Factorial Design Optimization of Microwave Digestion for Macro and Microelements in Pregnant Women and Diabetics Multivitamin/Multielement Preparations by Inductive Coupled Plasma Mass Spectrometry (ICPMS)

Abstract

In the present work, the microwave digestion procedure for the determination of Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Se, V and Zn in multivitamin/multielement (MVM) preparations used for pregnant women and diabetics employing ICP-MS, was optimized by factorial design 3 3 (27 runs). The microwave digestion conditions temperature (160, 180 and 200ºC), acid mixture volume (3.9, 5.2 and 6.5 ml) and radiation period (10, 15 and 20 min) were selected as factors. Moreover, a multiple response (MR) was built to establish a compromise conditions between the elements. The optimum conditions were found to be 160ºC, 6.5 ml, and 20 min for temperature, acid mixture volume and radiation period, respectively. The procedure was validated using standard reference material (SRM3280) and elements recoveries were found to be in the range 88 -107% and was applied to determination of Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Se, V and Zn in commercial MVM samples obtained from the local market.

Microwave-Assisted Digestion Using Dilute Nitric Acid and Hydrogen Peroxide for Multielement Determination in Wheat Flour by ICP-MS

“…At temperatures less than 190 °C, we observed that the solutions resulting from digestion were yellowish in color with suspended solid particles. Other studies have reported the same observation [30,31]. At temperatures above 215 °C, we observed explosive conditions inside the microwave equipment, probably because of H 2 O 2 decomposition [32].…”