Attenuated total reflection infrared (ATR-IR) spectroscopy using a flow-trough cell, i.e., in situ ATR-IR spectroscopy, enables us to measure infrared spectra of a polymer membrane in contact with a liquid. For a set of spectral data acquired under a certein external perturbation applied to the liquid in contact with the polymer membrane, useful chemical information has been successfully obtained by chemometrics. In the presnet paper, in situ ATR-IR psectroscopy applied to studies on biomaterials in contact with water combined with multivariate curve resolution (MCR) and perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscoy is reviewed.
We have investigated a technique for immobilizing enzymes on different sites of the inner wall of a capillary in order to design a capillary enzyme sensor that could enable us to quantify multi-components simultaneously. UV-irradiation patterning by biotin on the inner wall of a bovine serum albumin (BSA) -modified capillary was performed. Biotin-labeled glucose oxidase (B-GOD) and biotin-labeled galactose oxidase (B-GALOD) were immobilized on two different sites after the inner wall of the capillary was treated with an avidin solution. A capillarity-based fluorescence sensing system for D-glucose and D-galactose at several μmol L−1 was designed, which enables simultaneous quantifications of sugars inside the capillary. The immobilization of B-GOD and B-GALOD on the inner wall was achieved by controlling the volume of each enzyme solution. By the capturing fluorescence emitted from each enzyme-immobilized site, which is ascribable to resorfuin formed from Amplex Red in the presence of horseradish peroxidase (HRP), D-glucose and D-galactose both in the concentration range from 1.0 to 20 μmol L−1 can be quantified simultaneously based on the mean fluorescence intensity.
Coenzyme pyrroloquinoline quinone (PQQ) is an important molecule in biology, chemistry and engineering. It has 14 kinds of carbon atoms, and there are 14 peaks in DMSO-d6 on the 13C-NMR measurement. The disodium salt of PQQ (Na2PQQ), used as food, is not dissolved in DMSO. A 13C-NMR assignment of Na2PQQ in deuterium oxide has not been reported. As for the measurement with a high sensitivity detector (cryo detector), 28 peaks could be observed in deuterium oxide. A quantum chemical calculation revealed that it has two states in equilibrium with the acetal structure by the addition of water to the quinone moiety.
Polygala Radix ("Onji") is an important crude drug used in Kampo formulation. So far, there is only one established quantitative analytical method for separating the impurities of polygalaxanthone III from Polygara Radix. However, it is difficult to simultaneously perform quantitative analysis for 3,6'-disinapoyl sucrose with polygalaxanthone III, because the analysis time is very long (retention time; 240 min). Therefore, our aim is to develop an ultra high-performance liquid chromatography technique that can be used with a very short analytical time (retention time; 27 min). We hope that this method will become an important and effective means for conducting on-site quality assessments in the future.
Abstract Rapid screening methods for asbestos in disaster debris by polarized light microscopy (PLM) and near-infrared spectrometry (NIR) were investigated. In PLM method, disaster debris samples were initially observed with a stereomicroscope to find any fibrous materials. If fibrous materials were found, they were observed by PLM to identify whether they were asbestos or not. The validity of these PLM and NIR methods was confirmed by a field test performed at a disaster waste depot site. Thirty-two debris samples were collected and analyzed by PLM and NIR methods. The screening results were evaluated by comparing the results obtained by a conventional old JIS method. It was confirmed that these rapid screening methods were sufficiently reliable for the on-site screening of asbestos because they presented high correct answer rates (94 % for PLM and 88 % for NIR). Though these methods sometimes reported false negatives for samples of which asbestos concentrations were below 3 %, they can be used for on-site screening because almost all building materials contain asbestos of more than 5 %. The screening periods per sample were about 15 minute for PLM method and about 1 minute for NIR method. Both PLM and NIR methods can be used for on-site rapid screening for asbestos in disaster debris or damaged buildings.
The results of the International Inter-Comparison Exercise (IICE) of a fish certified reference material suggested that true coincidence summing (TCS) correction by a method widely used in Japan is insufficient for 134Cs. Thus, the committee for the preparation of reference materials for radioactivity analysis of JSAC conducted a collaborated experiment for the determination of 134Cs and 137Cs radioactivity of standard sources of those nuclides to validate the TCS correction from 4th January to 4th April 2017. A total of twelve Japanese laboratories participated in this experiment. Two standard sources of 134Cs, and a mixture of 134Cs and 137Cs with cylindrical shape were passed along the laboratories to determine the radioactivity of 134Cs and 137Cs of the sources. The metrological traceability is ensured in terms of the radioactivity of the standard sources. The laboratories analyzed the standard sources using a gamma-ray spectrometer, and reported the analysis results together with measured raw data and their related information to the organizer. The measured data were analyzed by the organizer using two Japanese gamma-ray spectrum analysis programs independently. The analysis results between the laboratories and the organizer almost agreed. The analysis results of 134Cs and 137Cs of two standard sources were lower by 2.3 % to 5.2 % than the reference values. While the –2.3 % difference for 137Cs is still within the rage of the standard uncertainty of the reference value, the –2.7 % to –5.2 % differences for 134Cs were out of the standard uncertainty range of the reference values concluded that the differences for 134Cs is created due to the insufficient correction of TCS.