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Volume 66, Issue 7
Displaying 1-7 of 7 articles from this issue
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Annual Topic “photo” : Analytical Reports
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Mamoru AKUTSU, Ken-ichi SUGIE, Koichi SAITOArticle type: Annual Topic “photo” : Analytical Reports
2017 Volume 66 Issue 7 Pages 477-486
Published: July 05, 2017
Released on J-STAGE: August 08, 2017
JOURNAL FREE ACCESSPhotoionization (PI), a soft ionization technique, can provide molecular ion information without causing complete fragmentation of the molecule. Gas chromatography/mass spectrometry in the PI mode (GC-PI/MS) involves ionizing sample molecules with light energy at approximately 8–10 eV. In this study, we examined the potential application of GC-PI/MS for the analysis of 209 new psychoactive substances (NPSs), originating from raw materials that are largely abused. GC-PI/MS allowed us to observe the molecular ions of all of the substances we examined. Some of these compounds showed only the molecular ions in the mass spectra; i.e., no fragment ions were observed. The mass spectra of other compounds showed fragment ions at varying intensities in addition to the molecular ions. Accordingly, we attempted to determine the cleavage difference between the two spectra of PI/MS and electron ionization/mass spectrometry (EI/MS) theoretically. Moreover, we created a private reference library of the PI/MS spectra using the software NIST14 Mass Spectral Library, installed in the control system; we registered the additional PI/MS spectrum data of the 209 compounds tested. After creating the new PI/MS spectrum library, we measured the NPS samples with GC-EI/MS and GC-PI/MS, which showed that the EI/MS spectrum data are not sufficient to identify any unknown compounds, but can be supported using the new PI/MS reference library. We have demonstrated that GC-PI/MS can be an invaluable technique for providing additional structural information when analyzing NPSs.View full abstractDownload PDF (1224K)
Accounts
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Yo TANAKAArticle type: Accounts
2017 Volume 66 Issue 7 Pages 487-494
Published: July 05, 2017
Released on J-STAGE: August 08, 2017
JOURNAL FREE ACCESSA microchip (also so-called micro fluidic chip or micro chemical chip) is a palm-sized small board with micro and nano fluidic channels fabricated by micro or nano machining techniques. It is widely utilized for the integration of complicated chemical and biochemical experimental processes. This is a spin-off technology from integrated-circuit fabrication techniques in the field of electronics and information technology. Currently, it is applied to various wet processes in chemistry and biology. A number of sophisticated systems have been developed up to now. There are several advantages, including saving the amount of chemical reagents used and short analysis time. By exploiting these significant advantages, various kinds of chemical systems, such as analysis, synthesis and cellular experiments, have been integrated onto a microchip. Regarding this microchip technology, the author has developed several original technologies concerning fabrication, fluid control and construction of mechanical devices for bio-analysis. For example, totally glass-based micro valves, pumps, filters and ultra thin, flexible glass microchips have been demonstrated based on ultra-thin glass sheet handling techniques. Moreover, cell function-based devices working in novel principle based on this microfluidic technology, such as a cardiomyocyte-based pump or an electric organ-based power generator have been developed. In this review, these achievements are comprehensively introduced.View full abstractDownload PDF (1121K)
Research Papers
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Michiko EGAWA, Shogo SUGAHARA, Yasushi SEIKEArticle type: Research Papers
2017 Volume 66 Issue 7 Pages 495-502
Published: July 05, 2017
Released on J-STAGE: August 08, 2017
JOURNAL FREE ACCESSWe have developed a novel continuous fractional extraction method for the determination of inorganic phosphorus (Fe-P, Al-P, and Ca-P) in bottom sediments. This method uses a sodium sulfide (Na2S) solution as the extracting solvent for Fe-P from wet sediment. The Na2S solution reacted with Fe-P to form as a FeS precipitate and a soluble phosphate. The mixture was filtered and the phosphate concentration in the filtrate was determined by the molybdenum blue method. Initially, excess hydrogen sulfide inhibited any color development of molybdenum blue. We removed hydrogen sulfide by adding a mixed diamine solution to form methylene blue. The resulting colored solution was passed through a Sep-Pak C18 cartridge to remove the methylene blue. The hydrogen sulfide-free effluent was used for the determination of phosphate. Sodium hydroxide (1 mol L−1) and hydrochloric acid (1 mol L−1) was used as extracting solvents for Al-P and Ca-P, respectively. The proposed method was successfully applied to bottom sediments from brackish water areas.View full abstractDownload PDF (793K) -
Yoshimi SHIRAMIZU, Masaru TANAKA, Hideji TANAKA, Masaki TAKEUCHIArticle type: Research Papers
