Jana Sádecká

Slovak University of Technology in Bratislava, Presburg, Bratislavský, Slovakia

Are you Jana Sádecká?

Claim your profile

Publications (34)64.97 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Brandy, a spirit drink produced from wine (grape), is rich in phenolic acids due to its maturation in wooden barrels. Phenolic acids play a significant role in defining the sensorial characteristics of wines and brandies, and therefore, it is very useful to determine them. Synchronous fluorescence spectra of mixtures containing phenolic acids (gallic, vanillic, syringic and ferulic) and scopoletin have been used for the determination of these compounds by partial least squares (PLS)2. Synchronous fluorescence spectra were collected by simultaneously scanning the excitation and emission monochromator in the excitation wavelength range 200–500 nm, with constant wavelength difference 100 nm between them. The leave-one-out cross-validation method was used to select the optimum number of five PLS2 components (latent variables). The PLS2 model captured for 100 % of variance in the spectral block, and it accounted for 99.34 % of variance in the concentration block. The performance of the model was evaluated by means of root mean square error of cross-validation, root mean square error of prediction and coefficient of determination. The best model was used for the determination of the above-mentioned compounds in brandy samples at concentration levels 2–74 mg L−1 for phenolic acids and 0.06–0.43 mg L−1 for scopoletin. The PLS2 results were found to be in good agreement with those obtained by HPLC method.
    Food Analytical Methods 03/2014; · 1.97 Impact Factor
  • Diana Markechová, Pavel Májek, Jana Sádecká
    [Show abstract] [Hide abstract]
    ABSTRACT: The addition of mixed wine spirit to brandy is easy way to adulterate brandy. To avoid the misleading of the consumers, it is necessary to develop reliable method to detect adulteration of brandy. In this work excitation emission matrix fluorescence in combination with parallel factor analysis (PARAFAC) and partial least squares (PLS) regression was used to determine the content of mixed wine spirit in adulterated brandy samples. Excitation emission matrix fluorescence spectra were measured in the emission wavelength range of 485–580 nm and in the excitation wavelength range of 363–475 nm. The model created using PARAFAC–PLS was able to predict the mixed wine spirit level in adulterated brandy with the root mean square error of prediction (RMSEP) value of 1.9% and a square of the correlation (R2) between the reference contents and the predicted values of 0.995.
    Food Chemistry 01/2014; 159:193–199. · 3.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this work was to develop a multivariate method for the rapid determination of caffeine and Class IV caramel in cola-type soft drinks and of caffeine, Class III caramel and riboflavin in energy drinks using synchronous fluorescence spectra. The synchronous fluorescence spectra were recorded at constant wavelength difference 90 nm from 200 to 500 nm. Reference values of analyte concentrations by high performance liquid chromatography (HPLC) with fluorescence detection combined with the standard addition method were used to create the partial least squares (PLS) models. High coefficients of determination (>0.99) were obtained in 0.2–4.2, 0.25–5.25, 0.4–10.0 and 0.007–0.054 mg L−1 range for caffeine, Class III caramel, Class IV caramel and riboflavin, respectively. The PLS models were used to determine the concentration of analytes in different drink samples. The method provided comparable results with those found using the HPLC method.
    Food Chemistry 01/2014; 159:282–286. · 3.33 Impact Factor
  • Jana Sádecká, Jana Tóthová
    [Show abstract] [Hide abstract]
    ABSTRACT: Two spectrofluorimetric methods have been developed for the rapid determination of ellagic acid. The first method is based on the complex formation between ellagic acid and borax in methanol solution. The fluorescence of the complex is monitored at an emission wavelength of 456nm with excitation at 383nm. Linear calibration curve was obtained from 2.5×10(-8) to 7.5×10(-7)molL(-1) and the limit of determination was 4×10(-9)molL(-1). The second method is based on the complex formation between ellagic acid and boric acid in ethanol solution. The fluorescence of the complex is monitored at an emission wavelength of 447nm with excitation at 387nm. Linear calibration curve was obtained from 1.25×10(-7) to 1.00×10(-6)molL(-1) and the limit of determination was 7×10(-9)molL(-1). The methods were successfully applied for the determination of ellagic acid in brandy samples. The results were found to be in good agreement with those obtained by HPLC method.
