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Papers by María Eugenia Centurión

Determining fat content in hamburgers is very important to minimize or control the negative effec... more Determining fat content in hamburgers is very important to minimize or control the negative effects of fat on human health, effects such as cardiovascular diseases and obesity, which are caused by the high consumption of saturated fatty acids and cholesterol. This study proposed an alternative analytical method based on Near In-frared Spectroscopy (NIR) and Successive Projections Algorithm for interval selection in Partial Least Squares regression (iSPA-PLS) for fat content determination in commercial chicken hamburgers. For this, 70 hamburger samples with a fat content ranging from 14.27 to 32.12 mg kg −1 were prepared based on the upper limit recommended by the Argentinean Food Codex, which is 20% (w w −1). NIR spectra were then recorded and then preprocessed by applying different approaches: base line correction, SNV, MSC, and Savitzky-Golay smoothing. For comparison, full-spectrum PLS and the Interval PLS are also used. The best performance for the prediction set was obtained for the first derivative Savitzky-Golay smoothing with a second-order polynomial and window size of 19 points, achieving a coefficient of correlation of 0.94, RMSEP of 1.59 mg kg −1 , REP of 7.69% and RPD of 3.02. The proposed methodology represents an excellent alternative to the conventional Soxhlet extraction method, since waste generation is avoided, yet without the use of either chemical reagents or solvents, which follows the primary principles of Green Chemistry. The new method was successfully applied to chicken hamburger analysis, and the results agreed with those with reference values at a 95% confidence level, making it very attractive for routine analysis.

Microchemical Journal 112 (2014) 104–108

In this paper a geographic origin classification of honey samples from Argentina was proposed. Fo... more In this paper a geographic origin classification of honey samples from Argentina was proposed. For this reason, a conventional flow-batch system with a simple webcam to capture digital images was employed. In this methodology, analytical information is generated from color histograms obtained from the digital images employing different color models (RGB (red–green–blue), HSB (hue–saturation–brightness) and Grayscale). Three chemometric tools were employed for geographic origin classification (SPA-LDA (successive projections algorithm-linear discriminant analysis), SIMCA (soft independent modeling for class analogy), and PLS-DA (partial least squares-discriminant analysis)). The proposed method is a good option to be used in quality control laboratories for the classification of honey samples according to their geographical origin.

Microchemical Journal, 2013

$Research paper thumbnail of Picosecond electron diffraction from molecules aligned by dissociation$

Journal of Molecular Structure, 2010

Food Chemistry, 2005

The quantification of total creatinine contributes to the quality control in meat products. The r... more The quantification of total creatinine contributes to the quality control in meat products. The reference method for dehydrated broths treatment is tedious and takes approximately 6 h. A fast, simple and relatively safe procedure to the pre-treatment of these samples was developed by using a focussed microwave oven which works in continuous way. The optimization of the different variables for the pre-treatment was made and the validation of the method was carried out in order to ensure the accuracy of the obtained results.

Analytical Letters, 2006

In order to improve the quality control of dehydrated broth, a new automated method was developed... more In order to improve the quality control of dehydrated broth, a new automated method was developed to determine total creatinine in dehydrated broths. The sample pretreatment was coupled on‐line with the Flow Injection Analysis (FIA) system for analyte determination by the classical Jaffé reaction, stopped flow methodology, and spectrophotometric detection. The time consumed was reduced from 7 h, which is necessary

Analytical Letters, 2007

... Marcos Grünhut a , María E. Centurión a & Beatriz Fernández Band a * pages 2016-2031.... more ... Marcos Grünhut a , María E. Centurión a & Beatriz Fernández Band a * pages 2016-2031. ... Then, it was filtered on‐line by passing through a tubular cotton filter in FIA system. In order to validate the proposed method a recovery study was performed by spiked samples. ...

Analytical and Bioanalytical Chemistry, 2004

Several phenolic compounds are present in tobacco smoke. They are formed from the pyrolysis of to... more Several phenolic compounds are present in tobacco smoke. They are formed from the pyrolysis of tobacco during the smoking process and all of them are toxic. Therefore, the determination of these compounds in air samples is important. A rapid, simple, and sensitive method using a synchronous spectrofluorimetry technique was developed to quantify hydroquinone and resorcinol simultaneously. One of the advantages of this method is the simple and rapid sampling technique, which uses water as the absorption solution of the analytes in the air sample. The precision of the method (%RSD) was 1.8% and the detection limits were 0.125 mg m(-3) and 0.292 mg m(-3) for hydroquinone and resorcinol, respectively.

Analytica Chimica Acta, 2010

A combination of kinetic spectroscopic monitoring and multivariate curve resolution-alternating l... more A combination of kinetic spectroscopic monitoring and multivariate curve resolution-alternating least squares (MCR-ALS) was proposed for the enzymatic determination of levodopa (LVD) and carbidopa (CBD) in pharmaceuticals. The enzymatic reaction process was carried out in a reverse stopped-flow injection system and monitored by UV-vis spectroscopy. The spectra (292-600 nm) were recorded throughout the reaction and were analyzed by multivariate curve resolution-alternating least squares. A small calibration matrix containing nine mixtures was used in the model construction. Additionally, to evaluate the prediction ability of the model, a set with six validation mixtures was used. The lack of fit obtained was 4.3%, the explained variance 99.8% and the overall prediction error 5.5%. Tablets of commercial samples were analyzed and the results were validated by pharmacopeia method (high performance liquid chromatography). No significant differences were found (alpha=0.05) between the reference values and the ones obtained with the proposed method. It is important to note that a unique chemometric model made it possible to determine both analytes simultaneously.