Mobile chemical analysis (MCA) systems were examined to improve on-site analysis. The MCAs developed were expected to be superior in rapidity and robustness to batch-wise methods in chemical analysis, as well as being less heavy and battery-driven, and to be able to measure multi-components in a system. Also, the system had better to be simple, and to be able to automate chemical analysis. In this work, the MCA systems were developed on the basis of both of a flow chemical analysis technique and a computer-controlled technique. The essential modules for assembling MCA systems were syringe pump modules, valve modules (switching- and selection-type) and solenoid pumps as well as valves modules. For controlling such pumps and valves, a lab-made software, so-called LMPro, was developed; it could control fifteen syringe pumps and valves, as well as fifteen solenoid pumps and valves. By using this software, almost all computer-controlled flow chemical analysis systems reported so far could be controlled; further, some new MCA systems could be developed by assembling such pump and valve modules. In the present work, several kinds of computer-controlled flow chemical analysis (CC-FCA) systems for MCA were examined by using software, LMPro ver.1-5. The CC-FCA systems assembled and examined were: a syringe-propelling flow injection analysis (SP-FIA) system, an air-walled SP-FIA (AW/SP-FIA) system, a sequential injection analysis (SIA) and SI-related systems, a merging zone-FIA (MZ-FIA) system, a simultaneous injection effective mixing flow analysis (SIEMA) system, a column pretreatment (Auto-Pret) system and so on. Such systems were controlled by the LMPro program without any problems. For multi-component analyses, a multi-channel absorptiometric detector with an RGB LED lamp was used. As model analytes, nitrite and nitrate ions, phosphate ion, ammonia and Cr(VI) ion were examined. Of the MCA systems examined, SP-FIA and AW/SP-FIA were favorably applied to a sensitive measurement, because of less Schlieren effect (SE). In SIA, MZ-FIA and SIEMA, SE was relatively large, and sometimes SE interfered with the measurement of low concentrations of analytes. A method for compensating SE was examined by using the similarity of SE between different wavelength.

This study focused on Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy (SEM-EDX) for the conventional determination of major elements contents in rock samples. The measured elements were Na₂O, MgO, Al₂O₃, SiO₂, K₂O, CaO, TiO₂, and Fe₂O₃. The appropriate preparation conditions were the sample grain size of less than 8.0 μm in median size, and an analysis area wider than 12.15 mm² in SEM-EDX. The analytical results indicated that the relative standard deviation of measured element content fell within almost 10 %. By comparing between the SEM-EDX and XRF analysis, SEM-EDX is quantifiable to be the relative standard error within 7.7 % (Na₂O), 8.6 % (MgO), 5.9 % (Al₂O₃), 1.9 % (SiO₂), 8.7 % (K₂O), 10.0 % (CaO), 15.9 % (TiO₂), 18.7 % (Fe₂O₃). The application of this method to a geological survey indicated that the constituent minerals in the strata were predictable by examining the relationship with the major elements contents. Sample screening preceding an accurate determination of the elements and minerals composition is of great concern, because many analytical data are used for understanding the geochemical features of the strata. The SEM-EDX method proposed herein enables the measurement of major elements and the prediction of constituent minerals in the strata, and thus can be used as a screening method prior to an accurate geochemical analysis.

A PC-controlled LED photometer utilizing a microcontroller Arduino UNO was fabricated, and the performance was evaluated. Monochromatic violet (peak or dominant wavelength of the emitting light, λ_p = 395 nm), blue (468), blue-green (500), green (520), yellow-green (573), yellow (592), orange (608), and red (630 and 660) LEDs were used as the light source. The intensity of the emitting light is controlled from PC through the USB communication interface and the digital/analog converter of the microcontroller. A phototransistor was used as a photo detector. The intensity data of the light passed through the sample is sent to a PC through the analog/digital converter of the microcontroller and is handled to calculate the absorbance, Abs. Abs was measured for several dye solutions. The values corresponded reasonably with the absorbance recorded by a conventional spectrophotometer at around the λ_p’s. When Abs < 1.4, the experimental errors were reasonably small, and the calibration curve characteristic between Abs and the sample concentration was as good as that determined by conventional spectrophotometer. The present photometer is compact and lightweight, and its power source voltage is supplied from PC through the USB interface. Therefore, the photometer would be conveniently used for in situ analysis.

