Liquid–liquid extraction of Hg(II) from acidic chloride solutions using bis‐2‐ethylhexyl sulfoxide

The liquid–liquid extraction of Hg(II) from acidic chloride solutions has been studied using bis‐2‐ethylhexyl sulfoxide (B2EHSO) as an extractant. For comparison, extraction studies have also been carried out using di‐n‐octyl sulfoxide (DOSO) and diphenyl sulfoxide (DPhSO). The extraction data have been analysed by both graphical and theoretical methods taking into account aqueous phase speciation and all plausible complexes extracted into the organic phase. These results demonstrate that Hg(II) is extracted into xylene as HgCl₂.3R₂SO (where R₂SO represents the sulfoxide). The equilibrium constant of the extracted complex has been deduced by non‐linear regression analysis. The developed liquid–liquid extraction procedure has been applied for the recovery of mercury from the brine‐sludge of a Chlor‐Alkali plant. © 2001 Society of Chemical Industry     

Solvent extraction separation of vanadium(V) from multivalent metal chloride solutions using 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester

The solvent extraction behaviour of vanadium(V) from hydrochloric acid solutions has been investigated using 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester (EHEHPA ≡ HX) in kerosene as an extractant. For comparison, extraction studies have also been carried out with vanadium(IV). The results demonstrate that the extraction of vanadium(V) follows the cation exchange mechanism: where (HX)₂ refers to the dimeric form of EHEHPA. On the other hand, two dimeric molecules of EHEHPA were found to be involved in the extracted complex of vanadium(IV): The equilibrium constants of the above extracted complexes have been calculated and found to be K_ex,V(V) = 3.14 and K_ex,V(IV) = 0.32. The effect of the nature of the diluent on the extraction of vanadium(V) with EHEHPA has been studied and correlated with the dielectric constants. IR spectral studies of the extracted complex were used to further clarify the nature of the extracted complex. The separation and recovery possibilities of vanadium(V) from other associated metal ions, viz magnesium(II), aluminium(III), titanium(IV), chromium(III), manganese(II) and iron(III), which are present in the waste chloride liquors from the processing of titanium minerals, are also discussed. © 2002 Society of Chemical Industry     

氟啶虫胺腈对桃蚜和瓜蚜室内杀虫活性及田间防治效果

通过室内毒力测定及田间药效试验评价氟啶虫胺腈原药以及22%氟啶虫胺腈悬浮剂和50%氟啶虫胺腈水分散粒剂对桃蚜和瓜蚜的杀虫活性。分别采用浸叶法和常规喷雾法进行室内毒力测定和田间药效试验。室内毒力测定结果表明,氟啶虫胺腈原药对桃蚜和瓜蚜48 h LC50值分别为0.98 mg/L和1.70 mg/L,氟啶虫胺腈对桃蚜和瓜蚜的相对毒力分别是啶虫脒的4.2倍和2.0倍。田间药效试验结果表明,22%氟啶虫胺腈悬浮剂和50%氟啶虫胺腈水分散粒剂对桃蚜和瓜蚜具有很好的速效性和持效性,平均防治效果为82.0%~96.0%。氟啶虫胺腈可有效防治桃蚜和瓜蚜,是农业生产上防治蚜虫的理想药剂之一。     

Near-infrared reflecting inorganic pigments based on molybdenum and praseodymium doped yttrium cerate: Synthesis, characterization and optical properties

A series of novel environmentally benign near-infrared (NIR) reflecting inorganic pigments based on yttrium cerate doped with metal ions such as Mo⁶⁺ or Pr⁴⁺ have been developed and characterized using XRD, UV-vis-NIR diffuse reflectance spectroscopy and CIE 1976 L^?a^?b^? color scales. The substitution of Mo⁶⁺ for Ce⁴⁺ in Y₂Ce₂O₇ changed the color from ivory-white to yellow and the band gap decreased from 3.01 to 2.44 eV due to O_2p-Mo_4d charge-transfer transitions. Most importantly the molybdenum doped pigments exhibit bright yellow hue with high NIR solar reflectance (>90%) in the range 700-2500 nm. In contrast, replacing Pr⁴⁺ for Ce⁴⁺ drastically shifts the absorption edge of the pigments from 410 to 725 nm and as a result the band gap of the compounds changes from 3.01 to 1.70 eV. Interestingly, the praseodymium doped pigments not only exhibits colors ranging from brick-red to dark-brown but also shows significant NIR solar reflectance. The ability of the pigments to transfer their NIR reflectance properties to a roofing material like asbestos cement sheet was evaluated.     

Quantitative method for the profiling of the endocannabinoid metabolome by LC-atmospheric pressure chemical ionization-MS

The endocannabinoid system's biological significance continues to grow as novel endocannabinoid metabolites are discovered. Accordingly, a myopic view of the system that focuses solely on one or two endocannabinoids, such as anandamide or 2-arachidonoyl glycerol, is insufficient to describe the biological responses to perturbations of the system. Rather, the endocannabinoid metabolome as a whole must be analyzed. The work described here is based on liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry. This method has been validated to quantify, in a single chromatographic run, the levels of 15 known or suspected metabolites of the endocannabinoid system in the rat brain and is applicable to other biological matrixes. We have obtained an endocannabinoid profile specifically for the frontal cortex of the rat brain and have determined anandamide level differences following the administration of the fatty acid amide hydrolase inhibitor AM374.