    Food Chemistry 12/2012; 135(3):893-7. · 3.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper illustrates the composition of propolis samples obtained from two regions in the Slovak Republic and focuses on the determination of coumarins. The HPLC method with on-line spectrophotometric and fluorescent detection was used for the separation and the determination of coumarins from the subgroup of simple coumarins (esculin, daphnetin, fraxetin, umbelliferone, 4-methylumbelliferone, 4-hydroxycoumarin, scoparone, coumarin, herniarin) and cinnamyl alcohol. The results confirmed that the quantity of umbelliferone, 4-methylumbelliferone and scoparone in the propolis depends on the area of collection. The HPLC results were compared with those obtained by the spectrofluorimetric method developed for the determination of total coumarins (calculated as scoparone). For the quantification of total coumarins in propolis extracts we found 15% higher values of coumarin content by fluorescence spectrometry than by HPLC, which can be ascribed to the higher matrix effects on fluorescence spectra.
    Journal of Liquid Chromatography &amp Related Technologies 01/2012; · 0.57 Impact Factor
  • J. SADECKA, J. POLONSKY, H. SHINTANI
    [Show abstract] [Hide abstract]
    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 01/2010; 26(6).
  • Jana Sádecká, Jana Tóthová
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this research is to develop a fluorescence spectroscopic method for distinguishing between brandies aged in oak casks and non-aged caramel-colored mixed wine spirits, and subsequent determining of caramel in the latter. Owing to the low price of the mixed wine spirits, they are sometimes used for the counterfeiting brandies. For this reason, there is a need to establish a rapid method for estimation of drink quality to reassure consumer. The potential of synchronous fluorescence spectroscopy is demonstrated to differentiate caramel from oak wood extract, while the best discrimination is achieved using fluorescence spectra recorded at Δλ=40nm. For this offset value, oak wood extract shows band at 280nm and caramel shows band at 387nm. Based on this, caramel quantity in non-aged mixed wine spirits was calculated from fluorescence intensity at 387nm. The calibration curve was linear over the range from 5 to 56mg/L and the limit of determination was 5mg/L. The relative standard deviation was <4% (within-day) and it was <6% (between-day) at 10 or 30mg/L level.
    European Food Research and Technology 01/2010; 230(5):797-802. · 1.39 Impact Factor
  • Source
    Jana Sádecká, Jana Tóthová, Pavel Májek
    [Show abstract] [Hide abstract]
    ABSTRACT: a b s t r a c t This study demonstrates the use of front face fluorescence spectroscopy and multivariate data analysis for differentiating brandies from wine distillates. Owing to the low price of the wine distillates, they are sometimes used for the counterfeiting brandies. For this reason, there is a need for a rapid method for drink authentication to reassure consumers and protect regional designations. Total luminescence and synchronous scanning fluorescence spectra were recorded followed by a classification of samples using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Both PCA and HCA carried out on the emission spectra (360–650 nm) recorded at excitation wavelength 350 nm and syn-chronous fluorescence spectra (200–700 nm) collected at wavelength interval 90 nm provide very good differentiation between the two spirit classes. Less good classification was obtained using excitation spectra (225–425 nm) obtained at emission wavelength 440 nm. These results indicate that the front face fluorescence spectroscopy offers a promising approach for the authentication of brandies.
    Food Chemistry - FOOD CHEM. 01/2009; 117(3).
