Simultaneous Determination of Deltamethrin and Permethrin in Water Samples Using Homogeneous Liquid–Liquid Microextraction via Flotation Assistance and GC-FID

A new method was developed for the simultaneous determination of deltamethrin and permethrin in water samples with homogeneous liquid–liquid microextraction via flotation assistance and gas chromatography–flame ionization detection. A special extraction cell was designed to facilitate collection of the low density solvent extracts. The sample solution was added into the extraction cell, which contained an appropriate mixture of n-hexane (as an extraction solvent) and acetone (as a homogeneous solvent). Air flotation allowed the extraction solvent to be collected from the top of the solution. Under the optimum conditions, good linearity was observed in the range of 1.0–200 μg L^?1 with a correlation coefficient (r ²) greater than 0.9980 for both of the analytes. The limits of detection were 0.2 and 0.3 μg L^?1 for deltamethrin and permethrin, respectively (S/N = 3). The developed method was successfully applied to determine the two pesticides in three different water samples.     

H_3PW_(12)O_(40)催化水相介质中苯并恶嗪和喹唑啉合成（英文）

A heteropolyacid efficiently catalyzed the cyclocondensation reaction of 2‐aminobenzamide and salicylamide with aldehydes and ketones to afford good yields of benzoxazine and quinazoline ring systems in an aqueous medium. The method gives clean reactions, has simple workup procedure, and uses environment friendly conditions.     

Efficient Synthesis of Symmetrical Bisamides from Aldehydes and Amides Catalyzed by Silica-Bonded S-Sulfonic Acid Nanoparticles

Silica-bonded S-sulfonic acid nanoparticles (SBSSANPs) were easily synthesized from silica nanoparticles and showed to be an efficient catalyst in the synthesis the symmetrical N,N′-alkylidene bisamides. Reaction of aldehydes and amides in the presence of the catalyst afforded the corresponding bisamides in good to excellent yields. The extensive range of substrates suggests general applicability of the method. Reusability of the catalyst, simple workup procedure, and short reaction times are other advantages of this protocol.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications ^® to view the free supplemental file.     

Formation of uniform self-assembly monolayers by choosing the right solvent: OTS on silicon wafer, a case study

The main purpose of this research is to show the effects of solvent nature, partial charge distribution and polarity index, on the preparation of uniform silane self-assembly monolayers. Octadecyltrichlorosilane (OTS) on silicon wafers was chosen as a case study. Contrary to what was thought before, dipole moment data are not enough and one needs accompanying data on partial charge distribution and polarity index to predict the best solvent for a uniform self-assembled monolayer (SAM). Results can be applied to other monolayer-solvent systems.     

The Antifungal Activity of <Emphasis Type="Italic">Sarcococca saligna</Emphasis> Ethanol Extract and its Combination Effect with Fluconazole against Different Resistant Aspergillus Species

Microbial resistance is a major drawback in chemotherapy of microbial or fungal infection disease. In this study, the antifungal activity of ethanol extract of a selected plant (Sarcococca saligna) has been investigated against clinical isolates of Aspergillus niger, Aspergillus treus, Aspergillus flavus, and Aspergillus fumigatus. Also, the enhancement of the antifungal activity of fluconazole by this extract was further evaluated against mentioned test strains. Conventional disk diffusion method was used to assay the antifungal activity of S. saligna ethanol extract in the absence and presence of fluconazole. The highest antifungal activity was observed against A. treus. The ethanol extract of S. saligna enhanced the antifungal activity of fluconazole against A. niger and A. treus and A. flavus. At the highest tested contents (4 mg/disk), 1.15-, 0.64-, and 2.47-fold increases in inhibition zone surface area were observed for A. niger, A. treus, and A. flavus, respectively. However, no enhancing effect was observed for this plant extract against Aspergillus fumigates at tested contents (0.5, 1, 2, 3, and 4 mg/disk). In a separate experiment, the general cytotoxicity of the ethanol extract of S. saligna was examined with brine shrimp assay. This plant extract showed low cytotoxicity against Artemia salina (LC₅₀ = 186 μg/ml).     

The nonlinear dynamic analysis of the ball-spring automatic balancer by the multiple scales method

Archive of Applied Mechanics - Utilizing ball-type auto-balancer in rotating systems is a popular method in industry in order to eliminate the rotational vibration. Recently, by using numerical...     

Synthesis of the acid–base bifunctional hybrid catalyst via covalently anchored organomoieties on to the SBA-15: a recyclable catalyst for the one‐pot preparation of 1‐amidoalkyl‐2‐naphthols

Research on Chemical Intermediates - In this research, SBA-amino-amido-carboxylic acid (SBA-NH-NHCO-COOH) is synthesized by nucleophilic substitution of SBA propylchloride (SBA-Cl) with ethylene...     

Heavy metals assessment in the hair of street children by INAA method,Isfahan

The street children phenomenon is an increasing problem in most cities of the world including Isfahan, which is a fast growing town. The number of street children with the growth of the town is increased. It is therefore important to have baseline data on their health problems. Hair element analysis remains an important tool in the nutritional and environmental assessment of them. A measurement of the elemental concentration in recently-grown hair provides an integrated view of the element status in the follicular cells and their blood supply, unaffected by short term fluctuations in the nutrient intake of the subject. This study aimed to assess heavy metals concentrations in the hair of street children in Isfahan using neutron activation analysis method. The concentration of heavy metals (Cu, Cr, Fe, Hg, Mn, and Zn) of 17 Iranian street children (Isfahan) was examined. Data analysis found that different profiles of the concentrations of Cr, Hg, Mn, and Zn were seen in each sample. These results were discussed with reference to show of environmental effects.