Accurate Determination of Total Antimony Using ICP-MS and Optimization Its Extraction Efficiency From Reference and Soil Samples

Two independent digestion techniques (microwave acid digestion with HF and HCl, HNO3 and Na2O2 sintering, respectively) were applied to determine the total Sb concentration in a real soil sample and in reference materials: Icelandic Basalt (BIR-1), Cody Shale (SCo-1) and (Soil-7). ICP-MS was used to determine total antimony concentrations in the digested and the extracted solutions using external calibration and isotope dilution technique. The recoveries of Sb using HF in the acids digestion mixture in closed-vessels microwave digestion system were excellent and the concentrations are in very good agreement with certified or reported concentrations of reference materials. Using closed-vessels combined with microwave heating systems probably prevents the loss of volatile Sb compounds. The use of hydrogen fluoride with other strong acid can help dissociating insoluble antimony silicates. Different extraction reagents were tested for their ability to extract antimony using an ultrasonic bath namely: EDTA disodium salt, potassium hydroxide, citric acid monohydrate, pyridine-2,6-dicarboxylic acid, ammonium acetate, ammonium oxalate, ammonium thiocyanate, ammonium persulphate and di-ammonium hydrogen citrate. A 500 mmol L-1 solution of citric acid pH 1.08 proved to be the most efficient extractant. Optimization of the extraction conditions were investigated by studying the effect of pH, concentration, temperature, time of extraction, the ratio of sample mass to the volume of extractant and the number of consecutive extractions. As a result three consecutive extractions for a total time of 45 min at 80 ˚C was the most efficient condition for Sb extraction. Using these extraction conditions 61%, 3.7% RSD and 42%, 2.2% RSD (n=6) of the total antimony in the real soil and Soil-7 samples, respectively could be extracted

Spectrophotometric determination of fluoride in drinking water using aluminium complexes of triphenylmethane dyes

A sensitive spectrophotometric determination of fluoride in drinking water has been developed using aluminium complexes of triphenylmethane dyes (chrome azurol B and malachite green) as spectrophotometric reagents. The method allowed a reliable determination of fluoride in the range of 0.5–4.0 mg·l-1 for chrome azurol B and 0.0–2.0 mg·l-1 for malachite green. The molar absorptivity for the complexes of chrome azurol B at 582 nm and malachite green at 622 nm is 1.44 × 104 and 2.56 × 104 l·mol-1·cm-1, respectively. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.5 mg·l-1 fluoride for the method using chrome azurol B were found to be 0.125 ± 0.003 µg·ml-1, 0.2 mg·l-1, 0.5 mg·l-1, and 97.1 ± 4.2, respectively, and for malachite green were 0.143 ± 0.002 µg·ml-1, 0.1 mg·l-1, 0.3 mg·l-1, and 97.9 ± 4.1, respectively

Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively

التحلل الضوئي للميثاميدوفوس (مبيد حشري) في الماء باستخدام اكسيد التيتانيوم النانوي البلوري المعدل بالصبغ المدعوم على أسطح الكربون المنشط

Anatase TiO2 surfaces have been treated with 2, 4, 6-triphenylpyrylium hydrogen sulfate (TPPHS) or tripyridylporhpyrinatomanganese(II) (MnP) dyes to yield the modified TiO2/ dye surfaces. The modified TiO2/dye surface was then supported onto activated carbon (AC) surfaces to yield a new class of catalytic system AC/TiO2/dye. The catalytic activities of naked TiO2, dye solution, TiO2/dye, and AC/TiO2/dye systems were examined in photo-degradation of Methamidophos (insecticide) in water, using both UV and visible light. All examined systems showed catalytic activity when used either in the UV or the visible regions, but the AC/TiO2/ dye showed the highest activity. The dye role, in enhancing activity of modified surfaces in UV degradation of the examined contaminants, is understandable by a charge-transfer catalytic effect. AC role can be explained by its ability to adsorb contaminant molecules and bringing them closer to catalytic sites. There was no significant temperature effect on catalyst efficiency in Methamidophos photo-degradation. Oxygen is essential for semiconductor photocatalytic degradation of Methamidophos, but higher oxygen concentrations lead to a downturn of the reaction rate

تخليق وتقييم إمكانات مضادات الليباز والالتحام الجزيئي لـلمركب الجديد N \u27- (2-Hydroxy-5-nitrobenzylidene) naphthalene-2-sulfonohydrazide

