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The effects of pH and surfactants on the absorption and fluorescence properties of ochratoxin A and zearalenone
Author(s) -
Li Taihua,
Kim Bo Bae,
Ha Tae Hwan,
Shin YongBeom,
Kim MinGon
Publication year - 2015
Publication title -
luminescence
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 45
eISSN - 1522-7243
pISSN - 1522-7235
DOI - 10.1002/bio.2866
Subject(s) - chemistry , fluorescence , ochratoxin a , sodium dodecyl sulfate , aqueous solution , pulmonary surfactant , absorption (acoustics) , mycotoxin , cationic polymerization , ionic bonding , chromatography , organic chemistry , ion , materials science , biochemistry , physics , food science , quantum mechanics , composite material
The pH and surfactant dependencies of the absorption and fluorescence properties of ochratoxin A (OTA) and zearalenone (ZEN), the main mycotoxins found as contaminants in foods and feeds, were evaluated. Three surfactants with different ionic properties were investigated, namely sodium dodecyl sulfate (SDS, anionic), Tween 20 (nonionic) and hexadecyltrimethylammonium bromide (CTAB, cationic). The results show that the effects of pH on the absorption wavelength maxima and fluorescence efficiencies of the mycotoxins, which are a consequence of the presence of acidic phenol and/or carboxyl containing fluorophores, are dependent on the ionic nature of the added surfactants. Specifically, the fluorescence responses to pH changes of OTA and ZEN are similar in the presence or absence of Tween 20 and SDS. By contrast, the pH‐dependent fluorescence properties of these mycotoxins are altered when CTAB is present in the solutions. Moreover, unlike OTA, ZEN in aqueous solution displays almost no fluorescence. However, fluorescence enhancement takes place when surfactants are present in aqueous solutions of this mycotoxin. The results of this study demonstrate that the different microenvironments, present in the organized micellar systems created by the individual surfactants, can be potentially employed to modulate the sensitivities and selectivities of the fluorescence detection of OTA or ZEN. Copyright © 2015 John Wiley & Sons, Ltd.