Use of a Constrained Mixture Design to Optimize a Procedure for Closed Vessel Microwave-Assisted Digestion of Vegetal Leaves

Title:Use of a Constrained Mixture Design to Optimize a Procedure for Closed Vessel Microwave-Assisted Digestion of Vegetal Leaves

Volume: 4 Issue: 1

Author(s): Jacira T. Castro, Marcos A. Bezerra, Moisés A.L. Neto, Maria G.A. Korn, Cleber G. Novaes and Ricardo E. Santelli

Affiliation:

Keywords: Constrained mixture design, final acidity, ICP OES, metal, microwave-assisted digestion, residual carbon, vegetal leaves.

Abstract: Background: Reliable analytical methods for metals determination in tea is a demand of the nutritional and toxicological sciences. In this work, a constrained mixture design has been applied to develop an efficient closed-vessel microwave-assisted digestion procedure for Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn determination in vegetal leaves used for tea preparation.

Methods: The optimization step was carried out using a constrained mixture design to find digested samples of good characteristics such as clarity, low residual carbon and low final acidity. The studied metals and residual carbon were determined by simultaneous inductively coupled plasma optical emission spectrometry (ICP OES).

Results: The optimum proportions found by applying the mixture design were 31.3, 56.2 and 12.5% (v/v) for H₂O, HNO₃ and H₂O₂, respectively. The accuracy of the method was confirmed by analysis of two certified reference materials: apple leaves (NIST 1515) and spinach leaves (NIST 1570a). The proposed method was applied for the determination of studied metals in vegetal leaves used for the preparation of infusions.

Conclusion: The developed method has presented adequate analytical characteristics to determining of studied elements from tea samples with quickly, accuracy, precision and reliability.

Cite this article as:

Castro T. Jacira, Bezerra A. Marcos, Neto A.L. Moisés, Korn G.A. Maria, Novaes G. Cleber and Santelli E. Ricardo, Use of a Constrained Mixture Design to Optimize a Procedure for Closed Vessel Microwave-Assisted Digestion of Vegetal Leaves, Current Microwave Chemistry 2017; 4 (1) . https://dx.doi.org/10.2174/2213335603666160407211752

DOI https://dx.doi.org/10.2174/2213335603666160407211752	Print ISSN 2213-3356
Publisher Name Bentham Science Publisher	Online ISSN 2213-3364