Elemental composition of edible nuts: fast optimization and validation procedure of an ICP-OES method.

BACKGROUND: An inductively coupled plasma-optical emission spectrometry method for the speedy simultaneous detection of 19 elements in edible nuts (walnuts: Juglans nigra; almonds: Prunus dulcis; hazelnuts: Corylus avellana; Brazil nuts: Bertholletia excelsa; cashews: Anacardium occidentalle; pistachios: Pistacia vera; and peanuts: Arachis hypogaea) available on the Serbian markets, was optimized and validated through the selection of instrumental parameters and analytical lines free from spectral interference and with the lowest matrix effects. RESULTS: The analysed macro-elements were present in the following descending order: Na > Mg > Ca > K. Of all the trace elements, the tested samples showed the highest content of Fe. The micro-element Se was detected in all the samples of nuts. The toxic elements As, Cd and Pb were either not detected or the contents were below the limit of detection. One-way analysis of variance, Student's t-test, Tukey's HSD post hoc test and hierarchical agglomerative cluster analysis were applied in the statistical analysis of the results. CONCLUSION: Based on the detected content of analysed elements it can be concluded that nuts may be a good additional source of minerals as micronutrients.

Statistical characteristics of selected elements in vegetables from Kosovo.

Zinc, copper, iron, chromium and cobalt are essential elements for human health, showing toxicity only in high concentrations, while lead and cadmium are extremely toxic even as traces. Therefore, it is important to monitor the contents of toxic metals in vegetables. Large number of vegetables is grown and used in nutrition, in Kosovo. The concentrations of selected elements in vegetables (radish, onion, garlic and spinach) from Kosovo were determined using ICP-OES method. Oral intake of metals and health risk index were calculated. Statistical analysis indicated numerous positive correlations between concentrations of selected elements in vegetables. As a result of principal component analysis, 15 new variables were obtained which were characterized by eigenvalues. The sequence of health quotients for the heavy metals followed the decreasing order Zn = Mn > Pb > Cu > Ni > Fe > Cd > Co > Cr. The health quotients for all investigated heavy metals were below 1 (one), which is considered safe. The vegetables from Kosovo are mainly safe for use in everyday diet.

A simple method for the ampicillin determination in pharmaceuticals and human urine.

The new kinetically-based spectrophotometric method for the determination of microquantities of ampicillin is proposed in the present paper. Ampicillin degradation in strong alkaline medium was applied for the method development. The reaction rate was monitored at 265 nm. A differential variation of the tangent method was used to process the kinetic data. The method is valid over the 3.49-55.84 µg/mL ampicillin concentration interval with relative standard deviation (RSD) range 7.79-3.20%. The calculated detection limit was determined at 2.58 µg/mL based on the 3.3S0 criterion. The interference effects of some metal ions, anions, amino acids and other molecules were investigated in order to assess the method selectivity. The method was successfully applied to determining the content of ampicillin in commercial pharmaceutical preparations and human urine. The obtained results were in good correlation with the HPLC method results. The newly developed method is simple, inexpensive and efficient for the analysis of a large number of samples at room temperature in a short time.

Determination of ibuprofen in combined dosage forms and cream by direct UV spectrophotometry after solid-phase extraction.

Solid-phase extraction method followed by direct UV spectrophotometry at 264 nm was developed and applied for the selective ibuprofen determination in two-component formulation of ibuprofen and pseudoephedrine-HCl, combined powder which contains ibuprofen in the form of salt with L-arginine and 10% ibuprofen cream. Procedures for ibuprofen determination in complex pharmaceutical preparations by direct UV spectrophotometry lack selectivity because of interferences of other active substances and fat components. A limited number of spectrophotometric methods applicable to these samples are based on derivative (first and second-order) UV spectroscopy. Common HPLC procedures are more selective but more expensive and for creams also require some type of extraction because the large amount of oily excipients would clog up the column. The proposed solid-phase extraction method proved to be suitable for analysis of ibuprofen in combined tablets, powders and creams by direct UV spectrophotometry. Also the method provides an effective clean-up of the cream and allows ibuprofen determination by HPLC analysis. For the extraction three different commercial sorbents were tested: anion exchange Oasis MAX, hydrophilic-lipophilic balanced Oasis HLB and reverse-phase Chromabond C18ec. The optimization of the SPE method was first done on standard ibuprofen solutions and then the suitability of the method was checked on solutions of commercial pharmaceutical samples. The method yields good results for all three types of commercial preparations on the anion-exchange Oasis MAX cartridges, with recoveries of 90-100.2%. The interferences in UV analysis were not registered and good precision (RSD < 6%) was obtained. The present method has been verified as accurate as the reference HPLC with the great advantage of less expensive instrumentation. For this reason, the method would be suitable for a routine and rapid drug quality control.

