In the environmental trace analysis of water samples, it is one of the most important problems to prepare the reliable standard solutions of extremely dilute concentration comparable to the samples. In the present study, standard solutions of 50 ppb Cr(III) ions were prepared and stored in containers of glass and polyethylene. During the storage in both the containers, exponential decrease of Cr(III) was observed, and after ten days the degree of decrease attained to a constant value. Effect of pH on the adsorption of Cr(III) was also examined in a pH ranges from 1 to 13. In the case of glass container adsorption of Cr(III) occurred between pH 4 and 12, while it occurred between pH 5 and 11 in the case of polyethylene container. The maximum of adsorption appeared at a pH around 7.5 in both the cases. These results suggest that chemical species of Cr(III) adsorbed would be Cr(OH)₂(H₂O)₄⁺. By taking the above facts into consideration, suitable media for stabilizing the standard solutions of Cr(III) were examined. As a result, it is confirmed that the stand-ard solutions are stabilized by the addition of nitric acid to adjust pH below 3 and/or by the presence of 10^-4 M of EDTA or 10^-3 M of phosphate ions.

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A simple and selective method is proposed for the determination of alkylbenzenesulfonate (LAS) in water by high-performance liquid chromatography (HPLC). LAS was extracted with methyl isobutyl ketone (MIBK) from aqueous media quantitatively in the presence of sodium chloride. LAS in MIBK extract was determined by HPLC without other pre-treatment. A Nippon bunko SIL C-18 was used as a stationary phase (stainless steel column 4.6 mm i.d.×250 mm) and a 80 % ethanol solution was used as an eluent (flow rate, 1 ml/min; column temperature, ambient; detector, UV 225 nm). The peak of LAS was very sharp and separated completely from that of MIBK. Homologous LAS were separated by using a Unicil C-18 column (4.6 mm i.d.×250 mm) as a stationary phase and a mixture of 0.005 M tetrabutylammonium bromide and 0.001 M disodium hydrogenphosphate in 80 % ethanol solution was used as an eluent (flowrate, 1.5 ml/min). The effect of pH and sodium chloride concentration on the determination of LAS were examined. The recommended conditions are as follows:pH, higher than 9 (adjust the pH with sodium hydroxide solution) ; sodium chloride concentration, 1 w/v %; final volume of aqous phas, 100 ml; MIBK, 10 ml. The calibration curve for sodium dodecylbenzenesulfonate was linear within a range of (0.0050.2) p.g/5μl (injection volume of MIBK layer). The coefficient of variation was 2.3 % for 0.025 μg of LAS. The recovery of LAS from river water and sewage water were (90104) % and (8187) %, respectively.

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Separation of sixteen rare earth elements by high performance liquid chromatography was studied. A 0.4 M α-hydroxy-iso-butanoic acid (a-HIBA) solution was used as eluent and the eluted metal ions were detected with a coulometric detector. It was observed that the pH-gradient elution was effective for rapid separation. Good separation was achieved by the pH-gradient elution of initial pH 3.50 and final pH 7.00. The increase of column temperature improved the column efficiency. Sixteen rare earth elements could be separated each other in about 75 min using strong cation exchange resin (Hitachi # 2611) column, a 0.4 M α-HIBA solution and a pH gradient method. Resolutions of 16 rare earths were between 1.38 and 3.85, only dysprosium-yttrium being 0.91.

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Selenium in herb plants was determined by neutronactivation analysis using a coincidence counting method with a correlation of ⁷⁵Se gamma-rays energies between a NaI (T1) detector and a Ge(Li) detector. Each freeze-dried herb plants sample (c.a. 250 mg) was irradiated for 5 h at Musashi Institute of Technology Research Reactor in a thermal flux, 3.2 × 10¹² n cm^-2 sec^-1. After about (26) weeks from the irradiation, gamma-rays were counted by means of the coincidence counting method with a Ge(Li) detector and a NaI (T1) detector. In this counting method, the background around the photopeak of ⁷⁵Se-265 keV could be reduced to one twentieth: accordingly the detection limit of selenium could be improved by a factor of four when compared with that by the conventional counting method. For examing the accuracy and the reproducibility of this method, selenium contained in Bovine Liver and Orchard Leaves (NBS) were determined, and the content of selenium was in good agreement with the certified value. The selenium contents of five kinds of galic and onion samples were found to be in range of (0.020.31)μg/g dry weight and in range of (0.020.05) μg/g dry weight, respectively. These values were also in good agreement with fluorometry results. The selenium contents of other herb plants were less than 0.1μg/g.

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Some different types of miniaturized polymer membrane electrodes (PMEs) for chloride ion were constructed by the use of epoxy matrix membrane. The PME of the best characteristics consists of a copper wire and three coating layers of silver paste of epoxy matrix type, silver chloride and epoxy matrix incorporating about 45 wt % of an ion exchanger solution. The most suitable ion exchanger solution was 1-decanol containing 0.4 wt % of trioctylmethylammonium chloride. The thickness of coating layers were (0.20.3) mm at each layer and the electrode was about 1 mm outer diameter. The responses of the PME were Nernstian for (5×10^-54×10^-2) M chloride.The noise of the PME on electrode potential was ± 0.5 mV at the lower linear response range. The selectivity coefficients (K^pot_ij) of the PME for perchlorate and iodide were 1.3 and 1.1, respectively.

