The consumption of dietary supplements is widely spread and on the rise. These dietary supplements are generally used without prescriptions, proper counseling or any awareness of their health risk. The current study aimed at analyzing the metals in 33 samples of imported dietary supplements highly consumed by the Lebanese population, using 3 different techniques, to ensure the safety and increase the awareness of the citizen to benefit from these dietary supplements. Some samples had levels of metals above their maximum allowable levels (Fe: 24%, Zn: 33%, Mn: 27%, Se: 15%, Mo: 12% of samples), but did not pose any health risk because they were below permitted daily exposure limit and recommended daily allowance except for Fe in 6% of the samples. On the other hand, 34% of the samples had Cu levels above allowable limit where 18% of them were above their permitted daily exposure and recommended daily allowance. In contrast, all samples had concentration of Cr, Hg, and Pb below allowable limits and daily exposure. Whereas, 30% of analyzed samples had levels of Cd above allowable levels, and were statistically correlated with Ca, and Zn essential minerals. Similarly 62% of the samples had levels of As above allowable limits and As levels were associated with Fe and Mn essential minerals. Dietary supplements consumed as essential nutrients for their Ca, Zn, Fe and Mn content should be monitored for toxic metal levels due to their natural geochemical association with these essential metals to provide citizens the safe allowable amounts.

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Evaluation of heavy metals content in dietary supplements in Lebanon

Information on the concentration of major, minor and trace elements in fruit juices is very important because the popularity of these beverages and the rate of their consumption have rapidly increased in the past 20 years. For the overwhelming majority of cases, the elemental analysis of fruit juices is carried out using spectrochemical analytical methods, which normally require samples of fruit juices to be prepared by decomposing their organic matrix and releasing elements in a form suitable for measurement. This review covers different aspects of the elemental analysis of fruit juices and the societal implications related to the presence of various elements in these beverages. We review in detail sample-preparation procedures executed before the elemental analysis together with calibration strategies used, and quality assurance and quality control of results.

Developments and strategies in the spectrochemical elemental analysis of fruit juices

Determination of phosphorus in food samples by X-ray fluorescence spectrometry and standard spectrophotometric method

Thisreport describes analytical techniques for major and trace elements in silicate rocks by X-ray fluorescence (XRF) spectrometry. The analyzed elements are SiOz, Ti02, A1203, total Fe203, MnO, MgO, CaO, Na20, K20, P2Os, Sc, V, Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Nd and Pb. All of these elements were determined on a single glass bead made from mixtures of 1 g of sample powder, 5 g of Li2B407 flux and about 50 mg of Lil releasing agent. A series of synthetic standard samples were prepared from pure chemical reagents to calibrate an XRF spectrometer. Matrix and line overlap corrections using a fundamental parameter approach yields reliable calibration lines with wide optimal ranges of composition. Analytical results of GSJ geochemical reference samples are in good agreement with their recommended values and exhibit sufficient precision and sensitivity for both major and trace elements.

Jing-Song Liu

Papers

X-Ray fluorescence analysis of trace elements in fruit juice

Quadratic polynomial technique for absorption correction in X-ray fluorescence spectrometry using continuous scattered background