A method for the simultaneous determination of K, Mg and Ca in milk was studied by ion chromatography (IC) after deporoteinization with perchloric acid. Perchloric acid for deporoteinization was a better solution than other solutions, such as hydrochloric acid, sulfuric acid, acetonitolile addition, ultrafiltration of diluted milk solution, for the extraction of total K, Mg and Ca from milk. The recommened procedure was as follows: 1.0 mL of an aliquot of milk samples and 0.1 mL of 1.0 M perchloric acid were pipetted into glass tube. After degeneration for 30 min, it was diluted to 50 mL by pure water, and filtration using membrane filter, 100 μL of the resultant solution was analyzed by IC. About a non-suppresser type IC, Shodex IC YS-50 (4.6 mm i.d. × 125 mm) and 4 mM methanesulfonic acid were used as a separation column and a mobile phase, respectively. The detection limits of the conductivity (S/N = 3) were 25 μg L⁻¹ for K, 53 μg L⁻¹ for Mg and 50 μg L⁻¹ for Ca. The relative standard deviation (RSD, n = 10) was less than 1 % for K, Mg and Ca. The values obtained by this method for 1454–1495 mg L⁻¹ for K, 94–110 mg L⁻¹ for Mg and 1077–1095 mg L⁻¹ for Ca, which agreed well with those by ICP-OES.

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A simultaneous and quantitative analysis of 5 elements including sulfur, fluorine, chlorine, bromine and iodine in pharmaceutical compounds was studied using a XS-2100H elemental analyzer. Anomalous values were obtained in the analysis of bromine and iodine in sulfur-containing compounds using the XS-2100H elemental analyzer in the factory default made. We focused on the gas trap tube to fall to the normal values of bromine and iodine. Highly accurate analytical results were obtained by improving the XS-2100H elemental analyzer with our invented device.

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A method for the rapid and simultaneous micro-analysis of organic halogens and sulfur that employs a novel coupled combustion - ion chromatography (IC) apparatus is described in detail. The cost has been decreased by switching from argon (helium) - oxygen for the carrier gas to cleaner air. In addition, a standard sample that contained 4 halogens and sulfur was developed concerning the making of calibration curves. A sample of 1.0–10 mg (micro) or 0.1–1.0 mg (ultra-micro) was weighed and ignited in a quartz combustion tube at 1000 °C. The combustion products were collected in a 40 mL (total volume) of mixed solution of very tin hydrogen peroxide and hydrazine hydrate. After a 50 μL aliquot of each sample solution was injected into a suppressed conductivity IC system. The calibration curves of the peak areas of each element (F, Cl, Br, I and S) were obtained from the combustion standard (NAC-st4: C₁₂H₇NO₂FClBrIS) with high correlation coefficients (r²) of more than 0.999. The 5–6 samples per one hour were able to be analyzed by this combustion/IC system within 0.3 % of the theoretical values.

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We developed an easy-to-use analytical method for amyloid fibrils by high-performance liquid chromatography (HPLC) with post column fluorescent labeling. Thioflavin T (Th T), which was used widly as a labeling agent for amyloid fibrils, is a traditional probe for the confirmation of amyloid fibril formation. Although the traditional fluorescence spectroscopy measurements are used for monitoring the aggregation reaction, they have no applicability to separation analysis of the amyloid fibrils. In order to understand the fibril formation process, the development of an efficient method that enables to separate and detect the amyloid fibrils is required. In this work, Th T labeling of amyloid fibrils in 1 mM hen egg white lysozyme (HEWL) solution was performed following separation of different-sized amyloid fibrils in a PTFE tube (5000 × 0.50 mm i.d.) as a separation field. The fluorescence was monitored at 485 nm, with the maximum excitation wavelength at 435 nm. The novel method's sensitivity for the detection of amyloid fibrils was high and compared well with the traditional fluorescence spectroscopy measurements. In addition, the developed method detected more than 5 peaks within 20 min under the optimum separation conditions. These results suggest that this analytical method is used to understand the amyloid fibril formation process.

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Chemical components (Na⁺, NH₄⁺, K⁺, Mg²⁺, Ca²⁺, F⁻, Cl⁻, NO₂⁻, Br⁻, NO₃⁻, PO₄³⁻, SO₄²⁻) of fresh rime and snow collected on the summit of Mt. Kajigamori (ALT. 1400 m), Kochi, Shikoku Island in West Japan, where there is a watershed protection forest of Riv. Yoshinogawa during winter season of 2008–2014 y. was obtained with [Pb] and [Cd]. In both the rime and snow precipitated under similar back trajectories in a one day meteorological event, there was a strong positive correlation (r² = 0.9665, [Pb]/[Cd] = 35±1.9) in [Pb] vs. [Cd] plots, indicating the same origin. The ratio was in agreement with the ratio of 37 for the emission in Shandong, China (37). In the case of these metals vs. [nss-SO₄²⁻] plots although there was a good positive correlation in snow, there was an incorrect correlation in the rime. In some rimes, an excess [nss-SO₄²⁻] could be found more than [nss-SO₄²⁻] calculated based on the proportionality in the snow at its [Pb], indicating the existence of different types of origin of nss-SO₄²⁻ species in the south Liaoning, China. In rime (2014–2012 y.) and snow (2014–2013 y), it was found that a good positive correlation (r² = 0.9038, 32±3) and (r² = 0.9173, 38±3) in [Pb] vs. [Cd] plots, respectively, when back trajectories passed through around Liaoning-south Jilin area and around Bohai. In the case of these metals vs. [nss-SO₄²⁻] plots, there were two individual good positive correlations in only the rime. In order to treat the same manner as the one-day sampling, the excess [nss-SO₄²⁻] estimated in rime was attributed to urban aerosol around northeast China. It was considered that the excess [nss-SO₄²⁻]. When the back trajectories passed through around Korea, the ratio of [Pb]/[Cd] = 15±2 (r² = 0.9355) corresponded to that of 14 for the ratio collected in winter season at rural area of near Seoul, Korea.

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Laser desorption/ionization mass spectrometry was performed to one of polycyclic aromatic hydrocarbons (PAHs), pentacene (Pen), doped in mixed crystals of anthracene (Ant) and tetracene (Tet). By changing the mixing ratio of molecules, it was understood that Pen was ionized efficiently by 2-step excitation energy transfer among three molecules when the molar amount of Pen was more than –10 times larger than that of Tet. Possible mechanism of energy transfer was discussed.

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