Publications by authors named "Kayo Yanagisawa"

For quantitative visualization of trace elements, an online isotope dilution (ID) laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) method capable of accurately correcting the detection amount of targets is presented. Two aerosols from an ablated sample and a nebulized isotopically enriched spike solution were mixed online using a dual-port spray chamber. In this paper, transmission efficiency (TE) of each of the two gas streams to the ICP-MS detector is revealed, and the quantification values were corrected by including the ratio of TEs in the calculation of the online ID method.

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We demonstrate the sensitivity enhancement in inductively coupled plasma mass spectrometry (ICP-MS) by combining ultrasonic nebulization via the nitrogen mixed gas effect. We showed the effect of nitrogen gas concentration (0-5%) in the nebulizer gas on the signal sensitivity for 63 elements using commercially available (concentric and ultrasonic) nebulizers. In addition, the limit of detection (ng L) was calculated in each case.

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Due to the lack of a correlation with the natural Strontium (Sr) isotopes, it is difficult to apply the isotope dilution (ID) method to an artificial radioactive mononuclide Strontium-90 (Sr), in inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS). Meanwhile, online solid-phase extraction (SPE)-ICP-QMS (SPE-ICP-QMS) serves as an automatic sequential analytical technique for measuring the ultra-trace amounts of radionuclides; however, apparent assay values obtained using this method are often negatively affected by differences in the sample matrix composition between standard and actual samples. In this study, the pg L level of Sr was successfully measured by combining online SPE-ICP-QMS and the ID method with Sr/Sr ratios in one sample injection, without the radioactive standard.

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In this paper, we propose an online dilution system for the rapid quantification of radioactive strontium-90 (Sr) with inductively coupled plasma mass spectrometry coupled solid-phase extraction and O dynamic reaction (cascade ICP-MS). The proposed system automatically provides a higher dilution ratio, which is at most 3.3 ± 0.

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Protein integration into biological membranes is a vital cellular event for all organisms. We previously reported an integration factor in the inner membrane of Escherichia coli, named MPIase (membrane protein integrase). Here we show that in contrast to previously identified integration factors that are proteins, MPIase is a glycolipid composed of diacylglycerol and a glycan chain of three acetylated aminosugars linked through pyrophosphate.

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