Determination of essential and non-essential elements in herbal tea and camomile by polarised X rays fluorescence spectrometer (EDPXRF)

Features of sample preparation techniques in the total-reflection X-ray fluorescence analysis of tea leaves

Tea is a popular drink around the world and contains essential minerals and trace elements for human health. In this study, the analytical capabilities of the total-reflection X-ray fluorescence method (TXRF) were considered for the analysis of tea. Different sample preparation techniques, e.g. suspension, open vessel acid digestion, and microwave acid digestion were examined. The influence of particle size was investigated in the analysis of the suspension of tea samples. Mass-absorption coefficients for the tea matrix and the critical surface density of the specimen were calculated. The data obtained explain the presence of absorption effects in the determination of P, S, Cl, and K in suspensions. The digestion procedure is chosen as an optimal sample preparation technique for the TXRF analysis of tea. Nineteen real tea samples were analyzed using TXRF. The advantages of TXRF have been presented through the comparison of results with the wavelength-dispersive X-ray fluorescence spectrometry method.

Essential and toxic elements in seaweeds for human consumption

Essential elements (K, Ca, P, S, Cl, Mn, Fe, Cu, Zn, Ni, Br, and I) and nonessential or toxic elements (Al, Ti, Si, Rb, Sr, As, Cd, Sn, and Pb) were determined by energy-dispersive polarized x-ray fluorescence spectrometry in 14 seaweeds purchased in local specialty stores in Italy and consumed by humans. The differences in elements between the algae species reached up to 2-4 orders of magnitude. Lithothamnium calcareum showed the highest levels of Ca, Al, Si, Fe, and Ti. Palmaria palmata showed the highest concentrations of K, Rb, and Cl. The highest content of S was in Chondrus crispus. Laminaria digitata contained the highest concentrations of total As, Cd, Sn, Br, and I. The highest concentration of Zn was in Chlorella pyrenoidosa. Ulva lactuca displayed the highest levels of Cu, Ni, Mn, and Pb. Iodine levels ranged from 3.4 in Chlorella pyrenoidosa to 7316 mg/kg(dry) in Laminaria digitata. The nutrimental importance of essential elements was assessed using nutritional requirements. The results showed that the consumption of algae might serve as an important source of the essential elements. Health risk due to the toxic elements present in seaweed was estimated using risk estimators. Total As, Cd, and Pb concentrations ranged from <1 to 67.6, to 7.2 and to 6.7 mg/kg(dry) respectively; therefore, their contribution to total elemental intake does not appear to pose any threat to the consumers, but the concentrations of these elements should be controlled to protect the consumer against potential adverse health risks.

Potential Health Risk of Herbal Distillates and Decoctions Consumption in Shiraz, Iran

Concentration of 26 elements in 16 different herbal distillates and 5 herbal decoctions, were determined using inductively coupled plasma-mass spectrometry (ICP-MS). The elemental content of five raw herbal materials used for making decoctions and seven distilled and boiled residues were also evaluated by inductively coupled plasma optical emission spectrometry (ICP-OES). The results indicated that herbal products display a wide range of elemental concentrations. Compared with world health regulations, the concentrations of the elements in herbal distillates and decoctions did not exceed the recommended limits. The analysis of herbal extracts did not show a significant transfer of toxic elements during decoction preparation. Comparison of elemental content among fresh herbal material and herbal distillate and decoction of the same herb showed that, besides the elemental abundance of herbal organs, the ionic potential of elements also play an important role in elemental content of herbal products. Based on the results of the research, it seems that most health benefits attributed to herbal products (especially herbal distillates) are more related to their organic compounds rather than elemental composition. Calculated hazard quotient (HQ) and hazard index (HI) were used to evaluate the noncarcinogenic health risk from individual and combined metals via daily consumption of 100 ml of herbal distillates and 250 ml of herbal decoctions. Both HQs and HI through consumption of herbal distillates and herbal decoctions (except Valerian) were below 1. Apparently, daily consumption of herbal distillates and decoctions at the indicated doses poses no significant health risk to a normal adult.

Levels of major and trace elements in fennel (Foeniculum vulgari Mill.) fruits cultivated in Ethiopia

Background

Sweet fennel (Foeniculum vulgare Mill.) is one of the precious spices. Almost all parts of fennel plant are edible. The herb is used as carminative, digestive, diuretic, cosmetic and medicine.

Methods

A 0.5 g of the oven dried fennel fruit and soil samples were digested by wet-digestion method. The levels of selected elements (Ca, Mg, Fe, Mn, Cu, Cr, Co, Zn, Ni, Cd and Pb) were determined in sweet fennel fruit (Foeniculum vulgari Mill.) and soil from Addis Ababa (Central Ethiopia) and Gojjam (Northern West Ethiopia) by flame atomic absorption spectrometry (FAAS).

Results

The elemental concentrations (μg/g) in fennel fruit were: Ca (20,500–23,000), Mg (1,310–3,460), Fe (1,140–1,900), Mn (31–51), Cu (24–103), Cr (91–98), Co (26–71), Zn (37–45), Ni (19–24), and Cd (1.6–1.9) while in the soil were: Ca (1,440–1,780), Mg (1,260–3,310), Fe (26,900–28,000), Mn (1,460–1,980), Cu (51–101), Cr (127–141), Co (54–143), Zn (99–104), Ni (98–161), and Cd (1.7–2.9). Pb was below the method detection limit in both the fennel fruit and soil.

Conclusion

The Ethiopian fennel fruits are rich in Ca and Mg and other essential elements (Fe, Cu, Co and Zn) and can be used as good supplement for human being in particularly for children and pregnant women. The toxic element Cd is at trace level and Pb is not detected in the fennel fruit. Thus, Ethiopian fennel fruits are safe for human consumption.