Using a preparation technique for supercritical fluid (SCF) based on SCF liquid chromatography, a chemiluminescence (CL) reaction analyzer for SCF was developed. The operation of the analyzer is conceptually similar to the method of flow injection analysis (FIA). An SCF is prepared in a high pressure reaction cell through and the SCF leaves through a small diameter stainless steel capillary tube. The analyzer consists of a high pressure pump for SCF, 3 reagent (or sample) injectors, a specially made high pressure reaction cell installed in a thermoregulator, a detector (photomultiplier tube and its operating system) facing on the thermoregulator and a recorder. Notable points of merit for the analyzer are as follows; i) easy operation, ii) analysis of rapid reactions, iii) analysis concerning a high pressure reaction, iv) supply of design information for an SCF-FI/CL system etc.

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An X-ray diffractometric method has been developed for determination of corundum (α-Al₂O₃), spinel (MgAl₂O₄) and aluminium nitride in the scum formed on melt of aluminium alloy. In order to remove aluminium for improved resolution of analysis, the scum was subjected to selective dissolution; Hydrochloric acid (1+1) was used for the determination of corundum and spinel, and a bromine-methanol solution under ultrasonic agitation was used for that of aluminium nitride. Silicon powder of 1/5 in mass was added to the residue as a reference material. Ratios of the integral intensities of strong diffraction lines from the compounds to the peak intensity of silicon (1 1 1) diffraction line were measured. The compounds were determined with linear relations of regression between the intensity ratios and the concentrations of standard specimens. Corundum and spinel in the range of 1828% and aluminium nitride in the range of 26% were determined with standard deviations (SD) of 0.72.4% and 0.2%, respectively; Corundum of 0.8% was determined with an SD of 0.1%.

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A new method for simultaneous determination of several inorganic anions on a ceramic carbon column with a suppressed ion chromatograph equipped with a conductometric detector was tested. Carbon IC BI-02 column (4.6mm i.d.×50mm, Bio Tech Research) was installed in an ion chromatograph (Dionex 4500i) equipped with an anion micromembrane suppressor (AMMS-MPIC). Two mM sodium carbonate containing 1mM tetrabutylammonium hydroxide (TBA) in 5% acetonitrile was the optimal mobile phase for simultaneous determination of a mixture of 8 anions (F^-, Cl^-, NO^-₂, Br^-, NO^-₃, SO^2-₄, HPO^2-₄ and I^-) under the following conditions : flow rate, 1.0ml/min ; scavenger, 12.5mM sulfuric acid ; column temperature, 30°C. Calibration curves obtained from the peak areas of the 8 anions were linear with high correlation coefficients of more than 0.999 and a good relative standard deviation (RSD) of 0.20.9% (n=10). Hydrophobic anions such as I^-, S₂O^2-₃ and SCN^- were separated by using 2mM sodium carbonate containing 1mM TBA in 10% acetonitrile as the mobile phase at a temnerature of 38°C.

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A method for the individual determination and separation of chromium(III) and chromium(VI) by use of Ettringite is described. Ettringite, 3CaO·Al₂O₃·3CaSO₄·32H₂O, is a hydrate of a cement mineral, 3CaO·Al₂O₃ or 4CaO·Al₂O₃·Fe₂O₃ is generated during the begining stages of hydration of the cement with gypsum and water. In this work, synthetic Ettringite is applied to the collection of chromium(III). The analytical procedure is as follows. To a 100ml sample solution (pH13) containing less than 100μg of total chromium, 100mg of synthetic Ettringite is added, and the mixture is stirred for 10 min by a stirrer. The mixture is separated to a solid phase {Cr(III)} and a liquid phase {Cr(VI)} through a membrane filter (Teflon^® MF, pore size: 10.0μm) by vacuum filtration. Solid on the filter is dissolved with 10ml of 4 M hydrochloric acid, and the sample solution is diluted with water to 25.0ml. The sample solution or liquid phase is introduced into the plasma using a concentric nebulizer. The emission intensity of chromium is measured under the following operating conditions: 267.72(II) nm line for chromium, carrier argon flow rate at 0.45l/min, RF power at 1.2kW, and observation height at 13mm. By the proposed method, chromium(III) is separated from chromium(VI), and chromium(III) is quantitatively collected by Ettringite from 100ml to 1000ml of sample solution.

