Naslov
Simultaneous determination of Binary Dye Mixtures in Food Samples by Three Spectroscopic Methods

Autori
Palčić, Marina ; Ilijaš, Darija ; Pranjić, Ivana ; Grabarić, Božidar S. ; Grabarić, Zorana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
YISAC 2010, Venice / - , 2010

Skup
YISAC 2010

Mjesto i datum
Venecija, Italija, 29.06.2010. - 02.07.2010

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
signals ratio resolution method; Vierordot's method; derivative method; spectrophotometry; food dye; binary mixture

Sažetak
For resolution of overlapping signals there are methods based on purely mathematical curve resolution techniques using logarithmic, Fourier or derivative transformations, the last one being improved using measurement at selected “zero-crossings” of derivative, mainly spectrophotometric, signals. For signals and systems where conventional resolution techniques are not very suitable, multivariate calibrations using a family of factor analysis techniques can be used as general selectivity and reliability enhancement tools. In this work a simple method based on signals ratio resolution (SRS) has been fully investigated and some new criteria are established, which enable the determination of two components in mixture from one set of the experimental data. The procedure consists of using several different resolving functions and plotting the difference of the mean of absolute and nonabsolute values of pseudosignals [PDMMV(PS) against analyte concentration obtained with each of the resolving functions, thus obtaining 2 straight lines having intersections that give a concentration of individual dye in binary mixture. The results obtained with SRS method were compared with Vierordt’s method in which absorbances of the mixed sample solutions were measured and then the concentration of each compound was calculated from the following simultaneous equations: A1 = 1 c1 + 1 c2 A2 = 2 c1 + 2 c2 where c1 and c2 are the concentrations of two dyes, A denotes the absorbance of the mixture solution, and  and  represent the values of A (1%, 1 cm) for individual dye. The assay precision of this method depends on the selection of wavelengths (). A number of criteria can be used to select  and to decrease estimation errors for components in mixtures with both low and high contents. A first-derivative spectrophotometric method using a zero-crossing technique of measurement for simultaneous determination of binary dye mixture was used, too. The increased selectivity in derivative spectrophotometry results because bands that are overlapped in zero-order absorption spectra can be separated in the derivative mode. Mean recoveries, relative standard deviations and linearity ranges in calibration graphs of the methods are compared and discussed.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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