  • Source
    Jana Tóthová, Jana Sádecká, Pavel Májek
    [Show abstract] [Hide abstract]
    ABSTRACT: Tóthová J., Sádecká J., Májek P. (2007): Total luminescence spectroscopy for differentiating between brandies and wine distillates. Czech J. Food Sci., 27: 425–432. In this study, the differentiation was investigated between brandy and wine distillate samples by fluorescence spectros-copy in combination with multivariate analysis. The samples corresponding to eight brandies from three producers and sixteen wine distillates from five producers were acquired in the local supermarkets. Total luminescence spectra of diluted and undiluted samples were recorded. In order to extract reliable information from the data sets, two multi-variate analysis methods, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), were applied separately on the excitation and emission spectra. The best differentiation was achieved using the emission spectra (400–470 nm) recorded at the excitation wavelength of 340 nm, or the excitation spectra (240–380 nm) recorded at the emission wavelength of 450 nm. The similarity map defined by the PC1 and PC2 of the PCA performed on the excitation spectra accounted for 94.9% of the total variance (PC1 90.3%, PC2 4.6%) and allowed a good discrimination between the beverages. Although the PCA similarity map defined by the PC1 (84.2%) and PC2 (13.0%) performed on the emission spectra did not lead to a clear discrimination between the beverages, a general trend pointing out the brandies and wine distillates was observed on the map. HCA performed on the excitation spectra provided a better differentiation between the two classes, without any classification error, while HCA performed on the emission spectra allowed 95.8% correct classification.
    Czech J. Food Sci. 01/2009; 27:425-432.
  • Jana Sádecká, Pavel Májek, Jana Tóthová
    [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this work has been to assess the potential of capillary isotachophoretic organic acids profiling using multivariate statistical methods to classify brandy samples and wine distillate samples. The leading electrolyte was 10mmolL−1 hydrochloric acid including 0.1% methylhydroxylethylcellulose adjusted with β-alanine to pH 2.9. The terminating electrolyte was 5mmolL−1 acetic acid. Principal component analysis, cluster analysis, and linear discriminant analysis were used for the classification of beverages. The results show that for the 12 acids analysed, 98.57% of the total variance is extracted by the six principal components (PC). After performing backward linear discriminant analysis, a classification function was obtained containing four variables: formic (PC2-loadings: 0.989), lactic (PC1-loadings: 0.886), malic (PC1-loadings: 0.989) and oxalic (PC2-loadings: 0.777) acids, which provide 100.0% correct classification of brandies and wine distillates.
    Chromatographia 04/2008; 67:69-74. · 1.44 Impact Factor
  • Source
    Jana Tóthová, Ľudovít Žiak, Jana Sádecká
    [Show abstract] [Hide abstract]
    ABSTRACT: This study shows that brandy, whisky, slivovice, and juniper drink can be discriminated using differences in their synchronous fluorescence spectra. Although differentiation between samples was possible by visual inspection of the spectra, it was accomplished by multivariate data analysis method more easy. Comparison of the results obtained from multivariate data analysis indicated that better classification was obtained from synchronous fluorescence spectra than from the excitation/emission fluorescence spectra. Fluorescence spectroscopy offers a promising approach for the characterisation of distillates as neither sample preparation nor special qualification of the personnel are required, and data acquisition and analysis are relatively simple.
    01/2008; 1:265-275.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Selective SPE of derivates of p-hydroxybenzoic acid (pHBA) from plant extract of Melissa officinalis is presented using a molecularly imprinted polymer (MIP) made with protocatechuic acid (PA) as template molecule. MIP was prepared with acrylamide as functional monomer, ethylene glycol dimethacrylate as crosslinking monomer and ACN as porogen. MIP was evaluated towards six phenolic acids: PA, gallic acid, pHBA, vanillic acid (VA), gentisic acid (GeA) and syringic acid (SyrA), and then steps of molecularly imprinted SPE (MISPE) procedure were optimized. The best specific binding capacity of MIP was obtained for PA in ACN (34.7 microg/g of MIP). Other tested acids were also bound on MIP if they were dissolved in this solvent. ACN was chosen as solvent for sample application. M. officinalis was extracted into methanol/water (4:1, v/v), the extract was then evaporated to dryness and dissolved in ACN before application on MIP. Water and ACN were used as washing solvents and elution of benzoic acids was performed by means of a mixture methanol/acetic acid (9:1, v/v). pHBA, GA, PA and VA were extracted with recoveries of 56.3-82.1% using this MISPE method. GeA was not determined in plant extract.
