Iron (Fe) is one of the most important elements in environmental and biological systems. It is found as both Fe(II) and Fe(III) forms in the nature [1,2]. Iron in small amounts is an essential element for the life on Earth, including humans and animals. On the other hand, iron in excess levels can cause several serious health Problems [3]. Therefore, it is very important to develop simple and sensitive methods for routine and quantitative determination of trace Fe in various matrices. Here, a simple and sensitive method has been proposed to determine total Fe in different kinds of real samples. The method consists of a vortex-assisted liquid-liquid microextraction step followed by UV-Vis spectrophotometric measurement. The procedure is based on complex formation of Fe(II) with O-phenanthroline. The complex forms an inert ion-association with tetraphenylborate as an counter anion which can be extracted into the 1,2 dichloroethane organic phase by the assistance of a vortex generator. The red colored complex iron present in the organic phase is then transferred to a micro-cuvette with 1 cm pathlength and the absorbance is measured at the wavelength of 510 nm. The effects of several parameters relevant to complex formation and microextraction steps such as the type and the volume of the organic solvent, the concentration of O-phenantroline and tetraphenylborate, the pH of the solution (donor phase), the extraction time and the stirring speed have been investigated and optimized. Under the optimized conditions, a good linearity was obtained for Fe(II) within the concentration range of 0.025 to 100 ngL-1. Also, the effects of several potential interferences were investigated which shows that the method responds selectively to iron. Finally, the method was successfully applied for determination of iron in pharmaceutical preparations and also spiked water samples. The recoveries were ranged from 92 to 106%.

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