Forsythia represents a group of plants originating mainly from China and Japan, but one species is endemic and grows in the Balkans (Balkan forsythia, Forsythia europaea Degen & Bald.). Our previous ...studies on polyphenols in investigated extracts of Balkan forsythia showed that this plant is a good source of polyphenols. Analysis of the various extracts of Balkan forsythia (Forsythia europaea Degen & Bald.) by the application of ICP-OES method showed that they are rich in different macro and microelements. The abundance order of macroelements is K>Ca>P>Mg>Na in all extracts. Among the transition metals iron, manganese, zinc and copper are particularly important, and the order of abundance is Zn>Fe>Cu>Mn. Heavy metals which are the most frequent contaminants of food are lead, cadmium and arsenic, and the determination of their contents is of special importance on the safe use of plant species. The determination shows that aqueous extracts contain the highest quantity of elements, which is especially important. The contents of toxic elements are significantly lower than the permitted values. Statistical methods (Principal Component Analysis (PCA) and Agglomerative Hierarchical Clustering (AHC)) are useful tools for the grouping of samples and determining relations between investigated elements. This analysis shows that when higher quantities of Cr and Ba are present, the lower quantities of V are present, and vice versa. Based on our studies on polyphenols and minerals, we can expect the anti-inflammatory effects of extracts of Balkan forsythia.
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.
The results of developed kinetic-spectrophotometric method for serum urea determination by modified colorimetric Berthelot procedure were presented in this paper. To obtain high sensitivity, all ...reaction rates were monitored spectrophotometrically by measuring the change of absorbance with time at 700 nm. A differential variant of the tangent method was used for the processing of the kinetic data based on linear dependence of absorbance on time. The method is valid over the 0.25–2.50 µg cm
−3
urea concentration interval with RSD range 8.33–2.02%. The limit of detection was calculated as 0.09 µg cm
−3
. The interference effects of some metal ions, anions, antibiotics, and other molecules were investigated to access the method selectivity. The method was successfully applied for the determination of urea in human quality control blood serum.
A simple, rapid, sensitive and selective kinetic spectrophotometric method for determination of Fe(III) traces was elaborated in this paper. It is based on the catalytic effect of Fe(III) ions on ...oxidation of potassium salt of disulphonated hydroquinone (K2S2Hy) by hydrogen peroxide in acidic media, at a constant ionic strength. At the working temperature of 20?C and the wavelength of 450.0 nm, optimal conditions for determination of iron were found so that iron (III) can be determined by the proposed method in the concentration range of 1.87 to 18.7 ng cm-3. Corresponding RSD values were determined to be in the range 4.22 to 10.33 %. The limit of detection (LOD) calculated in two ways was found to be 1.07 ng cm-3 i.e. 1.11 ng cm-3 Fe(III). In order to assess the selectivity of the method effects of different ions on the reaction rate were also determined. It was found that presence of oxalates and citrates in the w/w ratio to Fe(III) 1:1 under selected experimental conditions interferes with determination of iron. Then the method was applied for determination of Fe(III) traces in white radish juice. The results agreed well with those obtained by atomic absorption spectrometry.
nema
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.
A kinetic spectrophotometric method for determining residues of insecticide diflubenzuron 1(4-chlorphenyl)-3-(2,6-diflubenzoyl)urea (DFB) has been developed and validated. Kinetic method was based on ...the inhibitory effect of DFB on the oxidation reaction of sulfanilic acid (SA) by hydrogen peroxide in the presence of Co2+ ions in a phosphate buffer, which was monitored at 370 nm. DFB can be measured in the concentration interval 0.102 ? 3.40 ?g mL-1 and 3.40 ? 23.80 ?g mL-1. The detection and quantification limits of the method were calculated according to the 3? criteria and found to be 0.077 ?g mL-1 and 0.254 ?g Ml-1, respectively. The relative standard deviations for five replicate determinations of 0.102, 1.70 and 3.40 ?g mL-1 DFB were 2.08, 1.22 and 1.21 %, respectively, for the first concentration interval, and the recovery percentage values were from 94.12 to 97.35 %. HPLC method was used as a parallel method to verify results of the kinetic method. The kinetic method was successfully applied to determine diflubenzuron concentrations in spiked water and baby food samples after solid phase extraction of the samples. The F and t values at 95% confidence level are lower than the theoretical ones, confirming agreement of the developed and the HPLC method.
The aim of this paper was the optimization and validation of an inductively coupled atomic emission method (ICP-AES) for macro- and trace element determination in berry samples. To optimize the ...atomization and ionization processes in an inductively coupled plasma source, the Mg(
ii
) 280.270 nm/Mg(
i
) 285.213 nm (Mg(
ii
)/Mg(
i
)) line intensity ratio was used for both viewing (axial and radial) modes. In particular, the effects of the power and the carrier gas flow rate are described. The power was varied from 750 kW to 1350 kW in intervals of 100 kW. The nebulizer argon flow rate was increased from 0.5 mL min
−1
to 1.5 mL min
−1
in intervals of 0.5 mL min
−1
. The Mg(
ii
)/Mg(
i
) ratio at an applied power of 1150 W and a nebulizer gas flow rate of 0.5 L min
−1
for axially and radially viewed configurations was 10.57 and 12.06, respectively. The validation process of the developed method involved precision, accuracy, linearity of the calibration curve, limit of detection (LOD) and limit of quantification (LOQ). Accurate results were found for a certified reference material. In analyzed samples, 20 elements were studied and 18 (Ca, K, Mg, P, Na, Al, B, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Si, and Zn) elements were determined quantitatively. Potassium is the metal with major content, followed by Ca, P, Mg, Na and other micro-elements, such as Mn, Fe, Cu, Zn and Si. According to the toxic element contents, the investigated samples are considered safe for human consumption. Generally, berry samples are significant sources of elements that are essential to human health and diet.
Evaluation of an ICP-AES method that considers plasma robustness and matrix effects for the determination of metals in berry fruits.
•The contents of trace elements in baby purees and juices were investigated.•The lead concentration was detected in the range from nd to 0.21 µg/kg.•ADDs of Pb for infants and toddlers were in ...accordance with EFSA estimated ranges.•All HIs for infants and toddlers were below or slightly above the acceptable limit.•Studied product types were divided into three groups applying statistical analyses.
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.
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