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We measured the enantiomeric fractions (EF) of various organochlorine pesticides in air samples from Indiana, Arkansas, and Louisiana collected in 2002–2003. Enantiomeric fractions for o,p′-DDD are reported here for the first time, and they suggest preferential depletion of one enantiomer over the other, with a mean value of 0. 44. For the chlordanes, the EFs followed the same trends as reported in previous studies. EF values for trans-chlordane (TC) were slightly below 0. 5, and values for cis-chlordane (CC) were slightly above 0. 5. For cis-heptachlor epoxide (HEPX), the EF values averaged 0. 65, indicating a clear preferential depletion of the (−)-enantiomer. For TC and CC, no clear distinction could be made between the values measured among the three sites, suggesting that it is not possible to use these EF values as “source signatures”. For HEPX, the Indiana site had significantly higher EF values than did the Arkansas site; this difference may reflect differences in the historic use of heptachlor in these two regions. [Copyright &y& Elsevier]

The article presents a calendar of events related to liquid chromatography in the U.S. The 21st International Symposium in Microscale Bioseparations will be on January 13 to 18, 2007 in British Columbia, Canada. The PharmaMedDevice Conference and Exhibition will be on April 23 to 25 in New York City. the Chirality-2007: 19th International Symposium on Chirality will be held on July 8 to 11, 2007 in San Diego, California.

The article presents a calendar of events that lists meetings and symposia related to instrumentation science in the U.S. for 2006. The 4th International Symposium on Countercurrent Chromatography will be held on August 8-11, 2006. The International Activated Carbon Conference will be held on October 19-20, 2006. The 19th International Symposium on Chirality will be held on July 8-11, 2007.

This article focuses on a probe on the enantioselectivity of chiral pesticides. It examines as well as evaluates various aspects of chiral pesticides. Around one fourth of all pesticide active ingredient are chiral. These chirals exist in the form of two mirror images that is called enantiomers. The difference in the biological properties of chirals has led to increased research on the enantioselectivity of compounds such as the phenoxypropionic acid, herbicides, especially dichlorprop and mecoprop. A prolonged research work is being carried out by the scientists on phenomenon of enantiomer selectivity of chiral pollutants and its impact on pollutant exposure and fate. The article also informs about the existence of many chiral environmental pollutants, which makes their presence besides pesticides and polychlorinated biphenyls (PCBs). The studies have revealed that several chiral PCB congeners exist in non-racemic concentrations in lake and river sediments. The Environmental Protection Agency of the United States evaluates the potential for enantioselectivity in its risk assessments of chiral pesticides. After this assessment the agency has implemented an interim policy that focuses on optical stereoisomers and evaluates the relative risks of enantiomers.

Both 1-methylisopropyl 2-(2-hydroxyethyl)piperidine-l-carboxylate, (Picaridin®) and cyclohex- 3-enyl 2-methylpiperidin-l-yl ketone (A13-37220; 220) have two asymmetric centers, and the four diastereoisomers of each compound are known to have differing degrees of mosquito-repellent activity according to quantitative behavioral assays conducted at the United States Department of Agriculture. Computational chemistry was used to identify the structural and configurational basis for repellent activity. Molecular overlay of the optimized geometries of the lowest energy conformers of the diastereoisomers was investigated to elucidate the rote of chiral centers in 220 and Picaridin. It was found that the presence of a chiral carbon alpha to the nitrogen with the S configuration in the piperidine ring is essential to the three-dimensional arrangement of the atoms of the phannacophore for effective repellent activity. [ABSTRACT FROM AUTHOR]

This article presents information on meetings and symposia related to science in the year 2005-2012. Some of the meetings were the International Conference on the Biogeochemistry of Trace Elements-ICOBTE at Adelaide, South Australia on April 8, 230 ACS National Meeting in Washington, DC on August 28, Third International Symposium on All Aspects of Plant and Animal Boron Nutrition in Wuhan, China on September 9-13, HPLC 2006, 30th International Symposium and Exhibit on High Performance Liquid Phase Separations and Related Techniques at Marriott Hotel, San Francisco, California, 19th International Symposium on Chirality (ISCD), California on July 2007.

The article features a research that investigates the efficacy of electrochemical method to differentiate and to separate excess enantiomers (ee) of binol utilizing redox-active boronic acids as chiral sensors in the U.S. Researchers found the technique to be efficient because it accurately determines ee. Moreover, they observed low analyte concentrations sensitivities, making it a promising option for ee evaluation.

The article discusses the concept of teaching chirality in chemistry classes in the U.S. According to the author, chiralty is the property of molecules of objects that contains non-superimposable properties in the image which often leads to optical activity when its enantionmers rotate in a polarized plane in opposite direction. In addition, the author added that the chirality of an object can be asserted through the comparison of its mirror images which helps students easily identify chiral centers in molecules. It also discusses the chiral concept associated in the various cutting ways of apple as well as the procedures on how to carry out the procedure.

Features the 16th International Symposium on Chirality, held in New York City on July 11-14, 2004. Scientific program; Topics that will be covered.