Determination of essential elements (Mn, Fe, Cu and Zn) in herbal teas by TXRF, FAAS and ICP‐OES

Abstract

The aim of this study was the comparison of the results obtained in the determination of the content of essential elements such as Mn, Fe, Cu and Zn in vegetation samples using different analytical approaches, including suspension preparation and total reflection X-ray fluorescence (TXRF) analysis as well as most commonly used spectroscopic methods in the field of vegetal analysis such as acid digestion in combination with atomic emission (AES) and atomic absorption spectrometry (AAS). In the case of TXRF analysis, two instruments equipped with different X-ray tubes anodes (W and Mo) were used to better evaluate the potential of TXRF for vegetal samples analysis. Analytical figures of merit for the considered methods were determined by the analysis of plant reference materials. The one-way analysis of variance (ANOVA) applied to the analysed and certified values showed that the results were not statistically different at the significance level of p-values <0.05. Therefore, suspension preparation and TXRF analysis proved to be a sustainable and fast analytical alternative to the most commonly used ones involving a previous digestion of the sample and inductively coupled plasma optical emission spectrometry (ICP-OES) or flame atomic absorption spectrometry (FAAS) analysis. Finally, the different analytical approaches were applied to the determination of Mn, Fe, Cu and Zn in a set of herbal teas used for medical purposes.

Determination of nutrient and toxic elements in food reference materials by suspension preparation and TXRF analysis

“…This suggested that TXRF had high precision when determining trace elements in various SRM (SL, TD, OT, and BM) sample matrices. For real vegetation, food, fish, and meat samples, several parameters such as particle size, fat, or protein content need to be taken into account to obtain homogeneous suspension, and gain a precise and accurate result (Dalipi et al, 2017a;Marguí et al, 2021).…”

Atomic spectrometry update: review of advances in X-ray fluorescence spectrometry and its special applications

“…Whereas the ICP-AES and FAAS analysis of suspensions of herbal tea and plant leaf CRMs required 63 sample digestion, the use of TXRF spectrometry made direct analysis possible. The TXRF analysis did not require ultra-pure gases and could give results for 10–50 mg of sample in as little as 15–40 min.…”

Separation and determination of lithium and manganese ions in healthy humans and multiple sclerosis patients based on Nano graphene oxide by Ultrasound assisted-dispersive -micro solid-phase extraction

“…The Li in human samples was determined by high-resolution atomic absorption spectrometry (HR-AAS) and machine learning data(MLD) [14]. In addition, Mn ions in herbal teas were evaluated by FAAS and ICP-OES [15]. The cation exchange chromatography coupled to field ICP-MS was used for Mn determination in cerebrospinal fluid [16].…”