Simple and Fast Sample Preparation Procedure Prior to Multi-element Analysis of Slim Teas by ICP OES

Abstract

The knowledge about mineral content of slim teas is of great importance since the consumption of these beverages has rapidly increased for the past several years. An increasing popularity of these tea products is mainly attributed to their nutritional properties, flavor, taste and health effects. Therefore, the main goal of the present work was to develop a precise and accurate method of the multi-element analysis of slim teas by inductively coupled plasma optical emission spectrometry (ICP OES) without the need for a laborious and tedious sample treatment preceding spectrometric measurements. Five sample preparation procedures, i.e., the total decomposition in a mixture of HNO 3 and H 2 O 2 solutions using closed vessel microwave-assisted or open vessel hot-plate systems, the solubilisation in aqua regia or a tetramethyl ammonium hydroxide solution and the extraction in a diluted HNO 3 solution, were compared. The performance of the compared procedures was determined in terms of the precision and the accuracy of results achieved and limits of detection of elements. It was found that the solubilisation in aqua regia gave the best results, i.e., limits of detection between 0.15 and 98.4 ng l −1 , the precision within 0.6−3.0 % and the accuracy better than 5 %. The developed method of the analysis, being a useful alternative to timeconsuming wet digestion procedures, was successfully applied to the analysis of five slim tea products.

Determination of essential and non-essential elements in green and black teas by FAAS and ICP OES simplified – multivariate classification of different tea products

“…As compared to the recently published work [23], the mentioned sample preparation procedure was extended to such complex matrices as black and green teas and used for determining 16 metals (Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn) in bagged and leaf teas by FAAS and ICP OES. The proposed method and can increase the sample through-put and save the time of the multi-element analysis and may particularly be used for routine analyses of a great number of tea samples that are commonly decomposed prior to spectrochemical measurements by wet or dry ashings.…”

“…The precision was also given as the relative standard deviation (RSD) of results and compared between all procedures used. The accuracy of results was evaluated by the statistical comparison of concentrations of metals obtained using the procedure P1 to those obtained using proposed P2, P3, P4 and P5 procedures [23]. When no statistically significant differences (F calculated b F critical ) were found between SDs of results, the twosample Student t-test was used to compare average concentrations of metals [24].…”

“…Recently in our laboratory, the suitability of 5 different sample preparation procedures, including the closed-vessel microwaveassisted wet digestion, the open-vessel hot-plate wet digestion, the ultrasound-assisted solubilisation in aqua regia at room temperature, the solubilisation in TMAH at 80°C and the ultrasound-assisted extraction in a 1.0 mol L −1 HNO 3 solution at 50°C was evaluated in reference to the simultaneous determination of 12 metals (Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr and Zn) by ICP OES in bag slim teas [23]. The objective of the present contribution, being the continuation of the cited research, was to simplify the sample preparation procedure of bagged and leaf black and green teas (BTBs and BTLs and GTBs and GTLs) by avoiding the wet digestion prior to the simpler and faster routine multi-element analysis of these products by FAAS (Ca, Fe, K, Mg, Mn and Na) and ICP OES (Al, Ba, Cd, Co, Cr, Cu, Ni, Pb, Sr and Zn).…”

Determination of Minerals in Herbal Infusions Promoting Weight Loss

“…The results obtained in this study and by other authors suggest that Ca and Mg are present in medicines of plant origin and teas with varied composition (herbs, teas, fruits, bioactive ingredients) in considerable amounts [2, 13, 14]. Garcinia cambogia widely used as a component of slimming formulations can be an example .…”

Solid phase extraction of metal ions in environmental samples on 1-(2-pyridylazo)-2-naphthol impregnated activated carbon cloth

“…Hence, the development of fast, reliable and effective analytical methods for the determination of trace amounts of lead, cadmium and nickel in real samples is an important area of research Soylak et al, 2007;Tuzen et al, 2009;Tajik and Taher, 2011;Acar et al, 2014;Szymczycha-Madeja et al, 2014).…”