Quantitative analysis of phthalates using a pyrolyzer gas chromatography/mass spectrometry method.

A pyrolyzer gas chromatography/mass spectrometry (GC/MS) method eliminates toxic solvents that burden our environment and can address the crucial problem of the solvent extraction GC/MS method. The purpose of this study is to establish an efficient quantitative analysis method for 10 phthalates that are regulated by the several governments. A change of concentrations over time for phthalates and internal standards was measured to verify the feasibility of using an auto sampler that facilitates analyzing multiple samples. Both standards maintained constant concentrations over the appropriate time for analysis. A certified reference material under the auspices of the Korea Research Institute of Standards and Science was used to verify the calibration curve obtained by the pyrolyzer GC/MS method, and a deviation was considered similar to the solvent extraction GC/MS method. Then, the limit of detection and limit of quantitation values were confirmed for various consumer products. To verify the reliability of the method, a comparative test with several accredited testing institutes was conducted, and the results were within the standard deviations of the results provided by the institutes. These results indicate that the pyrolyzer GC/MS method can be used in not only screening but also in accurate quantitative analysis.

Synthesis of Arenesulfonyl Fluorides via Sulfuryl Fluoride Incorporation from Arynes.

Transition-metal-free multicomponent reactions involving aryne precursors, secondary amines, and sulfuryl fluoride are reported herein. Zwitterionic intermediates formed from the reaction of arynes with amine nucleophiles can capture SO2F2 under mild conditions, offering a novel and practical protocol for the synthesis of 2-dialkyl-, 2-alkylaryl-, or 2-diarylamino-substituted arenesulfonyl fluoride derivatives in good to excellent yields.

Mechanistic studies of magnetically recyclable Pd - Fe3O4 heterodimeric nanocrystal-catalyzed organic reactions.

Recently, we have reported several catalytic applications of new Pd - Fe3 O4 heterodimeric nanocrystals as magnetically separable catalysts. Successful applications of the nanocrystals towards various useful organic reactions such as Suzuki, Heck, and Sonogashira coupling reactions, direct C - H arylation, and Wacker oxidation have been recorded. However, detailed mechanistic courses of the reactions have not been delineated, and it was not clear whether these processes proceeded through a homogeneous or heterogeneous mechanism. Here, we report detailed mechanistic investigations of the reactions employing the Pd - Fe3 O4 nanoparticle catalysts. Suzuki coupling and Wacker oxidation reactions were chosen as two representative heterogeneous reactions employing the Pd - Fe3 O4 catalysts, and general kinetic studies, hot filtration tests, and three-phase tests were carried out for the two reactions. The studies showed that the reactions most probably proceed via a solution-phase mechanism.