Trace element content in commercial complementary food formulated for infants and toddlers: Health risk assessment.

The study aimed to analyze trace elements content in baby purees and fruit juices and to evaluate the health risk of young children. The average daily dose, hazard quotient, hazard index and total diet hazard quotient were calculated to assess the potential health risk on per capita and consumers only groups of infants and toddlers. There was no significant health risk for studied groups regarding the intake of trace elements via purees and juices consumption. Health risk for lead was not estimated since the oral reference dose for this metal was not yet established and PTWI value was withdrawn. The average daily dose of lead for infants (0.32 - 0.46 µg/kg bw/day) and toddlers (2.01 - 2.29 µg/kg bw/day) were in accordance with the daily lead exposure intervals estimated by EFSA. Applying statistical analysis, the products were classified into three groups according to the content of trace elements.

The Evaluation of ICP OES for the Determination of Potentially Toxic Elements in Lipsticks: Health Risk Assessment.

This study aimed to optimize and validate the inductively coupled plasma optical emission spectrometric method (ICP OES) for the simultaneous determination of eleven potentially toxic elements (Al, Cd, Cr, Co, Cu, Ni, Pb, Fe, Sb, Mn, and Zn) in lipstick samples. The method was evaluated by applying the standard addition method. The recoveries for all elements in lipsticks were between 90% and 110%, except for Cd and Pb they were <90% and >110%, respectively. The health risk assessment was determined by calculating the average daily intake (ADD), hazard quotient (HQ), and hazard index (HI). The highest mean value for ADD was for Fe (4.8×10-1 mg kg-1 day-1), and the lowest was for Co (9.3×10-6 mg kg-1 day-1). There was no significant toxic health risk for any of the elements (HQ < 1), except for Fe (HQ < 3) which indicates a potential health risk. Based on PCA, all potentially toxic elements have been classified in the three groups. The first group includes Fe, the second includes Al, and all other elements belong to the third group. The cluster analysis of the elements provided the identical grouping that was obtained on the basis of PCA. Two separate clusters were obtained when cluster analysis was applied to the analyzed samples. The first cluster contained the only sample that was brown. The second cluster was divided into two sub-clusters. The first sub-cluster included the samples belonging to category I regarding the price, while the second sub-cluster included the samples belonging to category II and III regarding the price.

Phenolic profiles and metal ions analyses of pulp and peel of fruits and seeds of quince (Cydonia oblonga Mill.).

Six hydroxycinnamic acids were identified and determined quantitatively in methanol and acetone extracts from quince peel and pulp, namely 3-O-caffeoylquinic acid (3-CQA), 4-p-coumaroylquinic acid (HC1), 4-O-caffeoylquinic acid (4-CQA), 5-O-caffeoylquinic acid (5-CQA), derivative of p-coumaroylquinic acid (HC2) and 3,5-dicaffeoylquinic acid (3,5-diCQA). The most abundant hydroxycinnamic acid was 5-CQA (neochlorogenic acid) with 259.12-481.4mg/kgf.w. in peel and 97.33-217.36mg/kg in quince pulp. Six flavonols were determined in the extracts from quince, quercetin-3-galactoside (Q-Ga), quercetin-3-rutinoside (Q-Ru), quercetin-3-glucoside (Q-Glu), kaempferol-3-rutinoside (K-Ru), kaempferol-3-glucoside (K-Glu) and derivative of quercetin produced in the reaction between quercetin-glucoside and p-coumaric acid (Q-Glu-p-CouA). Elemental analysis of quince seeds has not been performed previously. Also, using principal component and cluster analyses, we determined a strong negative relationship between total phenols and flavonoids, and Ni and Pb, specifically higher concentrations of these compounds were associated with lower concentrations of these metals.

