Determination of Iron and Copper in Edible Oils by Flame Atomic Absorption Spectrometry After Liquid–Liquid Extraction

Abstract

such as inductively coupled plasma atomic emission spectrometry (ICP-AES) [2,4,5], inductively coupled plasma mass spectrometry (ICP-MS) [6], flame atomic absorption spectrometry (FAAS) [7,8], adsorptive stripping square wave voltammetry (Ad-SSWV) [9] and derivative potentiometric stripping analyses (dPSA) [10,11]. Most of these detection techniques require sample pretreatments involving the addition of one or more organic reagents, extraction with acids or acidic mixtures, wet digestion or dry ashing for eliminating the matrix effect. These sample pretreatment procedures are time consuming, prone to contamination and involve potential risks such as analyte losses, impoverishment of the overall LOD as a result of dilution of sample and the use of dangerous acid or acid mixtures. Neutron activation analysis (NAA) [12] and graphite furnace atomic absorption spectrometry (GFAAS) [3,5] has been used to analyze edible oils requiring no sample preparation. However, such expensive instrumentation is not commonly available.There have been many reports about Schiff bases and related complexes for the determination of certain metals in biological, clinical, nutritional, environmental and industrial samples [13][14][15][16][17][18][19][20][21]. In the present work, a new method was improved for the determination of Fe(III) and Cu(II) in edible oils without any digestion procedure. For this purpose, a new water-soluble Schiff base (Fig. 1) was synthesized, characterized [22] and utilized as a complexation reagent for the extraction of Fe(III) and Cu(II) from oil phase to aqueous phase. Materials and Methods Reagents and ChemicalsMerck Titrisol 109972 iron stock solution (1,000 mg iron L −1 ; FeCl 3 in 15 % HCl) (Darmstadt, Germany) andAbstract In the present work, a novel and rapid extraction method for Fe(III) and Cu(II) from liquid edible oils is described. N,N′-Bis(4-methoxysalicylidene)-1,2-diamino ethane (MSE) was utilized for the extraction of metal ions and the determination was achieved by flame atomic absorption spectrometry (FAAS). In order to optimize the extraction conditions, a central composite design (CCD) technique was employed. The optimum conditions, the ratio of MSE solution volume to oil mass, stirring time and temperature, were determined as 1.2 and 1.1 mL g −1 ; 24.0 and 31.8 min and 25.3 and 33.2 °C for Fe(III) and Cu(II) extraction, respectively. The feasibility of the improved method was tested with oil-based metal standards affording 98.6 % recovery for both metals and 67.3 ng g −1 for Fe(III) and 15.3 ng g −1 for Cu(II) as limit of detection (LOD).

Determination of Ni and Zn in an Oil Matrix using Schiff Base‐Assisted Extraction Followed by a Flame Atomic Absorption Spectrometer: A Simple Strategy to Determine Ni and Zn

“…The strategy comes to the forefront with speed and ease of application. In addition, LLE provides reduced reagent consumption, usage of nontoxic substances, and high analyte recovery rates as advantages (Köse Baran & Bağdat Yaşar, , ; Tokay & Bağdat, , ).…”

Development of UV-Vis Spectrophotometric Method for Rapid Nickel Determination in Original Oil Matrix

“…Briefly, aqueous phase including chelating agent is mixed with oil sample and the blend is mechanically stirred to transfer trace elements from oil phase to aqueous phase. Despite being an environmentally friendly, this non-destructive technique is time consuming [12][13][14].…”

Microemulsion as Sample Preparation for Direct Flame Atomic Absorption Spectrometry (FAAS) Determination of Total Iron in Crude and Refined Vegetable Oils

“…Traditional analytical methods to determine trace Fe in vegetable oils are mainly based on the use of instrumental techniques, such as flame atomic absorption spectrometry (FAAS), 9,10 electrothermal atomic absorption spectrometry (ETAAS), 11 inductively coupled plasma optical emission spectrometry (ICP OES) 2,12 and inductively coupled plasma mass spectrometry (ICP-MS). 13 In most instances, these techniques have been applied in association with various types of sample pretreatments before the analysis, aimed to reduce matrix and spectral interferences and increase the availability of the trace metals for determination in viscous liquid samples containing a high organic content, such as vegetable oils.…”

“…2 Most of the sample treatment procedures applied in the analysis of vegetable oils are based on liquid-liquid extraction, 10 acid extraction, 11,18 extraction induced by emulsion breaking, 13 ultrasound assisted extraction, 5,6 emulsification 19,20 and microemulsification. 3 Among these, microemulsification has emerged as a suitable and promising sample pretreatment procedure for direct analysis of samples with a high organic content, such as vegetable oils, diesel, 21 biodiesel, [22][23][24][25] lubricating oil, 26,27 and fuels.…”