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A method for the determination of trace amounts of Cu in high-purity aluminium has been studied. The high-purity aluminium was dissolved by heating with HCl (1+1) in the presence of Pt wire. Copper in the solution was extracted into xylene in its diethyldithiocarbamate (DDTC) complex form and subsequently back-extracted into 100μl of aqueous phase containing HNO₃ for determination by graphite-furnace AAS. The recovery of Cu was satisfactory on the extraction from aqueous solution containing over 3×10^-3 M of DDTC at pH 1.04.6 and back-extraction using more than 10μl of 98% HNO₃. The foreign elements which are generally contained in 0.2g of high-purity aluminium caused no interference for the determination of Cu. The detection limit of Cu was 3.5ng/g when 0.2g of Al sample was used and the relative standard deviation (n =6) for 10ng of Cu was 6.4%. The proposed method was applied to the determination of Cu in high-purity aluminium samples and a standard reference sample with good results.

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In order to determine impurities in tantalum carbide and tantalum nitride by ICP-AES, sample dissolution procedures by acids were examined. A powder sample of 0.25g tantalum nitride was taken in a Teflon pressure vessel, and 2ml of hydrofluoric acid (1+1) and 1ml of 31% hydrogen peroxide solution were added. After sealing, the vessel was kept at 160°C for 16 h in a drying oven. Though it has been reported that tantalum nitride is insoluble in acids, these tantalum nitride powder samples dissolved completely. After cooling, the solution was transferred to a 100ml calibrated flask with 20ml of 4% boric acid and 5 ml of nitric acid, and diluted with distilled water. A powder sample of 0.25g tantalum carbide was also taken in a Teflon pressure vessel, and 5 ml of nitric acid, 3ml of 31% hydrogen peroxide solution and 1 ml of hydrofluoric acid were added. The vessel was kept at 180°C for 20 h after predecomposition at room temperature for 2 h. This solution was also transferred to a 100ml calibrated flask with 20ml of 4% boric acid. Among the matrix components, the tantalum matrix increased the background level for all the elements without, however, influencing the emission intensities. The increase in the background level was corrected by subtracting the background intensity near each analytical line in ICP-AES measurement. Therefore, the common standard solutions of nitric acid, hydrofluoric acid and boric acid could be used for the determination of impurities in tantalum carbide and tantalum nitride. The proposed method was applied to some commercial samples. The analytical results were in good agreement with those obtained by AAS, and the reproducibility was satisfactory.

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Field desorption MS(FD-MS) has been used to characterize the constituent molecules in benzoguanamine-formaldehyde(B-F) resins. The technique is shown to be a good for the characterization of constituent molecules and their distribution in methylated B-F resin, butylated B-F resin, methylated/ethylated B-F resin and methylated B/melamine (M)-F resin. It is clarified that the dimethylene-ether bonds generate in a condensation reaction by reaction analysis of butylated B-F resin. Moreover, it is shown that many constituent molecules containing M-M, M-B and B-B bonds are present as a mixture of di-nuclear molecules of methylated B/M-F resin. Therefore we can expect to use this technique for further reaction process analyses of B-F resins.

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5-Nitro-2-pyridinecarbaldehyde 5-nitro-2-pyridylhydrazone(5-NPA-5-NPH), in which an electron-withdrawing nitro group was introduced to the 5-position of the pyridine ring in both the hydrazine and aldehyde moiety of 2-pyridinecarbaldehyde 2-pyridyl-hydrazone(PAPH), was found to be most sensitive for the determination of metal ions. In particular, 5-NPA-5-NPH forms a stable 1:2 (metal:ligand) complex with nickel(II), which is quantitatively extracted from aqueous solutions of pH5.5-10.0 into benzene, the extract having an absorption maximum at 561 nm. The calibration graph prepared by the proposed procedure was linear over the range 0.020.5μgcm^-3 of nickel and passed through the origin. The apparent molar absorptivity is 1.35×10⁵dm³mol^-1cm^-1. A highly sensitive extraction-spectrophotometric method for the determination of nickel with 5-NPA-5-NPH is proposed and has been successfully applied to the determination of nickel in a tungsten steel sample.

