Determination of some inorganic metals in edible vegetable oils by inductively coupled plasma atomic emission spectroscopy (ICP-AES)

Erol Pehlivan,M Musa Özcan,Fethiye Gode,Turkan Altun,Gulsin Arslan

doi:10.3989/gya.2008.v59.i3.514

Abstract

Seventeen edible vegetable oils were analyzed spectrometrically for their metal (Cu, Fe, Mn, Co, Cr, Pb, Cd, Ni, and Zn) contents. Toxic metals in edible vegetable oils were determined by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The highest metal concentrations were measured as 0.0850, 0.0352, 0.0220, 0.0040, 0.0010, 0.0074, 0.0045, 0.0254 and 0.2870 mg/kg for copper in almond oil, for iron in corn oil-(c), for manganese in soybean oil, for cobalt in sunflower oil-(b) and almond oil, for chromium in almond oil, for lead in virgin olive oil, for cadmium in sunflower oil-(e), for nickel almond oil and for zinc in almond oil respectively. The method for determining toxic metals in edible vegetable oils by using ICP-AES is discussed. The metals were extracted from low quantities of oil (2-3 g) with a 10% nitric acid solution. The extracted metal in acid solution can be injected into the ICPAES. The proposed method is simple and allows the metals to be determined in edible vegetable oils with a precision estimated below 10% relative standard deviation (RSD) for Cu, 5% for Fe, 15% for Mn, 8% for Co, 10% for Cr, 20% for Pb, 5% for Cd, 16% for Ni and 11% for Zn.

Highlights

Vegetable oils are widely used in the cooking and food processing, cosmetics, pharmaceutical and chemical industries (Dugo et al, 2004)
While the effects of chronic exposure to trace amounts of some metals are not well understood, many incidents tells us about the seriousness of high levels of exposure to some toxic metals, especially cadmium, chromium, cobalt, nickel and lead (Buldini, Ferri, & Sharma, 1997; Demirbas, 2001; Garrido et al, 1994)
In this paper we report an investigation on the feasibility of the direct extraction of toxic metals from vegetable oils using a dilute nitric acid solution before inductively coupled plasma atomic emission spectroscopy (ICP-AES)

Summary

Introduction

Vegetable oils are widely used in the cooking and food processing, cosmetics, pharmaceutical and chemical industries (Dugo et al, 2004). Plants and animals depend on some metals as micronutrients. Metal elements such as Na, K, Ca, Mg, Fe, Cu, Zn and Mn, are essential nutrients for human growth. Certain forms of some metals can be toxic, even in relatively small amounts, and pose a risk to the health of animals and people. Metal elements such as Cd, Pb, Cd, Co, and Cu, could have detrimental effects on health. While the effects of chronic exposure to trace amounts of some metals are not well understood, many incidents tells us about the seriousness of high levels of exposure to some toxic metals, especially cadmium, chromium, cobalt, nickel and lead (Buldini, Ferri, & Sharma, 1997; Demirbas, 2001; Garrido et al, 1994)

Methods

Results

Conclusion