A selective colorimetric chemodosimeter for the naked eye detection of benzoate anion

A new semicarbazide biphenyl derivative is able to act as a selective chemodosimeter for benzoate.     

An anticipative hyperbolic discount utility on intertemporal decision making

Discount utility is facilitated to scrutinize human decision behaviors for different points in time under the consideration of time preference. Recent studies are extended from two basic models, which are the exponential and the hyperbolic discount models, and the more popular hyperbolic discount model is well recognized for resolving the effects of preference reversal and is less steeply discounting than the exponential discount model. However, to enhance the capability of explaining intertemporal decision making behavior, an anticipative hyperbolic discount utility model was proposed which revised the conventional hyperbolic discount utility by introducing the anticipative parameters under the consideration of anticipation of future gains or losses. An empirical investigation was employed to validate the effectiveness of the proposed anticipative hyperbolic discounting utility model, which was able to empirically go beyond the traditional hyperbolic discounting utility model. Also, the proposed anticipative hyperbolic model is capable of dealing with the anomalies of preference reverse and framing effects.     

Validation of stir bar sorptive extraction for the determination of 24 priority substances from the European Water Framework Directive in estuarine and sea water

This paper describes the validation of a method for the determination of 24 priority substances from the European Framework Directive in estuarine and sea water using the new extraction technique known as stir bar sorptive extraction (SBSE), followed by thermal desorption using capillary gas chromatography-mass spectrometry. We studied linearity, detection and quantitation limits and accuracy (which includes determination of trueness and precision). Using the lack-of-fit method we tested linearity in the 0-200 ng L⁻¹ range for all the priority substances. The detection and quantification limits were less than 5 and 10 ng L⁻¹, respectively, for most of the compounds studied. Precision was assessed by variance analysis (ANOVA) and relative standard values of less than 10% were obtained for repeatability and less than 15% for intermediate precision. The recovery percentages in spiked estuarine and sea water were close to 100%. Finally, for quality control of the method (stability of precision and accuracy through time), we developed a method for calculating Shewhart control charts based on the information obtained in the validation process.     

A new class of chiral pyrrolidine for asymmetric Michael addition reactions. New mechanism via simple 4+2 type attack of the enamine on the trans-nitrostyrene

A new chiral organocatalyst is described in this paper. A new mechanism for the overall Michael condensation of ketones with nitroolefins using our catalyst is suggested based on molecular modelling studies.     

Recent developments in asymmetric catalytic addition to CN bonds

Methods for enantioselective C-C bond constructions via additions to imines and related compounds are reviewed, with an emphasis on the most recent efforts involving asymmetric catalysis. Selected seminal examples are provided in order to place the recent developments in context.