We propose here two new quantitative analytical methods for the determination of total nitrogen in environmental water samples. Firstly, a downsized alkaline peroxodisulfate digestion procedure for total nitrogen was proposed. An aliquot of the digested sample (the supernatant liquid) was introduced into a flow injection analysis (FIA) system in which the chemistry relied on a diazotization/coupling reaction with a copperized cadmium reduction column. The amounts of sample and digestion solutions were reduced to one-tenth and one-fifth, respectively, compared with the present Japanese Industrial Standard (JIS) method. Furthermore the batchwise digestion procedure was able to treat not only clear (transparent) samples, but also samples including suspended solids so that various kinds of samples can be introduced into the subsequent FIA system. Secondly, we developed an on-line digestion FIA method for total nitrogen based on both of ultraviolet spectrophotometry of nitrate and the above mentioned diazotization spectrophotometry of nitrite. In the proposed FIA system equipped with both an ultraviolet and visible detectors, an injected sample solution was subject to on-line alkaline peroxodisulfate digestion, the absorbance of nitrate, itself, at 220 nm was measured, and then the absorbance of the azo dye at 540 nm was measured. In conclusion, the these two quantitative analytical methods were both applied to natural water analysis, and the analytical results were in good agreement with those obtained by the present JIS method.

Due to the fact that chloride ions on a steel material surface can cause corrosion, if the steel material is exposed to sea water, the chloride ion concentration can be examined to determine the extent of contamination. Generally, in such a contamination examination, a smear method (wiping method) has been used. However, there are several challenges, such as difficulties in preparing clean gauzes or the requirement of a long sampling time. For that reason, the paper patch sampling method using filter paper was explored since this method can easily perform sampling of a steel surface chloride ion on a site. Test pieces with surface chloride ions of a 10 mg m⁻² concentration were prepared, and the recovery rates of chloride ion by three types of filter paper were evaluated. The result shows that, in the best condition, filter paper can achieve an average of a 98 % collection rate. This method was applied to an evaluation process for surface chloride ion on steam turbine blade, and was able to obtain the same analysis result as when a conventional method was used while reducing the sampling time to 25 %.

These days, disasters have frequently occurred in Japan and destroyed houses. A large amount of building materials containing asbestos has also been discarded after every disaster. We established a detection and recognition method of asbestos at simple, rapid and low cost by selective dyeing of asbestos in waste building materials. The building debris collected at disaster areas was crushed to a size of 1 to 2 mm and its dirty parts were removed by treating them with 20 % formic acid. A few particles of the washed sample were taken on a filter paper and dried on a hot plate for 5 minutes, and then stained with dyes. Asbestos in building materials is chrysotile over 95 % that is positively charged. On the other hand, main component in building materials is calcite and negatively charged. Therefore, chrysotile was stained with anionic dyes, such as erythrosine or eosin; the main component in building materials was stained cationic dyes, such as methylene blue, rhodamine B or cationic porphyrins. For example, chrysotile was stained in pink by erythrosine and the main component in building debris was stained in blue by methylene blue. Therefore, chrysotile in the building debris was easily detected by a stereomicroscope ( × 45 times). Furthermore, erythrosine did not stain crocidolite and amosite, and methylene blue stained crocidolite and amosite in blue and not chrysotile. That made it possible to detect chrysotile in waste building materials in distinction from crocidolite and amosite. Glass wool, ceramic wool and rock wool used in building materials were not stained with both methylene blue and erythrosine.

