Multivariate optimization of ultrasound-assisted extraction for determination of Cu, Fe, Ni and Zn in vegetable oils by high-resolution continuum source atomic absorption spectrometry

Abstract

An assisted liquid-liquid extraction of copper, iron, nickel and zinc from vegetable oil samples with subsequent determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was optimized by applying a full factorial design in two levels and the response surface methodology, Box-Behnken. The effects of the acid concentration and the amplitude, cycle and time of sonication on the extraction of the analytes, as well as their interactions, were assessed. In the selected condition (sonication amplitude = 66%, sonication time = 79 s, sonication cycle = 74%), using 0.5 mol L(-1) HCl as the extractant, the limits of quantification were 0.14, 0.20, 0.21 and 0.04 μg g(-1) for Cu, Fe, Ni and Zn, respectively, with R.S.D. ranging from 1.4% to 3.6%. The proposed method was applied for the determination of the analytes in soybean, canola and sunflower oils.

Removal of pomace residues is critical in quantification of element concentrations in extra virgin olive oil

“…The detection limits of ultrasonic acid extraction were below 0.2 ng g -1 for all trace elements, with the highest method sensitivity achieved for Cd, Ce, Co, Cs, La, Tl and Y (LOD values of 1 pg g -1 ) ( Table 3). The LOD values we obtained were comparable with the data obtained by ultrasonic extraction of EVOO using the same extraction method (Camin et al, 2010a, b), and were much better than obtained in other vegetable oils using similar extraction methods (Ni et al, 2016;Trindade et al, 2015).…”

“…Different sample preparation and extraction techniques have been used for element analyses in vegetable oils, including liquid-liquid extraction (Dugo et al, 2004), wet ashing (Lo Coco et al, 2003), dry ashing combined with acid extraction (Brkljača et al, 2013), microwave digestion (Angioni et al, 2006;Bakkali et al, 2012;Benincasa et al, 2007;Cindric et al, 2007;Mendil et al, 2009;Zeiner et al, 2010), simple dilution with a suitable solvent (Anthemidis et al, 2005;Castillo et al, 1999;De Souza et al, 2005;Jimenez et al, 2003), acid extraction in vortexed samples (Ni et al, 2016), and ultrasonic acid extraction (Camin et al, 2010b;Trindade et al, 2015). Among them, microwave digestion is the most commonly used extraction technique; however, it does not allow determination of elements at very low levels because of the limited amount of sample that can be processed (Lepri et al, 2011).…”

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 preferability of a novel method is quite important and may be scored by the detection technique, speed, cost of analysis, toxic reagent consumption, and quality of the analytical results. Considering the requirements, the suggested procedure was compared with the most recent studies using detection techniques, basis of the sample pretreatment, cost of equipment, and so on (Aşcı, Efendio glu, & Batı, 2008;Kara, Fisher, & Hill, 2015;Nunes et al, 2011;Trindade, Dantas, Lima, Ferreira, & Teixeira, 2015;Zhuravlev et al, 2015) in Table 5. The outstanding features of the suggested work are cheap, simple, and compatible to alternative atomic spectroscopic techniques.…”

Análises Físico-Químicas Comparativas Entre Biodieseis Derivados De Óleos Vegetais E Um Diluente Asfáltico

“…Os óleos vegetais são utilizados pela humanidade desde a antiguidade seja na alimentação ou em aplicações tecnológicas diversas como na indústria química e farmacêutica. (LÓPEZ-GARCIA, VICENTE-MARTÍNEZ, HERNÁNDEZ-CÓRDOBA, 2014;DUGO, et al, 2004;ZHU, et al, 2011;TRINDADE, et al, 2015) Usualmente os óleos vegetais presentes na alimentação humana provem de sementes de vegetais como soja, girassol, milho e canola ou ainda de frutos como azeitona e palmeiras (GUNSTONE, 2011). A obtenção dos óleos vegetais pode ocorrer por extração com solvente orgânico ou prensagem mecânica das sementes ou frutos (BRASIL, 1993).…”

“…(DUGO, et al, 2004) Entre os procedimentos de preparo de amostras mais amplamente aplicados para determinação de metais em óleos estão: a digestão ácida em frasco aberto ou assistida por micro-ondas, combustão assistida por micro-ondas, emulsificação, extração líquido-líquido e diluição direta. (TRINDADE, et al, 2015;WELZ;SPERLING, 1999) A digestão ácida busca oxidar todos os compostos orgânicos constituintes da amostra utilizando misturas de reagentes como: ácido nítrico, ácido sulfúrico e peróxido de hidrogênio, sob altas temperaturas em frasco aberto ou em sistema microondas sob alta pressão, até a completa decomposição da matriz da amostra. (IAL, 2008; BADER, ZIMMERMANN, 2012) A digestão ácida apresenta vantagens como a eliminação de prováveis interferências da matriz, elevada aplicabilidade, eficiência e robustez.…”