Determination of Natamycin in Dairy Products Using Dispersive Liquid-Liquid Microextraction and Indirect Flame Atomic Absorption Spectrometry

In this paper, a dispersive liquid-liquid microextraction method has been developed for the extraction and preconcentration of natamycin from cheese and doogh samples and its determination by indirect flame atomic absorption spectrometry. For this purpose, an appropriate mixture of a disperser solvent (ethanol) and an extraction solvent (1,1,2-trichloroethane) is rapidly injected into the samples and Zn2+ cation was added. During this process, natamycin-Zn complex is extracted into fine droplets of the extraction solvent. After centrifugation, the fine droplets of the extractant containing the complex are sedimented at the bottom of a tube with conical bottom. The sedimented phase is injected into the determination system via a home-made sample introduction system. Under the optimal conditions, the linear range was between 5 and 1000 ng mL−1. The limit of detection of the target analyte was obtained 1.8 ng mL−1. The relative recoveries obtained for the spiked cheese and doogh samples were between 86 and 98%. Moreover, the precision of the method was acceptable (<3.9%) in all spiked concentrations. Finally, the method was successfully applied to determine natamycin in cheese and doogh samples.