Determination of streptomycin in a pharmaceutical sample based on its degradation by hydrogen peroxide in the presence of copper(II).

The kinetics of streptomycin degradation by hydrogen peroxide at pH 7.4 was investigated. The reaction was catalyzed by traces of Cu(II) ions, and it was followed spectrophotometrically at 322 nm by applying the initial-rate method. The kinetic parameters of the reaction are reported, and a rate equation is suggested. From the dependence of the relative rate constants on the temperature, the activation energy was calculated to be 57.5 kJ/mol. Based on this reaction, a kinetic method for streptomycin determination is proposed. The calibration graph is linear in the ranges 1.94 - 15.48 microg/cm(3) and 0.15 - 1.94 microg/cm(3). The influence of foreign ions and molecules on the accuracy of the determinations was investigated. The proposed kinetic method has high selectivity and good sensitivity, and enabled to determine streptomycin in pharmaceutical samples.

Exploitation of the antioxidant potential of Geranium macrorrhizum (Geraniaceae): hepatoprotective and antimicrobial activities.

In this study we evaluated in vitro (radical scavenging) and in vivo (hepatoprotective effect) antioxidant activities and antimicrobial properties of the extracts of the above- and underground parts of Geranium macrorrhizum L. (Geraniaceae), an ethnopharmacologically renowned plant species. The antioxidant activity and total phenol and flavonoid contents of four different solvent extracts were evaluated by seven different methods. The methanol extracts, administered i.p. to rats (120-480 mg/kg), were evaluated for hepatoprotective activity in a CCl4-induced hepatotoxicity model. The same extracts were tested for antimicrobial activity against seven bacterial and two fungal species. The administered methanol extracts with the highest antioxidant potential showed a significant dose-dependent hepatoprotective action against CCl4-induced liver damage in both decreasing the levels of liver transaminases and bilirubin and in reducing the extent of morphological malformations of the liver. The leaf methanol extract displayed a very strong antibacterial activity, especially against Staphylococcus aureus, with low minimal inhibitory and bactericidal concentrations. These results justify the frequent use of this plant species in folk medicine. Besides the known astringent effect, one can expect that the observed antimicrobial activity against several human pathogens contributes to the wound healing properties of this plant.

Heavy metal content in different types of smoked meat in Serbia.

Concentrations of Fe, Cu, Ni, Cr, Pb, Mn, Zn and Cd in pork, beef, turkey and chicken samples were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The mean concentration ranges in milligrams per 100 g of the studied metals in all samples were 0.6924-1.2154 for Fe, 0.6492-0.9831 for Cu, 0.0012-0.0027 for Pb, 0.041-0.0510 for Ni, 0.1186-0.1481 for Mn, 0.7257-5.2726 for Zn and 0.0042-0.0050 for Cd. The levels of analysed elements were in accordance with European standards for all metals except for manganese in all samples and for nickel in a certain number of samples. Zn level in beef was significantly higher compared to other samples, and Pb and Cd were found in concentrations well below the recommended daily intake.

Determination of diclofenac sodium in commercial pharmaceutical formulations and human control serum using a kinetic-spectrophotometric method.

A kinetic method for the determination of micro quantities of diclofenac sodium (DS) is described in this paper. The method is based on a ligand-exchange reaction. The reaction was followed spectrophotometrically by monitoring the rate of appearance of the cobalt diclofenac complex at 376 nm. The optimum operating conditions regarding reagent concentrations and temperature were established. The optimized conditions yielded a theoretical detection limit of 1.29 microg ml(-1) based on the 3S(b) criterion. The interference effects of certain drugs, foreign ions and amino acids upon the reaction rate were studied in order to assess the selectivity of the method. The developed procedure was successfully applied to the rapid determination of diclofenac sodium in commercial pharmaceutical preparations and human control serum. The unique features of this procedure are that determination can be carried out at room temperature and the analysis time is short. The newly developed method is simple, inexpensive, and efficient for use in the analysis of a large number of samples.