Multivariate Optimization for the Development of a Fast and Simple Ultrasound-Assisted Extraction Procedure for Multielemental Determination in Tea Leaves by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES)

Abstract

The current study describes a fast and efficient procedure of ultrasound-assisted extraction for determination of Ca, Mg, K, Na, Cu, Zn, Mn, and Al in tea leaves by inductively coupled plasma optical emission spectrometry (ICP OES). The variables of procedure were optimized using the Box-Behnken design and the conditions selected were nitric acid concentration (1.0 mol L −1), sonication time (7 min), and sonication temperature (75°C). The extraction efficiency was calculated using the analyte concentration obtained by a total digestion procedure as reference. Accuracy was confirmed by analysis of certified reference material of apple leaves (NIST 1515) and spinach leaves (NIST 1570a) using the procedure proposed. A statistical evaluation using Student's t test showed that there is no significant difference between the value obtained with the proposed procedure and the certified value, at 95% confidence level. The proposed procedure was successfully applied and is a good alternative to conventional acid digestion procedure and can be applied to routine analysis for determination of Ca, Mg, K, Na, Zn, Mn, Cu, and Al in tea leaves used for the preparation of infusions.

Novel LIBS method for micro‐spatial chemical analysis of inorganic gunshot residues

“…Parameters were chosen that resulted in the highest increase of the SNR for both Pb and Ba. When the data is a good fit for the Box‐Behnken design, then the mean square of lack of fit should reflect only the random error in the model and not be statistically different from the mean square of the pure error; in other words, the two errors should be comparable 40 . The P value for the design was greater than the alpha level of 0.05 and indicated the difference between the model data and the experimental data was not significantly different.…”

Direct determination of nutrient elements in plant leaves by double pulse laser-induced breakdown spectroscopy: evaluation of calibration strategies using direct and inverse models for matrix-matching

“…2 Consequently, elemental analysis of plant tissues is essential from an agronomic point of view in sustainable and physiological studies. 3,4 Commonly, the assessment of nutrient element concentration in plant tissue is performed by spectroanalytical techniques, including ame atomic absorption spectrometry (FAAS), 5 inductively coupled plasma optical emission spectrometry (ICP OES), 6 and inductively coupled plasma-mass spectrometry (ICP-MS). 7 In general, these techniques require sample acid digestion to convert the solid material into a homogeneous aqueous solution.…”