Purity assay of high-purity materials (HPMs) of phthalic acid esters (PAEs) was carried out by means of a mass balance method. In this method, chromatographic methods such as gas chromatography-flame ionization detector (GC-FID) and/or high-performance liquid chromatography (HPLC) in combination with other methods such as Karl-Fischer (KF) titration and vacuum evaporation (VE) were applied. The sum of the impurities estimated by these methods allowed the estimation of the purity of the main component by difference. Seven PAEs with varying side chain structures and levels of impurities were analysed on a systematic way in which impurities were classified into several groups in terms of their abundance, availability of qualitative information and availability of authentic compounds, etc. The absolute quantity of each impurity was determined by GC-FID and/or HPLC based on the calibration made by the authentic compounds of impurities whenever available. The purities in mass fraction of these PAEs were certified at the National Metrology Institute of Japan (NMIJ), and the PAEs were registered as primary reference materials playing an essential role in linking the metrological traceability of the Japan Calibration Service System (JCSS) to the International System of Units (SI).
Plant parasitic nematodes are the most destructive group of plant pathogens worldwide and their control is extremely challenging. Plant Essential oils (EOs) and their constituents have a great potential in nematode control since they can be developed for use as nematicides themselves or can ... more
For over a century, ulcer has been a major cause of morbidity and mortality. Its treatment has progressed from vagotomy to proton pump inhibitors. However, the drugs used produce many adverse effects and are less effective than they ought to be. Therefore, there is a growing interest in alt ... more
Endophytic fungi are ubiquitous organisms found in the plants, residing intercellular or intracellular, at least for a portion of their lives without causing apparent symptoms of infection. Almost all plants are known to harbor endophytes. The choice of the plant to be used for exploring en ... more
Physicists describe how they have synthesized a new material that belongs to the iron-selenide class of superconductors, called LixFe2Se2(NH3)y, in a paper about to be published in EPJ B. The work was carried out by Ernst-Wilhelm Scheidt from the University of Augsburg and colleagues. This ... more
The U.S. federal government is significantly underestimating the costs of carbon pollution because it is using a faulty analytical model, according to a new study published in the Journal of Environmental Studies and Sciences. A more appropriate accounting of costs would pave the way to cle ... more
Springer advisory board member Vladimir V. Dmitriev, along with fellow scientists Yuriy M. Bunkov and Igor A. Fomin, have been named winners of the 2008 Fritz London Memorial Prize for their discovery and understanding of the "Phase Coherent Spin Precession and Spin Superfluidity of 3He-B." ... more