    Journal of Separation Science 01/2006; 28(18):2468-76. · 2.59 Impact Factor
  • J Sádecká, J Netriová
    [Show abstract] [Hide abstract]
    ABSTRACT: A simple, sensitive and accurate spectrofluorimetric method was developed for the assay of fendiline in tablets. Validation of the method provided good results concerning linearity, precision and accuracy. The linearity range was found to be 0.1-0.8 mg/l. The fluorescence intensity was measured at 288 nm for fendiline tablet solutions. It was also found that the excipients in the commercial tablets did not interfere with the method.
    Pharmazie 11/2005; 60(10):792-3. · 0.96 Impact Factor
  • J Sádecká, M Cakrt
    [Show abstract] [Hide abstract]
    ABSTRACT: Non-ionic surfactant (Brij 35, Tween 20, Tween 80 and Tergitol NPX) modified capillary isotachophoresis was investigated for the separation of 2-arylpropionic acids (fenoprofen, flurbiprofen, ibuprofen, ketoprofen and naproxen) and benzoic acid and its derivatives (salicylic, acetylsalicylic and gallic acids). The relative step height (RSH) values of analytes were found to be dependent on the type and concentration of the surfactant. The strength of the affinity of the 2-arylpropionic acids to the non-ionic micelles was found to be as follows: flurbiprofen > fenoprofen > ibuprofen > naproxen > ketoprofen. In general, the RSH values of 2-arylpropionic acids increase with an increase in the concentration of surfactants. However, the RSHs of benzoic, salicylic and gallic acids are not considerably affected. Separation of all acids was obtained with the Tween 20 (1.5%, w/v) in the leading electrolyte 10 mmol L(-1) hydrochloric acid/L-histidine (pH 6.0). Changes in the fluorescence intensity of fenoprofen, flurbiprofen and naproxen were also investigated in micellar media (Tween 20, Tween 80 and Brij 35). The strength of the affinity of the 2-arylpropionic acids to the Tweens micelles was found to be as follows: flurbiprofen > fenoprofen > naproxen, which is consistent with the isotachophoretic results. On the contrary, the strength of the affinity to the Brij micelles was found to be as follows: fenoprofen > naproxen > flurbiprofen.
    Journal of Chromatography A 08/2005; 1084(1-2):152-9. · 4.61 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pantothenic acid (vitamin B5) has been quantified in non-fortified and fortified milk-based samples and fortified cornflakes samples by column-coupling capillary isotachophoresis. The leading electrolyte was 10 mmol/l hydrochloric acid including 0.1% polyvinylpyrrolidone adjusted with histidine to pH 6.0. The terminating electrolyte was 5 mmol/l 4-morpholineethanesulfonic acid adjusted with Tris(hydroxymethyl)aminomethane to pH 6.2. The driving current was 350 &#119A in the preseparation capillary. The driving current was initially 50 &#119A in the analytical capillary. During detection, the current was reduced to 40 &#119A. Linearity was observed from 0.50 to 12.0 mg/l with a coefficient of determination (r2) of 0.999. The limit of quantification was calculated to be 1.6 mg/kg. Sample preparation consisted of deproteination with acetic acid followed by centrifugation and filtration. The minimal sample pretreatment and relatively low running costs make isotachophoresis a good alternative to existing methods.
    European Food Research and Technology 04/2003; 216(5):440-444. · 1.39 Impact Factor
  • Source
    Jana Sádecká, Jozef Polonský
    [Show abstract] [Hide abstract]
    ABSTRACT: Nitrite, nitrate, iodide and thiocyanate have been quantified in non-smoker and smoker saliva by capillary isotachophoresis (CITP). Hydrochloric acid (10 mmol l(-1)) adjusted with histidine to pH 6.0 plus 6% poly(vinylpyrrolidone) was used as the leading electrolyte (LE) and 5 mmol l(-1) acetic acid as the terminating electrolyte (TE). Linearity was observed from 0.005 to 0.500 mmol l(-1) with a coefficient of determination (r(2)) of 0.999. The separation of anions was achieved in less than 19 min. The minimal sample pretreatment and relatively low running cost make isotachophoresis good alternative to existing methods.