N’-(2-Hydroxy-5-nitrobenzylidene) naphthalene-2-sulfonohydrazide (SB) was prepared by condensation reaction, of naphthalene-2-sulfonylchloride with 2-Hydroxy-5-nitrobenzaldehyde. The Schiff base product (SB) was isolated, purified and then spectrally characterized via UV-Vis, FT-IR, 1H and 13C NMR analysis, where strong evidences confirmed the formation of the desired product. Pancreatic porcine lipase inhibition of the Schiff base product was evaluated and compared with the reference “Orlistat”. The product was an active as a lipase enzyme inhibitor with IC50 42.65±0.97 mcg/ml. The molecular docking of the compound with porcine pancreatic lipase was investigating, the results of theoretical docking explained the experimental one since several hydrogen bonds between the Schiff base compound and amino acids in lipase were detected. Antimicrobial activity of SB product was also evaluated in vitro against several types of bacteria such as: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia and MRSA by Minimum Inhibitory Concentration (MIC) test using tetracycline (TE) as a standard antibiotic. Results showed a bacteriostatic effect of this compound against bacteria such as MRSA, P. aeruginosa and K. pneumoniae

Using Nonconventional Water in Irrigation of Olive Trees and Its Effect on Olive Oil Properties

The response of olive orchard with same age and type to irrigation with treated municipal wastewater and freshwater was investigated in three years. Physical and chemical properties of the treated municipal wastewater reuse in agriculture (the effluent) produced by the Sheikh Ejleen wastewater treatment plant in Gaza Strip, freshwater, soil, and olive oil were determined and compared with Palestinian and international standards. The biological oxygen demand (BOD) of Sheikh Ejleen effluent is 60 mg∙l−1, which indicates low quality effluent. The results indicate that most of olive oil quality parameters— including heavy metals and trace elements for both fruits irrigated with treated wastewater or irrigated with freshwater—fall within the acceptable standard limit values. Moreover, soil analysis shows that organic content and cation exchange capacity were improved in soil irrigated with treated wastewater in comparison with that irrigated with freshwater. The results also show that there is no trace elements or heavy metals accumulation in soil.The authors thank Eng. Haneen N. Al-Sbihi and Eng. Yousra A. Abu-Sharekh for the help in samples collection and data analysis during their graduation project in the Environmental Engineering Department—Islamic University of Gaza. The project Water and Livelihood Initiatives (WLI)-ICARDA is highly acknowledged for supporting this work to be published

Synthesis, NMR, DFT, GRD, MEP, FMO’s analysis and comparison of E and Z-isomer of N'-((4-bromothiophen-2-yl)methylene)naphthalene-2-sulfonohydrazide

A novel Schiff base N'-((4-bromothiophen-2-yl) methylene) naphthalene-2-sulfonohydrazide ligand was prepared by condensation of equivalents amount of naphthalene -2-sulfonylhydrazide with 4-bromo-2-thiophenecarboxaldehyde. The newly synthesized ligand was isolated in excellent yield. CHN-EA, UV-Vis., GC/MS, FT-IR, 1H and 13C NMR were used to determine the structure of the desired ligand. Density functional theory DFT B3LYP/6-311G(d,p) was performed to optimize the E and Z- structural isomerization process. Several quantum calculation parameters like optimized bond length, angle ant torsional angels in addition to HOMO/LUMO, GRD, and MEP map, for both E and Z isomers have been calculated and compared under the same level of theory

In vitro assessments of cytotoxic and cytostatic effect of two [Cu(dien)(N-N)]Br2 complexes on L6, HCT, PC3 and HepG2 cancer cells

Two new Cu(II) complexes of type [Cu(dien)(N-N)] Br2 (dien is diethlylenetriamine, C1 complex with N-N = diethlylenetriamine and C2 complex with N-N = propyl-1,3-diamine) were made valuable  and in vitro screened for both cytostatic and cytotoxic activities against four cell lines: colon cancer (HCT), liver cancer (HepG2), prostate cancer (PC3) and as control cell (L6) human muscle cell was used via MTT test. The results reflected these complexes as a promising activity antiprolifrative agent against the used cell lines indicating that C1 and C2 complexes have a high anticancer activity at non-toxic concentrations

Synthesis, XRD, DFT-optimization, MEP and Hirshfeld surface analysis of di-μ-Chloro-bis[chloro(1,10-phenanthroline)Cd(II) dimer

Cadmium(II) dimer complex of type  [Cd2(phen)2Cl4] was made available in a high yield, the structure of the dimer was solved by XRD then optimized via density functional theory (DFT) and  Hirschfield computed methods. The structure parameters like: angles and bonds lengths were compared to their DFT-relatives, Hirschfield surface analysis (HAS), molecular electrostatic potential (MEP) and Mulliken charge populations were also matched to the XRD-packing collected result. The dimer was crystallized in the Triclinic/P-1 system with Z = 4. The two Cd(II) centers in the dimer found to be with a distorted square-pyramidal geometry. Crystallographic data for desired dimer was deposited to the Cambridge Crystallographic Center under CCDC No. 1911235