26 research outputs found
Biosorptive removal of Pb2+, Cd2+ and Zn2+ ions from water by agenaria vulgaris shell
Lagenaria vulgaris (LV) shell was used as a biosorbent for the removal of heavy metal ions, Pb2+, Cd2+ and Zn2+, from aqueous solutions. Experiments were carried out under batch conditions. The effects of contact time, initial pH, temperature and stirring speed on removal efficiency are presented. Sorption of the investigated metals was fast, reaching equilibrium after about 5 to 10 min, depending on the metal. Biosorption was highly pH-dependent, and the optimal pH for investigated metals was in the range of 4.5 to 6.0. The effects of temperature demonstrated that biosorption of the metals is a chemical process. SEM analysis revealed interesting morphological changes after acid refinement of the raw biosorbent and metal uptake that is related to the chemical nature of the biosorption process. EDX analysis of Lagenaria vulgaris biosorbent(LVB) before and after metal sorption revealed that the ion exchange mechanism was the principal sorption process. Fourier transform infrared spectroscopy (FTIR) analysis has shown that major functional groups (carboxyl and hydroxyl) on the biosorbent surface took part in the metal ion uptake process as active sites. The results obtained showed that Lagenaria vulgaris based biosorbent could be used as an effective and low-cost pre-treatment step for removal of toxic metals from wastewaters
The correlation of metal content in medicinal plants and their water extracts
The quality of some medicinal plants and their water extracts from South East Serbia is determined on the basis of metal content using atomic absorption spectrometry. The two methods were used for the preparation of water extracts, to examine the impact of the preparation on the content of metals in them. Content of investigated metals in both water extracts is markedly lower then in medicinal plants, but were higher in water extract prepared by method (I), with exception of lead content. The coefficients of extraction for the observed metal can be represented in the following order: Zn > Mn > Pb > Cu > Fe. Correlation coefficients between the metal concentration in the extract and total metal content in plant material vary in the range from 0.6369 to 0.9956. This indicates need the plants to be collected and grown in the unpolluted area and to examine the metal content. The content of heavy metals in the investigated medicinal plants and their water extracts is below the maximum allowable values, so they are safe to use
Content of Trace Metals in Medicinal Plants and their Extracts
The heavy metals (Fe, Cu, Zn and Mn) contents of selected plant species, grown in Southeast region of Serbia, that are traditionally used in alternative medicine were determined. Among the considered metals, iron content was the highest one and varied from 137.53 up to 423.32 mg/kg, while the contents of Cu, Zn and Mn were remarkably lower, and ranged from 8.91 to 62.20 mg/kg. In addition, an analysis of plants extracts showed a significant transfer of heavy metals during extraction procedure; therefore, the corresponding extraction coefficients reached values up to 88.8%. Those were especially high in the ethanol based extracts. Moreover, it is was established that such coefficients mostly depend on the solvent nature and also on the treated plant species. The obtained results impose that medicinal plants from Southeast region of Serbia due to rather low content of heavy metals are appropriate for preparation of teas and medicinal extracts
Design and photocatalytic ability of ordered mesoporous TiO2 thin films
Homogeneous and crack-free TiO2 films with templated mesoporosity were prepared by the dip coating technique using an evaporation-induced, self-assembly method. The synthesized mesoporous TiO2 films were characterized using SEM/TEM, BET and XRD techniques. Degradation reactions of methylene blue and crystal violet dyes were used to test the photocatalytic capability of mesoporous TiO2 films. The degradation kinetics of methylene blue and crystal violet were investigated over a broad range of initial concentrations of the organic dyes. The kinetic data were correlated with the specific surface area and thickness of mesoporous TiO2 films, as well as number of reaction cycles
A comparative study of n-hexane isomerization over solid acids catalysts: Sulfated and phosphated zirconia
Determination of Benzalkonium Chloride in Nasal Drops by High-Performance Liquid Chromatography
A high-performance liquid chromatography (HPLC) system was used in the reversed phase mode for the determination of benzalkonium chloride (BKC) in nosal drops. A Chromolit RP-18e, 100 x 4.6, (UM6077/035) column was used at 40 Ā°C. The mobile phase, optimized through an experimental design, was a 70:30 (v/v) mixture of 0.057M Na-heksansulphonate potassium, dihydrogen orthophosphate buffer (pH 2.9) and acetonitrile, pumped at a flow rate of 1.75 mL/min at maintaining column temperature at 40 Ā°C. Maximum UV detection was achieved at 215 nm. The method was validated in terms of selectivity, linearity, repeatability, precision and accuracy. The method was successfully applied for the determination of BKC in a pharmaceutical formulation of nasal drop solution without any interference from common excipients and drug substance. All the validation parameters were within the acceptance range, concordant to ICH guidelines