2017 Volume 66 Issue 7 Pages 503-508
Published: July 05, 2017
Released on J-STAGE: August 08, 2017
JOURNAL FREE ACCESSThis paper describes the automated basic gases measuring technology for the near-real-time monitoring of ammonia (NH3) and amines in a clean room. The analytes collected with a parallel-plate wet denuder (PPWD) are continuously pumped into one of two cation concentration columns for 15 min, and determined on-line by means of ion chromatography. While one concentration column is used for chromatographic separation, the other is used for loading the sample solution. The PPWD collects quantitatively mono ethanolamine (MEA) gas at a sampling flow rate of 2.5 L min−1. The response time to any variability in the MEA gas concentration is fast enough for near-real-time monitoring. The limits of detection are 0.005 μg m−3 for NH3 gas, 0.01 μg m−3 for MEA gas, and 0.02 μg m−3 for N-methylethanolamine (N-MEA) gas. The NH3 and N-MEA gas concentrations have been successfully measured at semiconductor manufacturing clean rooms.View full abstractDownload PDF (765K) -
Toshio TAKAYANAGI, Masashi ISODA, Daichi ITOH, Hitoshi MIZUGUCHIArticle type: Research Papers
2017 Volume 66 Issue 7 Pages 509-514
Published: July 05, 2017
Released on J-STAGE: August 08, 2017
JOURNAL FREE ACCESSHydrochlorothiazide, one of the popular diuretics, is degradable in an aqueous solution by hydrolysis, gradually forming 4-amino-6-chloro-m-benzenedisulfonamide. Upon determining the physicochemical constants such as acid dissociation constant (pKa), the coexistence of any degraded species is not desirable. However, equilibrium analysis with the effective electrophoretic mobility measured by capillary zone electrophoresis (CZE) can allow the coexistence of such degraded substances. In this study, acid dissociation constants were determined by CZE with hydrochlorothiazide (HCT) under its degraded conditions. Two steps of the successive acid-dissociation constants have been determined with HCT as pKa1 = 8.95±0.04 and pKa2 = 10.66±0.07; the values agree well with those determined with a freshly prepared HCT solution. Further, two steps of the successive acid-dissociation constants were also determined with the degradant from HCT, 4-amino-6-chloro-m-benzenedisulfonamide, by the CZE analysis utilizing the resolution of the degradant from HCT; pKa1 = 9.27±0.06 and pKa2 = 10.79±0.10 were determined. The potential of the equilibrium analysis by CZE was demonstrated with the degradable HCT.View full abstractDownload PDF (748K)
Technical Papers
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Toshiko ITAGAKI, Tetsuya ASHINO, Kazuaki WAGATSUMAArticle type: Technical Papers
2017 Volume 66 Issue 7 Pages 515-520
Published: July 05, 2017
Released on J-STAGE: August 08, 2017
JOURNAL FREE ACCESSThis paper reported on the analytical precision in flame atomic absorption spectrometry when an internal standard method, in which absorption lines of the analyte and internal standard element were measured sequentially (sequential method), was applied by using a continuum-light source spectrometer. For comparison, our previous paper regarding an internal standard method by measuring them simultaneously (simultaneous method) was also referred to. Relationships between the absorbance and iron concentration and the ranges of their linear calibration were investigated for 23 iron atomic lines (as the internal standard line), so that an optimum iron line could be selected for the internal standardization. The result indicated that the allowable range of the concentration could be predicted from the product of the relative number density and the transition probability of these absorption lines. The sequential method for an internal standard was carried out in the determination of nickel in a steel sample, to correct for any physical interference occurring in a flame and a drift of the signal response in the measurement. In conclusion, the analytical precision in the sequential method was less improved than that in the simultaneous method.View full abstractDownload PDF (725K)
Notes
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Hideaki MINAMI, Jun’ichirou KADONOArticle type: Notes
2017 Volume 66 Issue 7 Pages 521-528
Published: July 05, 2017
Released on J-STAGE: August 08, 2017
JOURNAL FREE ACCESSThe composition of double-sided tapes available for X-ray fluorescence analysis was investigated and the double-sided tapes were classified into the detected composition. As a result, Na, Mg, Al, Si, P, S, Cl, K, Ca, Fe, Ti, Ag and Sr were detected from double-sided tapes; they could be classified into 4 types: 1) Si, S, Ca; 2) Na, Si, P, S, K; 3) Si, P, S and 4) Al, Ca. Double-sided tape made of polyester and polypropylene had fewer elemental component detected than that made of paper and non-woven fabric. Si derived from the release agent was detected with most double-sided tapes. Standard materials were measured with paper double-sided tape, which were affected by coexisting elements. On the other hand, when measuring a standard material with polypropylene double-sided tape, no influence of coexisting elements was observed.View full abstractDownload PDF (1622K)
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