Trace elements in a vehicle exhaust particulates environmental reference material (NIES No. 8) prepared by the National Institute for Environmental Studies were determined by an instrumental neutron activation analysis method (INAA). The vehicle exhaust particulates samples (ca. 150-550mg) were irradiated by neutrons for a short time (30s) and a long time (5h) at Musashi Institute of Technology Research Reactor (MITRR). Samples were irradiated by two methods: namely, thermal neutron irradiation without cadmium filter and epithermal neutron irradiation with cadmium filter. Activated samples were measured by four methods: γ-ray spectrometry, anticoincidence counting, coincidence counting and low energy photon spectrometry using a planar Ge detector LEPS). Concentrations of 52 elements were determined by these irradiation and counting methods.

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Today, there exists a demand for analytical methods and procedures with absolute power of detection down to the pg-range for numerous elements in complex matrices. They should enable either to detect very low element concentrations in bulk samples or to acquire exact data on elemental distributions on the micro scale. With decreasing absolute amounts to be determined in real samples, detectability and reliability are in increasing discrepancy with the onsequence that analytical results become unreliable or wrong and thus very often particularly uneconomic. The fast evaluation of analysis results for lower and lower concentrations or amounts to be determined is limited by a rapid increase of systematic errors of a physical, but predominantly of a chemical nature. In the attempt, for instance, to properly derive concentrations from intensities, great difficulties are often encountered. This basic problem occurs at the ng-level and still far more for analyses at the pg-level. The solution of this analytical problem is not a general one but is obtained by special strategies in each individual case. In problem-orientated work involving extreme trace analyses, the reliability and economy of a procedure will therefore remain incalculable until it will be possible to recognize and eliminate the sources of systematic errors and to confirm the analytical results by independent procedures. The strategies leading to the best results for elemental determinations at ng-and pg-levels will be generally discussed and demonstrated by examples of the determination of Hg, Se, Tl and precious metals.

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Acylation of aminopropyl-bonded silica gel for liquid chromatography with acid chlorides was investigated in terms of the pore structure of silica gel and the molecular size of acylating agents. Three types of aminopropyl bonded silica gel with different pore sizes, 40, 60 and 100A, were acylated with various acid chlorides. Silica gel with larger pore size generally reacted with a larger amount of acid chloride than that with smaller pore size. This trend was more remarkable when acylating agents with larger molecular size were used. Thus, the density of ligand on the silica surface can be controlled by the combination of pore structure of silica gel and molecular size of acylating agents. Unreacted amino groups on silica surface after the acylation with stearoyl chloride could be made to react when benzoyl chloride, with a smaller molecular size, was used as a second acylating agent.

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An anomalous fluctuation of the refractive index has been observed in the aqueous sodium chloride solution of about 0.1mol/l NaCl. The latter value orresponds to the salt concentration of the human blood. The fluctuation is just the same as that in the former experiment on the solution of 0.55mol/l, which corresponds to the salt concentration of seawater. For the elucidation of the source of the fluctuation, measurements have been made on the mixtures of the heavy water and the normal water, where a similar anomalous fluctuation has been found to occur at the concentration in the range from 15 to 20% by volume. This finding and the results of the quantum chemical calculation allow the fluctuation of the 0.1mol/l NaCl solution to be attributed to the fact that the concentration produces an interface of two structurally different phases for the solution. It is noted that the anomalous fluctuations are not observed when the dissolved oxygen is removed from the solutions.

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Stability constants of complexes of hydronium ion with three crown ethers were determined by a solvent extraction method. By thermodynamic experiments on these complexes in 0.5mol dm^-3 hydrochloric acid at 25.0°C, the stability constants, ΔH°/(kJ mol^-1), and TΔS°/(kJ mol^-1) were determined to be 0.27, 44 and 40 (15-crown-5), 0.40, 62 and 60(18-crown-6) and 0.51, 71 and 70(dicyclohexyl-18-crown-6), respectively. The stability constant values decrease as follows: dicyclohexyl-18-crown-6>18-crown-6>15-crown-5. Thermodynamic studies show that formation of crown ether-hydronium ion complexes are not due to the contribution of the enthalpy term, but rather to that of the entropy term.