A smart device such, as a smartphone on a tablet, is widely used worldwide, because of many functions with low cost. We reported on a smart device color analyzer consisting of original attachment and application software. This method is able to strongly reduce the analytical cost and size. Moreover, the analytical result was displayed to a map using GPS and a mapping function of smart device. However, the low sensitivity of this technique makes it difficult to determine low concentrations. On the other hand, homogeneous liquid-liquid extraction is an effective preconcentration method with a rapid and high concentration ratio because the analyte can be concentrated from a milliliter-scale sample to a microliter-scale extraction phase at a high concentration rate in a short period of time. Using this preconcentration, the sensitivity of colorimetry can be improved. Based on these findings, in this study, we developed an optional attachment for the smart device color analysis of a sedimented phase from homogeneous liquid-liquid extraction. The analytical performance of proposed method was evaluated. Using the extraction of the hexavalent chromium complex with diphenylcarbazide by a water/2-propanol/dimethyl phthalate system, the ppb level of hexavalent chromium could be determined. By comparing with conventional absorption spectrophotometry, the proposed method has satisfied analytical performance as a simple analysis.

In recent years, the adverse effects on water environments due to organic pollutant leakage during disasters have been concerning. Therefore, it is important to conduct an emergency environmental survey to measure the pollution quickly. In this study, a rapid target screening method for organic pollutants in water environments has been developed. We have combined a rapid pretreatment cartridge with a database for GC/MS, which can measure approximately 1000 organic compounds. A sample (50 mL) added to 5 g of NaCl was extracted with 2 mL of dichloromethane containing internal standard substances for 1 min. Thereafter, the dichloromethane was collected in a glass vial, and then applied to the GC/MS measurement. The tested recoveries of 75 pesticides, using purified water, as well as river and sea water, were at acceptable levels compared with the target recovery rates (50-150 %). The analysis time of the developed rapid screening method was shorter than that of the conventional solid phase extraction method and liquid-liquid extraction methods, and the total time required for our analytical procedure was approximately 70 min. We have developed a target screening method that is promising for applications in both emergency pollution surveying and environmental monitoring.

A clean-up procedure has been developed for a rapid screening method used to determine hydrophilic organic pollutants in soil by liquid chromatography/mass spectrometry (LC/MS). We focused on the composition of the acetonitrile/water solvent mixture (50/50, v/v %), and performed the separation of acetonitrile by salting out with NaCl. Additionally, the acetonitrile solution was cleaned up using a column of ENVI-Carb C. In this study, we conducted recovery tests spiking with mixed standards of 23 pesticides (water solubility; 1.2-58000 mg L⁻¹) for these procedures to optimize salting conditions and to evaluate the recovery rate performance. The optimal salting condition for 4 mL of acetonitrile/water (50/50, v/v %) was determined to be >0.6 g of NaCl. Furthermore, the recoveries of the targeted compound were 74–102 % and the relative standard deviations in the repeated experiments (n = 3) were within 6.6 %. We also performed recovery tests for all procedures of the screening including extraction The recoveries of all the compounds except for Thiram were 76–125 % and the relative standard deviations were within 7.0 % (n = 4). The total time required for preparing our screening was approximately 1 h. Therefore, the developed method is suitable for surveying hydrophilic organic pollutants in soil in emergencies, such as a chemical spills and earthquakes.

Analytical techniques are irreplaceable factors for the manufacturing of electronic components to ensure their reliability and performance, which also enhance and accelerate the research and development for new products. According to our management philosophy regarding the quality of our products, we have been conducting intermediate inspections among the manufacturing processes using various analytical methods to verify the quality of raw materials. It is one of the crucial missions for the analysis section in our company to develop techniques for reducing the lead time and the costs. In recent days, the on-site inspections in the factory that provide ease and safety of the operation with high accuracy are required to increase the productivity. In this report, we introduce our typical techniques, such as on-site inspections, namely, the ion electrode method for chlorine examination instead of IC and impurity analysis replacing ICP-OES with ED-XRF.