Determination of essential elements in beverages, herbal infusions and dietary supplements using a new straightforward sequential approach based on flame atomic absorption spectrometry

Novel highly selective quinoline-based fluorescent chemosensors for quantitative analysis of Cu(II) ion in water and food

While copper (Cu2+) is a vital cofactor in numerous enzymatic processes, its homeostasis is critical. Selective sensors for Cu2+ in food matrices are paramount for ensuring adherence to safety regulations and dietary interaction studies. In this work, novel derivatives of 8-aminoquinoline (L1-L4) with extended π-conjugation and various N-substituents were synthesized and evaluated as fluorescent sensors for Cu2+. The 2-pyridinecarbonyl-substituted derivative L3 exhibited sharp fluorescence quenching selectively in the presence of Cu2+. This compound presents high selectivity for Cu2+ even in the presence of other metal ions. The L3-based fluorescent sensor provides a Cu2+ detection limit of 77 nM, surpassing many existing sensors. The quantifications of Cu2+ in water, food supplements, and wines using this sensor have demonstrated good agreement with those obtained using the standard ICP technique. Notably, L3 also facilitates Cu2+ detection in microliter sample volumes at subnanomole levels using paper-based sensors, opening doors for portable and cost-effective on-site testing.

A Comparative Study Between Conventional ICP-OES and the Innovative PLS Model-Assisted ICP-OES for the Assay of Trace Elements

BACKGROUND

Inductively coupled plasma is widely used for elemental analysis with the advantage of being eco-friendly since the discharge is free of contaminants.

OBJECTIVE

A rapid, novel method was developed for the quantitation of trace elements using inductively coupled plasma with optical emission spectrometry.This method has the advantage of simultaneous calibration compared to the conventional method.

METHOD

The assay was carried out for iron, copper, zinc, and molybdenum using the linear regression model partial least-squares.

RESULTS

The method was optimized and validated as per the International Conference on Harmonization guidelines, showing highly accurate and precise results. The linearity range was 0.25-4 ppm for all trace elements under investigation. The method was applied for the assay of the cited elements in non-chelated and amino acid chelated multi-mineral preparations in the Egyptian market with acceptable mean percent recovery.

CONCLUSIONS

In comparison with the official method by flame emission, statistical analysis showed no significant difference with Student's t-test and F-values.

HIGHLIGHTS

Inductively coupled plasma is superior as all of the elements can be measured simultaneously. The method was found to have a high degree of specificity and can be easily applied in routine elemental analysis in laboratories.

Investigation of twelve trace elements in herbal tea commercialized in Brazil

In this study twelve trace elements were investigated in herbal tea commercialized in Brazil. Boldo, Chamomile, Mate and Peppermint tea samples were acquired in Brazil local markets and both herbs and their infusions were evaluated. Trace elements were classified in two groups: poorly (Al, As, Ba, Cd, Cr, Fe, Pb and Se) and moderately (Cu, Mn, Ni and Zn) extractable. This patterned showed that even levels above threshold established by Brazilian and MERCOSUR regulations were observed in herbal tea (Cd and Pb in 89% and 78% of mate and peppermint tea samples, respectively), their infusions did not presented toxic levels. The estimative of exposure and dietary intake revealed important values for a daily consumption of a single cup of herbal infusion and an unique composition was also verified for herbal tea samples: although age and origin was unavailable, multivariate analysis classified the samples in four distinct groups.

Assessment of some heavy metal accumulation and nutritional quality of shellfish with reference to human health and cancer risk assessment: a seafood safety approach

This study was conducted to assess the proximate analysis (protein, carbohydrate, lipid, and moisture content) and concentration levels of metals (Zn, Cu, Cd, Pb, and Cr) in the muscles of selected shellfish (Portunus reticulatus, P. segnis, P. sanguinolentus, Scylla olivaceae, Penaeus monodon, and P. indicus) species. The concentration of metals showed significant difference (p > 0.05) among species. The detected concentrations of the analyzed heavy metals were below the daily intake and legal limits set by national and international standards. The THQs and CR index were calculated to evaluate the risk estimation of the metal contamination associated with the human health. The THQ values of all metals were below 1 in all species, indicated that there is no risk of adverse health effect, but the risk of elevated intakes of heavy metals adversely affecting food safety for the studied species. The CR index indicated that Cd and Pb caused the greatest cancer risk. The correlation and multivariate (principle component analysis) among metal concentration and nutritional quality were also evaluated. The carbohydrate and moisture showed the positive correlation (p > 0.05) with metals. The biochemical results of the present work clearly indicate that there was a significant difference in the muscles of shellfish. It was concluded that more effective controls should be focused on Cd and Pb to reduce pollution for quality and seafood safety concern.

Micro-sampling method based on high-resolution continuum source graphite furnace atomic absorption spectrometry for calcium determination in blood and mitochondrial suspensions

A micro-sampling and straightforward method based on high resolution continuum source atomic absorption spectrometry (HR-CS AAS) was developed to determine extracellular and intracellular Ca in samples of interest in clinical and biomedical analysis. Solid sampling platforms were used to introduce the micro-samples into the graphite furnace atomizer. The secondary absorption line for Ca, located at 239.856nm, was selected to carry out the measurements. Experimental parameters such as pyrolysis and atomization temperatures and the amount of sample introduced for the measurements were optimized. Calibration was performed using aqueous standards and the approach to measure at the wings of the absorption lines was employed for the expansion of the linear response range. The limit of detection was of 0.02mgL^-1 Ca (0.39ng Ca) and the upper limit of linear range was increased up to 8.0mgL^-1 Ca (160ng Ca). The proposed method was used to determine Ca in mitochondrial suspensions and whole blood samples with successful results. Adequate recoveries (within 91-107%) were obtained in the tests performed for validation purposes.