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In direct atomization of aluminum in a graphite-cup furnace, copper was inaccurately determined at high temperature(above 2000°C), because the sample occasionally spattered out of the furnace. When graphite powder with a grain size of below 44μm diameter was put into the furnace, spattering was prevented, copper being accurately determined. Sensitivity and precision were improved with increasing amount of the powder. Calibration curve for copper was constructed with peak area of absorption signal by using aluminum containing a known content of copper. The relative standard deviation ranged from 2.6 to 16%. The limit of detection was 0.18ng for copper. This value corresponds to 0.00001₈% of copper in 1mg of aluminum.

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Cadmium and copper-species from native lettuce plants were isolated and quantified after Ultra Turrax homogenization in buffer and subsequent ltracentrifugation and gel filtration of the cytosol. From the cytoplasma, a high molecular weight metal binding-protein (>75000g/mol) containing 55% of the cytoplasmic cadmium and 20% of the cytoplasmic copper and a low molecular weight metal binding-protein (3200g/mol) containing 45% of the cytoplasmic cadmium and 70% of the cytoplasmic copper were isolated. Beside these there were two more copper binding-proteins of about 57000 and 25000g/mol, containing only small percentage of copper. The solid fragments of the cell, containing 50% of the total cadmium and 20% of the total copper respectively were not further examined. A broad variation in the metal balance from plant to plant was observed.

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On the basis of a fact that zinc(II) forms 1:1 complex with 5, 10, 15, 20-tetrakis(4-sulfophenyl)porphine [T(4-SP)P] rapidly at room temperature by metal-substitution in the cadmium-T(4-SP)P complex in neutral medium containing imidazole, a simple and practical method for the determination of small amounts of zinc in high concentrations of cadmium has been developed. The Soret band of the zinc complex at 425nm are used for the determination, its apparent molar absorptivity being 4.45×10⁵l mol^-1 cm^-1. The method developed could successfully be applied to the determination of zinc in cadmium salts of guaranteed-reagent grade, without any preconcentration and prior separation. Further sensitization of the method by employing analogue derivative spectrophotometer is also described.

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The effects of major components of silicates (sodium, potassium, calcium, magnesium, iron, and aluminum) and other elements (rubidium, cesium, strontium, barium, and boron) on the determination of lithium, strontium, and barium in acidic rocks (GSJ-JG-1, GSJ-JG-1a and USGS-GSP-1) have been studied by ICP-AES. Lithium was successfully determined in the presence of 1mg/g of aluminum and 2mg/g of boric acid by ICP-AES after the rapid decomposition of the sample in a microwave oven. Analytical results for lithium agreed well with those obtained by the standard addition method and by flame emission spectrometry. Strontium and barium were also determined without any interference, and their analytical results also agreed well with the certified values. Total time for 10 sample analyses was less than 1.5h.

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Elements involved in humic acids extracted from marine sediments were determined by ICP emission spectrometry. Humic acids were extracted from sediments with 0.2M NaOH and precipitated with HCl below pH 2. The precipitate was redissolved into NaOH, filtered and reprecipitated with HCl. These procedures were repeated three times. After passed through an ion-exchange resin column, humic acid was obtained as acid type. Humic acid samples were digested with HNO₃ and HClO₄ and aqueous solutions were served to metal determination. Fe, Al, P and Cu were found in large amounts in marine humic acids. Commercially available Aldrich humic acid contains metals of one or two order of magnitude smaller concentration compared to marine humic acids. Metals in sediments were also determined and the ratio of metal association to humic acid was calculated. The large portion of Cu was found to bind with humic acid. Zn, Mo and Ni were also rich in the humic acid. The effect of HF wash on metal contents of humic acid was shown by the fact that the ash content and the amount of Al, Fe and Mg were remarkably decreased.

