry is described. It consisted of four working electrodes (gold, platinum, rhodium and stainless steel), embedded in PEEK (TM). It was mounted in a housing of stainless steel, which was inserted in the process line for direct on-line measurements. The voltammetric electronic tongue was used to follow different sources of milk coming into the process and to monitor the cleaning process. (c) 2005 Elsevier B.V. All rights reserved.
37.	Winquist, Fredrik, et al. (författare) Electronic tongues 2004 Ingår i: MRS bulletin. - 0883-7694 .- 1938-1425. ; 29:10, s. 726-731 Tidskriftsartikel (refereegranskat)abstract The use of multivariate data analysis combined with sensors with partially overlapping selectivities has become a very powerful tool in measurement technology. These systems are often referred to as artificial senses, because they function in a way similar to the human senses. One such system is the electronic nose. This article focuses on similar concepts as the electronic nose, but for use in aqueous solutions. Because these systems are related to the human sense of taste in the same way the electronic nose is related to olfaction, they have been termed taste sensors, or "electronic tongues." Various measurement principles that can be used in electronic tongues are described and discussed in this article, These include electrochemical techniques such as potentiometry, voltammetry, and conductometry. Also, optical techniques based on light absorption at specific wavelengths or the use of surface plasmon resonance are described. Mass-sensitive devices based on piezoelectric crystals have also been used and are described here. A special emphasis is given to the voltammetric electronic tongue.
38.	Winquist, Fredrik, et al. (författare) Flow injection analysis applied to a voltammetric electronic tongue 2002 Ingår i: Analytica Chimica Acta. - 0003-2670 .- 1873-4324. ; 471:2, s. 159-172 Tidskriftsartikel (refereegranskat)abstract A measurement system, based on flow injection analysis (FIA) technique applied to a voltammetric electronic tongue is described. A reference solution was thus continuously pumped through a cell with a voltammetric electronic tongue, and test samples were injected into the flow stream. Responses were obtained by measuring the resulting pulse height. The FIA technique offered several advantages, since relative measurements are performed, the system is less influenced by sensor baseline drift, calibration samples and/or washing solutions can be injected within a measurement series, and the system is well adapted for automatization. The system was used to analyze standard solutions of H2O2, KCl, CuNO3, K4[Fe(CN)6], K3[Fe(CN)6] and NaCl, and results obtained were treated with multivariate data analysis. Principal component analysis performed showed that electrode drift could be considerably decreased, and the set-up was also used for classification of different apple juices. © 2002 Elsevier Science B.V. All rights reserved.
39.	Winquist, Fredrik, et al. (författare) Measurements of cadmium in soil extracts using multi-variate data analysis and electrochemical sensors 2009 Ingår i: PRECISION AGRICULTURE. - : Springer Science and Business Media LLC. - 1385-2256 .- 1573-1618. ; 10:3, s. 231-246 Tidskriftsartikel (refereegranskat)abstract There is a growing awareness of potential health risks due to exposure to heavy metals. One source of uptake is via agriculture, when heavy metals in the soil are taken up by the crop. The metal cadmium holds a special position, since it is considered to be a health risk, even at the low concentrations observed in our food supply, furthermore, it is ranked as eight on the top 20 hazardous substances list. Two measurement systems are described based on stripping voltammetry for analysis of cadmium. One is based on a three metal direct probe system (TMDPS) with three working electrodes (platinum, gold and rhodium), combined with a polishing unit, the other is an automatic flow through system, using one working electrode of gold, also equipped with a polishing unit. A number of different soils were extracted with an ammonium-lactate solution and analyzed with the systems, and the data obtained were subjected to multi-variate data analysis (MVDA). Using modeling based on partial least square (PLS), concentrations of cadmium in the soil extracts could be predicted for the TMDPS in the concentration area 0.5-10 mu g/l with a root mean square error of prediction (RMSEP) of 0.8 mu g/l and a relative predicted deviation (RPV) of 2.0. One sample could be analyzed in 4 min. It was also shown that by using different PLS models, the concentration of the elements copper, aluminum, lead and iron could be predicted. The possibilities of using the technique for field use were also evaluated by studies of mixtures of different soils in 0.1 M HNO3 solution, the time for an analysis was, however, rather large, around 20 min.

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