Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

Abstract

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO 3 only and demonstrated good analytical performance, i.e., precision (0.80-5.0%), accuracy (< 5%), recoveries of elements (97.4-105%), and their detection limits (0.075-1.1 μg L −1 ) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)-40.7% (Ca) and 4.65% (Al)-46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

Novel ICP-OES-Based Method for the Reliable Determination of the Total Content of 15 Elements in Yerba Mate Drinks along with the Determination of Caffeine and the In Vitro Bioaccessibility of the Compounds

“…Regarding the available literature, the element analysis of yerba mate beverages concerned only the freshly prepared hot and/or cold tea infusions [4,5,[10][11][12][13]16,20,21]. Accordingly, this research work reports for the first time the multielement analysis (15) of the commercially available ready-to-drink yerba mate drinks. Despite this, the concentrations of elements determined in all examined YM drinks were within the ranges reported for the fresh YM tea infusions, i.…”

“…However, this may be wrong as the elements are assumed to be 100% available and absorbed by the body during intraoral digestion. In fact, real effects on human health can be assessed only after the estimation of the bioaccessibility of elements by an in vitro digestibility model with artificial enzymes that can be used to mimic physicochemical and enzymatic processes in the human gastrointestinal tract [14,15]. So far, the bioaccessibility of elements from YM is little described in the literature and focuses only on four elements (Al, Cd, Cu, Pb) present in infusions prepared [16].…”

Simplified ICP OES-Based Method for Determination of 12 Elements in Commercial Bottled Birch Saps: Validation and Bioaccessibility Study

“…Determination of bioaccessibility of elements in BSs was made with the aid of in vitro GID. A two-step procedure with SGJ and SIJ solutions were used to simulate GID as detailed before [15,16]. In brief, for in vitro GID, samples (aliquots (20.0 g, n = 3) of each BSs and water (treated as a blank)) were placed in 50-mL PP tubs, adjusted to pH 2.0 with a 6.0 mol L −1 HCl solution and filled with 3.0 mL of the SGJ solution to simulate gastric digestion.…”

“…In fact, actual nutritional benefits to human health associated with drinking of the BS can be assessed only after an estimation of the bioaccessibility of elements. In this case, an in vitro digestibility model with artificial enzymes can be used to mimic physicochemical and enzymatic processes in the human gastro-intestinal tract [15,16]. Consequently, the determination of total element contents may lead to overestimation of the coverage of their RDIs.…”

Exposure Assessment of Fluoride Intake Through Commercially Available Black Tea (Camellia sinensis L.) from Areas with High Incidences of Chronic Kidney Disease with Undetermined Origin (CKDu) in Sri Lanka

“…Although only a fraction of F − becomes absorbed by the gastro-intestinal system, additional F − intake via tea infusions worsens exposure levels [6]. This makes it an important source of dietary intake [6,37]. In addition, when waters with elevated F − contents are used for preparing infusions, the contents of this critical element can further increase [7,27].…”