    Talanta 04/2003; 59(4):643-9. · 3.50 Impact Factor
  • Jana Sádecká, Jozef Polonský
    [Show abstract] [Hide abstract]
    ABSTRACT: Nine organic acids and phosphate have been separated and quantified in tobacco by capillary isotachophoresis. Two operating systems for the separation were found: hydrochloric acid (10 mmol l(-1)) adjusted with beta-alanine to pH 2.9 plus 0.1% poly(vinylpyrrolidone) was used as the leading electrolyte and 10 mmol l(-1) nicotinic acid as the terminating electrolyte and hydrochloric acid (10 mmol l(-1)) including 5.5 mmol l(-1) 1,3-bis[tris(hydroxymethyl)methylamino]propane plus 0.1% poly(vinylpyrrolidone) was used as the leading electrolyte and 5 mmol l(-1) 2-morpholinoethanesulfonic acid as the terminating electrolyte. Linearity was observed from 0.008 to 0.100 mmol l(-1) with a coefficient of determination (r2) of 0.999. The separation of anions was achieved in less than 16 min. The minimal sample pretreatment and relatively low running cost make isotachophoresis a good alternative to existing methods.
    Journal of Chromatography A 03/2003; 988(1):161-5. · 4.61 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ibuprofen and naproxen have been quantified in tablets by capillary isotachophoresis. Hydrochloric acid (10 mmol/l) adjusted with creatinine to pH 5.0 plus 0.1% polyvinylpyrrolidone was used as the leading electrolyte and 10 mmol/l 4-morpholineethanesulfonic acid as the terminating electrolyte. Linearity was observed from 40.0 to 200.0 mg/l of ibuprofen (naproxen), with a coefficient of determination (r2) of 0.999. Good quantitation was obtained in short analysis time. The isotachophoretic results were compared with those obtained by the fluorescence spectrometry. Experimental parameters for ibuprofen were: lambdaEX=224 nm and lambdaEM=290 nm. Experimental parameters for naproxen were: lambdaEX=230 nm and lambdaEM=355 nm. The calibration plot was found to be linear in the range 0.4-2.4 mg/l for ibuprofen and 5.0-20.0 microg/l for naproxen. The minimal sample pretreatment and relatively low running cost make isotachophoresis a good alternative to existing methods.
    Journal of Pharmaceutical and Biomedical Analysis 08/2001; 25(5-6):881-91. · 2.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An isotachophoretic method with conductivity detection was developed to determine naproxen in the presence of its metabolite 6-O-desmethylnaproxen in human serum. The leading electrolyte contained 10 mM hydrochloric acid, beta-alanine, pH 4.0 and 0.1% methylhydroxypropylcellulose. The terminating electrolyte was 10 mM 2-(N-morpholino)ethanesulfonic acid-tris(hydroxymethyl)aminomethane, pH 6.9, containing 20% (v/v) of ethanol. Naproxen was determined in serum supernatant after simple deproteination of the sample with ethanol. The isotachophoretic results were compared with those obtained by synchronous fluorescence spectrometry.
    Journal of Chromatography A 06/2001; 916(1-2):207-14. · 4.61 Impact Factor
  • Jana Sádecká, J. Polonský
    [Show abstract] [Hide abstract]
    ABSTRACT:  A isotachophoretic method with conductivity detection was developed to directly determine ascorbic acid in food samples. The leading electrolyte contained hydrochloric acid (10 mmol/l), β-alanine (pH 3.0), and methylhydroxyethylcellulose (0.1%). The terminating electrolyte was 5 mmol/l caproic acid. The method is suitable for determining ascorbic acid in juice, beers, and as additives to meat products. The method was also applied for the determination of isoascorbic acid in additives to meat products.
    European Food Research and Technology 02/2001; 212(4):511-517. · 1.39 Impact Factor