Multivariate approaches applied to optimization of an ultrasound-assisted extraction procedure for determination of essential elements in guarana samples by ICP OES

Abstract

In the present work, a simple and high-throughput analytical procedure based on ultrasound-assisted extraction with diluted acid was proposed for the determination of Ca, Mg, K, P, S, Fe, Cu and Mn in guarana samples using inductively coupled plasma optical emission spectrometry. Two multivariate approaches were employed for optimization of the extraction procedure: mixture and Doehlert designs. The best experimental conditions were established by application of a multi-response function (overall desirability). An extractor medium composed of diluted nitric acid was selected for analytes extraction. Optimized conditions for ultrasound-assisted extraction followed the temperature of 60 °C, sonication time of 10 min and power of 100% applied to the ultrasonic bath. After the analytical validation step, the proposed procedure was successfully employed for determination of essential elements in thirty-three guarana samples from the state of Bahia, Brazil. Mass fractions higher than 0.42% (m m -1 ) were found for potassium in all analyzed samples. For the other macro-elements, the mass fraction ranged from 514 mg kg -1 (magnesium) to 0.19% m m -1 (calcium). The mass fraction of micro-elements ranged from 5.1 to 91.3 mg kg -1 for cooper and iron, respectively.

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…Several procedures involving ultrasound-assisted extraction have been developed. For the ICP-OES determination of Ca, Cu, Fe, K Mg, Mn, P, S, in guarana, Farias et al 69 devised an ultrasonic bath procedure in which 300 mg of sample was extracted with 10 mL of 1.4 mol L −1 HNO 3 at 60 °C, with 100% power applied for 10 min. After centrifuging, a 1 mL sub-sample was diluted to 10 mL (for the determination of K, Mg, P and S) or to 2.5 mL (for the determination of Cu, Fe and Mn).…”

Design of Experiments for Optimizing Ultrasound-Assisted Extraction of Bioactive Compounds from Plant-Based Sources

“…It is also known as the Uniform shell design. DD is derived from a spherical domain with an orthogonal array and is a not-rotatable DOE [146]. This design is generated from regular geometric shapes with k + 1 vertices (k-dimensional simplexes), circumventing a central point indicating an optimal region [67].…”

“…Furthermore, the best condition for sonication time was 10 min, using 15 mL of extractor volume. Also, this DOE has been investigated to optimize the time, temperature, and power ultrasound conditions during the UAE of essential elements (Ca, Mg, K, P, S, Fe, Cu, and Mn) in guarana samples [146].…”