Phenolic Content, and Antioxidant and Antimicrobial Activities of Crataegus Oxyacantha L (Rosaceae) Fruit Extract from Southeast Serbia
Total phenolic and flavonoid contents of different extracts of Papaver rhoeas L. were examined. High contents of total phenolic compounds (9.73 -19.91 mg GAE/g of fresh petals) and total flavonoids (7.904 -11.45 mg QE/g of fresh petals) were determined. Red pigment present in the flowers of P. rhoeas L. originates from anthocyanins, which may act as natural antioxidants. Anthocyanins content in the investigated extracts is very unified and ranged from 4.72 to 5.193 mg of cyanidin-3-O-glukoside/g of fresh petals. The antioxidant activity of different extracts was tested using the spectrophotometric method by means of the ability of extracts to scavenge stable 1,1-Diphenyl-2-picrylhydrazyl (DPPH). All tested extracts exhibited strong scavenging activity against DPPH radicals, that is higher then 80%. Total phenolic and flavonoid contents may be related to the percentages of the scavenging activity of DPPH assay (estimated correlation coefficient are R 2 = 0.965 and 0.752, respectively). The ethanol extract of P. rhoeas L. showed antimicrobial activity against the yeast Candida albicans, and all tested bacteria except Bacillus subtilis. This paper suggests that the investigated extracts of plant P. rhoes L. could be potentially applied as an antioxidant and antimicrobial agents. Key words: Papaver rhoeas L., phenolic content, anthocyanins content, flavonoid content, antioxidant activity, antibacterial activity. INTRODUCTION Papaver rhoeas L. (Papaveraceae) is an annual herb indigenous to numerous regions in the world. In traditional medicine until synthetic drugs are developed, extracts of this plant have been used for the treatment of a wide range of diseases including inflammation, diarrhea, sleep disorders and, moreover, for cough, analgesia and also the reduction of withdrawal signs of the opioid addiction. It is also claimed that plant P. rhoeas exhibits sedative, narcotic, and emollient effects ( In the present paper, the evaluation of P. rhoeas L. from Southeast Serbia with respect to phenolic content and the antioxidant data of different extracts obtained from plant petals are reported. As it is stated earlier, numerous polyphenols are known to possess excellent antioxidant effects, especially in vitro, and the amount of total polyphenols present in a plant has been suggested to correlate with the antioxidant activity. Therefore, this work represents the first report on phenolic content and related antioxidant activity of the extracts of P. rhoeas L. from Southeast Serbia. Antimicrobial activity of ethanol extract of P. rhoeas was investigated, too. EXPERIMENTAL Plant material The plant was collected at bloom stage in few villages from the South-eastern Cape Province of Serbia in July, 2009. The plant was firstly identified by its vernacular name and later validated by voucher number of the deposited herbarium specimens at the Department of Botany (University of Novi Sad, Serbia). Preparation of plant extracts The fresh petals of P. rhoeas L. were milled by an appropriate blender. Three samples (each weighed 2.0 g) were separated from the previously homogenized plant material, and extracted with the desired volumes (30, 20 and 20 ml, respectively) of the chosen solvents (methanol, ethanol, methanol-water mixture, ethanol-water mixture and water) three times in the further course. Samples were mixed in an ultrasound bath during the extraction procedure. Such obtained extracts were filtered using the Buchner funnel and Whatman No. 1 filter paper. Solid residues were rinsed for several times in order to gain transparent extracts. Finally, the obtained plant extracts were collected in graduated flask of the same volume of 100 ml. Chemicals and reagents 1,1-Diphenyl-2-picrylhydrazyl (DPPH), quercetin and AlCl3 were purchased from Sigma Chemical Co. (St. Louis, MO, USA). FolinCiocalteu's phenol reagent and sodium carbonate were purchased from Merck Chemical Suppliers (Darmstadt, Germany). Sodium chlorate buffer (pH 1.0) and acetate buffer (pH 4.5) were purchased from the same producer. The other used chemicals including solvents were of analytical grade. Determination of the total phenolics Total phenolic contents in the extracts were determined by the modified Folin-Ciocalteu method Determination of the total monomeric anthocyanins The total monomeric anthocyanin content in the plant extracts was determined using the pH-differential method previously described by (1) Content of the monomeric antocyanin pigment (MAP) was calculated by Equation 2