Ein polarographisches Verfahren zur Bestimmung phenolischer Antioxydantien in Nahrungsfetten mit Hilfe einer rotierenden Graphitelektrode

Abstract

Es wird eine polarographische Methode zur Bestimmung von Antioxydantien in Nahrungsfetten beschrieben. Die d a m verwendete rotierende Graphitelektrode kann mit einfachen Mitteln selbst zusammengestellt werden. Das Verfahren eignet sich zur quantitativen Bestimmung von Antioxydantien in Fetten van 0.01 bis 0.020/0. Qualitative Aussagen sind nur bedingt moglich. 2,6-ditert.-Butyl-p-kresol kann nicht bestimmt werden.MBthode polarographique pour le dosage des antioxyghes phBnoliques dans les corps gras alimentaires B I'aide d'une Blectrode rotative en graphite On decrit une methode polarographique pour le dosage des antioxygenes dans les corps gras alimentaires. L'electrode rotative en graphite utilisee a cette fin, on peut l'assembler soimeme, avec des moyens simples. La methode convient pour le dosage des antioxygenes dans les corps gras de 0.01 a 0.02 O/o. Les affirmations qualitatives ne sont possibles que sous certaines reserves. L e 2,6-di-tert.-butyl-p-cr~.sol ne peut pas &tre dose.

Rapid voltammetric method for the estimation of tocopherols and antioxidants in oils and fats

“…The electrochemical behavior of pure solutions of phenolic antioxidants has been reported (7,8) but only rarely have methods been developed for analysis of real samples (9,10).…”

Organic polarography

“…Cyclic voltammetry was used to investigate the redox properties of 2,6-dialky 1-4-alkoxy phenols in acetonitrile (808), of catechol in H2SO4 (916), and of [3,4-(CH30)2C6-H3CH2]2 (705). Phenolic antioxidants such as propylgallate, and 2,6-di-ier<butyl-p-cresol in fats were determined voltammetrically at a graphite electrode (261). Anodic data for methoxybenzene derivatives were correlated to rate of photooxidation (790).…”

Voltammetric Behavior and Determination of Nordihydroguaiaretic Acid in Presence of Other Antioxidants Using PLS Calibration

“…Also, the orthogonality of the different principal components (PCs) allows to solve the problem of the collinearity present in the other methods, and the attenuation of the noise due to the elimination of the smallest PCs. The optimum number of factors depends not only on the number of independently varying chemical species presents, but also on other sources of systematic signal variation: randomly varying baselines, interaction between pure components or between processes in the electrode surface, etc..On the other hand, PLS and PCR methods have been essentially devised to model linear information but they can also describe non-lineal systems by incorporating more PCs than those necessary to describe linear systems [16,17] or by using new non-linear versions of PCR and PLS algorithms [18,19]. All these problems are more frequent when voltammetric signals due to irreversible processes are used.…”

“…Most methods determine NDGA in the presence of the others antioxidants in foods by chromatographic techniques [2 ± 7], or spectrophotometric methods [8 ± 15]. Regarding voltammetric techniques, Franzke [16] determined the total content of the antioxidants PG, NDGA, BHT and TBHQ in fats. Due to the small difference between E 1/2 of PG and NDGA, it was not possible to perform individual analysis for them.…”