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The hollow cathode lamp-inductively coupled plasma-atomic fluorescence spectrometer system (Baird) has been evaluated for the measurement of Na, Cu, Ni, Ag, Fe, Al, Cr and Mg in a variety of organic solvents. Kerosene proved to be the best solvent. The system was evaluated for the effect of solution flow rate, oil content, O₂ flow rate, RF power and observation height for the measurement of those eight elements in a 2% oil-98% kerosene mixture. Analytical figures of merit, including detection limits, linear ranges of response, stability with time, and spectral interferences, were evaluated for the 8 elements present as metallorganic compounds. The analysis of several standard reference materials showed excellent agreement with the certified values.

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A flow injection Spectrophotometric method has been developed for the determination of manganese in silicate rocks with formaldoxime as a chromogenic reagent. A rock solution is prepared by fusion with a mixture of lithium carbonate and boric acid and subsequent dissolution of the cake in 1M hydrochloric acid. An aliquot of the sample solution is treated with hydrofluoric and perchloric acids and passed through a cellulose phosphate column to remove polyvalent cations like iron(III) and aluminum(III). A definite portion of the filtrate is injected into the flow system where the manganese-formaldoxime complex allows to be formed and monitored at 452nm. Nickel is masked with 2-aminoethanethiol by a merging zone technique. The flow injection analysis system permits throughput of 45 samples per hour. The relative standard deviations (n=10) for 0.5 and 2.0ppm manganese solutions are 0.80 and 0.33%, respectively. The procedure has been applied to a variety of standard silicate rocks of the U.S.Geological Survey and of the Geological Survey of Japan, yielding the results which are in satisfactory agreement with the recommended or reported values.

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A new procedure has been presented for gas chromatographic determination of mercaptans. In the method, aliphatic and aromatric mercaptans are converted to their pentafluorobenzyl derivatives with pentafluorobenzyl p-toluenesulfonate. The resulting derivatives are subsequently determined by gas chromatography with flame ionization detection. In the derivatization, tetra-n-amylammonium chloride is used as a phase transfer catalyst. The effects of the added base and of reaction time on the pentafluorobenzylation are discussed.

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Fluorescence of 8-anilinonaphthalene-1-sulfonate (ANS) was found to be enhanced by heparin-protamine complex. Heparin was found to bind with protamine electrostatically and the highest fluorescence was observed when the concentrations of sulfate groups of heparin and arginine moieties of protamine were equal. The increase in the fluorescence intensity of ANS was assumed to be caused by its interaction with the hydrophobic regions induced in the protamine molecule by the interaction with heparin. The phenomenon was applicable to the determination of heparin.

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Anionic surfactants in water were determined by a spectrophotometric flow injection technique coupled with solvent extraction. The ion associate which formed between an anionic surfactant and an cationic azo dye was extracted into an organic solvent and the absorbance was measured. The carrier was distilled water, and the reagent solution contained an cationic azo dye and sodium sulfate, the pH of which being adjusted to 5 with acetate buffer. A phase separator with a poly(tetrafluoroethylene) porous membrane (0.8μm pore size) was used to separate the organic phase. Six derivatives of cationic azo dyes and several extracting solvents were examined; a pair of 1-methyl-4-(4-diethylaminophenylazo)- pyridinium cation and chloroform turned out best. The sampling rate was 30 samples per hour. Calibration graphs were linear up to 2×10^-6M or 3×10^-5M of anionic surfactant when injection volume was 300 or 100μl, respectively. The relative standard deviation(n=10) was 1.5% for 300μl of 1×10^-6M sodium dodecylsulfate. The detection limit was as little as 1×10^-8M of anionic surfactant. Anionic surfactants in river water were determined satisfactorily.

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