Use of Mixture Design with Minimal Restrictions to Optimize an Extraction Procedure Employing Diluted Acids Assisted by Ultrasound and Microwave for Nutrient Element Determination in Vegetal Samples

Vinícius Costa,Fábio Amorim,Daniel Lima,Marcelo Franco,Erik Silva,Marcos Bezerra,Raildo Jesus

doi:10.21577/0103-5053.20170214

Vinícius Costa, Fábio Amorim + Show 5 more

Open Access

https://doi.org/10.21577/0103-5053.20170214

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Abstract

In this work, it was developed an alternative analytical strategy for the preparation of vegetal samples extracted with diluted acids and assisted by ultrasound and microwave radiation for the determination of nutrients elements by fast sequential flame atomic absorption spectrometer. The conditions optimized using univariate and multivariate methodologies for the procedure were as follows: 200 mg of sample; extraction solution comprising a mixture of 6.3 mL HNO3, 2.1 mL HCl, and 1.7 mL CH3COOH; extractor with a final concentration of 2.5 mol L-1; a sonication time of 30 min; and a microwave radiation time of 6 s. The accuracy of the procedure was confirmed by analyzing the certified reference material NIST 1515 (apple leaves) and by comparison with the results obtained through microwave-assisted total digestion method. The procedure was applied to determine Ca, Mg, Cu, Mn, Fe, and Zn in several cassava peel samples used in animal nutrition, and proved to be simple, reliable, fast, easy to implement, and inexpensive.

Highlights

The most commonly used analytical techniques for the elemental determination of complex samples are flame atomic absorption spectroscopy (FAAS), inductively coupled plasma optical emission spectrometry, and inductively coupled plasma mass spectrometry.[1]
One of the most important trends in sample preparation is the interest in analytical procedures that complies with the principles of green chemistry
These results demonstrated that the external calibration method can be satisfactorily employed for determination of elements studied in cassava peels samples by fast sequential (FS) FAAS

Summary

Introduction

The most commonly used analytical techniques for the elemental determination of complex samples are flame atomic absorption spectroscopy (FAAS), inductively coupled plasma optical emission spectrometry, and inductively coupled plasma mass spectrometry.[1]. One of the most important trends in sample preparation is the interest in analytical procedures that complies with the principles of green chemistry. Following this trend, the use of diluted acids has been shown to present significant advantages such as cost reduction, production. Considering the advantages of diluted acids, a range of recent applications have demonstrated their potential in sample preparation, e.g., employing digestion-assisted microwave for several samples, such as beans,[5] pâté,[6] milk and beef,[7] honey,[8] biological matrices,[9] milk,[10] chocolate,[11] plants,[12] and fertilizers.[13]

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