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β-Cyclodextrin has been immobilized on silica gel via a new spacer arm bearing no hydroxyl group. The D-and L-enantiomers of twelve dansylamino acids were separated on the resulting β-cyclodextrin stationary phase by HPLC. Compared with a β-cyclodextrin stationary phase bearing a hydroxyl group on its spacer arm, the new β-cyclodextrin stationary phase exhibited much higher enantioselectivity. The addition of urea (7M) to the eluent further enhanced the enantioselectivity of all dansyl derivatives except those of leucine, norleucine and phenylalanine.

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X-Ray fluorescence spectrochemical analysis of submarine sediments (Si, Ti, Al, Fe, Mn, Mg, Ca, K, P, Cr, Sr, Pb, Ni, Zn, Rb, Cu, Y, Mo) using bead samples of low dilution fusion has been performed. Two grams of sample was fused with 82.2% Li₂B₂O₇, 15% Li₂CO₃, 2% NaNO₃, and 0.8% NaI as a flux. The low dilution ratio {(sample+flux)/sample} of 1.2 was achieved by preoxidation of organic materials in the sediments by heating at 600°C for 5 min. Afterwards, the temperature was raised at 10501100°C for 7 min to permit the complete dissolution of sample in the flux. Limits of detection (3σ of background) were Mn 5.3/1.5, Cr 7.0/2.1, Sr 4.2/1.5, Pb 4.7/1.9, Ni 4.6/1.2, Zn 4.1/1.6, Cu 3.2/2.4, respectively. Exact dilution ratios were able to be obtained from ignition loss and ignition gain without any complicated calculation. The effect of coexisting elements was corrected with the theoretical alpha coefficient correction method. Accuracy (σ_d) was improved in comparison with uncorrected data. The analytical results of standard samples of Lake Sediment (JLk-1) and Stream Sediment (JSd-1) for the Geological Survey of Japan were in good agreement with the recommended values. Accuracy with the fundamental parameter correction (FP) method using one sediment standard sample was a little worse in the determination of trace elements, but the FP-method was adequate for rapid analysis. The proposed method was applied to the analysis of various submarine sediments and the analytical values were satisfactory.

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A porous cellulose tape coated with silica gel as an absorbent and impregnated with a processing solution which includes a fluorescent pH indicator (6, 9-dichloro-2-methoxyacridine), p-toluenesulfonic acid, glycerin and methanol is a highly sensitive means of detecting hydrogen chloride gas in air. When a sample containing hydrogen chloride was passed through the tape, the pH of the tape decreased. The fluorescence intensity was proportional to the concentration of hydrogen chloride gas at a constant sampling time and flow rate. The fluorescence intensities were measured at 375nm(λ_ex)and 510nm(λ_em). The detection limit was 0.05ppm for hydrogen chloride gas at a sampling time of 60 s and a flow rate of 400ml/min. No interference was observed from ethanol (1v/v%), trichloroethylene (1v/v%), acetone (1v/v%), carbon dioxide (4.9viv%), nitrogen dioxide (100ppm), sulfur dioxide (50ppm), acetic acid gas (24ppm), or hydrogen fluoride (10ppm).

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In order to determine impurities in titanium diboride by ICP-AES, a sample dissolution procedure using acids was examined. A 0.25 g titanium diboride powder sample was taken in a 100ml quartz beaker and 10ml of sulfuric acid (1+1) was added. After covering with a quartz watch-glass, 2ml of a mixture of nitric acid and hydrogen peroxide solution was added dropwise, and the beaker was left to stand with only occasional swirling at room temperature. After the reaction was completed, the mixture was boiled for several minutes on a sand bath, and further heated until sulfur trioxide fumes appeared after removing the watch-glass. After cooling, 20 to 30ml of distilled water was added, and the mixture was filtered. The small amount of residue on the filterpaper was ashed in a platinum crucible, and transferred into a Teflon pressure vessel with 3 ml of sulfuric acid (1+1), 1 ml of nitric acid and 2ml of hydrofluoric acid (1+9). The capped vessel was kept at 180°C for 16 h in a drying oven to dissolve the ashed residue. The filtrate and the residue solution were collected in a 100ml calibrated flask and diluted to the mark with distilled water, followed by ICP-AES measurement. For most elements, the values obtained by the proposed method were in good agreement with those obtained by the fusion method with sodium carbonate.

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