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Four kinds of the immobilized matrixes (Nylon 66 tube, Nylon 6 polymerized in glass capillary, whisker-walled glass capillary and controlled pore glass beads) were used for the fundamental consideration of the application to reaction detector and discussed about their characteristics. Triethyl oxonium tetrafluoroborate was used for O-alkylation of nylon tube and nylon was further reacted with 1, 6-diaminohexane as spacer. Glucose oxidase (GOD) and cholesterol oxidase (COD) were immobilized on the nylon through bismidate I. (Nylon 66, inner diameter φ: 0.2 mm, immobilized enzyme: GOD, activity: 0.53 μmol min^-1 m^-1), (Nylon 66, φ : 0.2 mm, COD, 0.43 μmol min^-1 m^-1), (Nylon 6 polymerized in glass capillary, φ: 0.7 mm, GOD, 1.68 μmol min^-1 m^-1). Whisker-walled glass capillary which was made by fluoroether was reacted with dimethyl dichloro silane. COD was immobilized on it through ethylenediamine and glutalaldehyde. (Whisker-walled glass capillary, φ : 0.26 mm, COD, 3.37 μmol min^-1 m^-1), (glass beads, GOD, 40.5 μmol min^-1 g^-1), (glass beads, COD, 31.9μmol min^-1 g^-1). The activities of these immobilized enzyme were measured by 4-aminoantipyrinephenol method in the presence of peroxidase. As the results, nylon tube supported enzyme had lower activity compared with other glass matrixes, but it was easier to handle than glass capillary column. Whisker-walled glass capillary column was a good matrix for immobilized enzyme as well as controlled pore glass beads because of the large surface area and of the high enzyme activity. A glass capillary (40 cm) on which enzyme was immobilized showed reduced band broadening compared with 10 cm bed reactor of glass beads packed teflon tube (φ: 1.5 mm)

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To optimize the conditions of liquid-solid chromatographic system, it is necessary to examine systematically the retention behavior of given samples. In this paper, correlation between logarithm of capacity ratio (k') and logarithm of molar concentration of strong eluent (X_s) on silica gel-binary solvent system was quantitatively investigated. Sapogenins and its derivatives from panax ginseng were used as model samples. Experiments of HPLC were performed using a S.P. 024 pump (JASCO), VL 611 injector (JASCO), RI detector (LDC), and stainless steel column (250 mm × 4 mm i.d.) packed with spherical shaped silica gel [LC-5K(Wako pure chem.)] as adsorbent. Binary solvent consisted of diluent [hexane (O), benzene (P), dichloromethane (N)] and strongly eluting solvent [diethyl ether (B₁), ethyl acetate (B₂), acetone (B₃), tetrahydrofuran (B₄), dioxan (B₅), 2-propanol (AB)]. All experimental results were obtained at ambient temp {(23±2) °C} and humidity {(60±5) %}. Panaxadiol was eluted faster than panaxatriol. Benzoate was eluted faster than acetate, and the latter faster than free sapogenin. The order of strengthof the eluents were found to be B₁<B₂<B₄≅B₅<B₃< AB, and the diluents O<P<N.

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Epidemiological works in Greenland Eskimos indicated that ω-3 polyunsaturated fatty acids, especially ω-3 eicosapentaenoic acid (C_20:5) have a potential anti-thrombotic and anti-atherosclerotic actions. For the determination of polyunsaturated fatty acids in total lipids in plasma, we established a new method using a gas chromatograph equipped with a glass capillary column. Total lipids were extracted from 0.4 ml of plasma using the method by Folch et al. After hydrolysis with KOH, methyl esters of fatty acids were prepared with BF₃ methanol. C_23:0 was used as an internal standard. The esters were analyzed by gas chromatography using a Hitachi 063 gas chromatograph equipped with a hydrogen flame ionization detector. A glass column of 40 m × 0.3 mm φ, coated with diethylene glycol succinate (DEGS), was used. The flow rate of carrier gas (nitrogen) was 25 ml/min. The injection port was kept at 350° and the detector cell at 220°. All the esters were chromatographed at 180° column temperature. Each methyl esters was indentified by the authentic fatty acid methyl esters. Reproducibility (cv value) of the determination of arachidonic acid (C_20:4), C_20:5, and docosahexaenoic acid (C_22:6) by this method were 3.8 %, 4.4 % and 2.3 %, respectively. Recoveries for methyl esters of C_20:4, C_20:5 and C_22:6 were 105.8 %, 112.0 % and 103.3 % respectively. For the quantitative analysis of fatty acids methyl esters, standard curves for C_20:4, C_20:5 and C_22:6 were obtained using authentic samples. As an example of clinical application of this method, fatty acid composition of total plasma lipid was determined for healthy volunteers before and after taking C_20:5 rich fish diet. A significant increase in plasma C_20:5 content was observed. This new method will be useful for its high reliability.

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The silica gel-immobilized imminoacetate (SIA) was prepared by treating silica gel with N-(2-aminoethyl)-γ-aminopropyltrimethoxysilane, and then subsequently with monochloroacetate. The resulting SIA was found effective for the selective preconcentration of metal ions, especially for that of Cu(II). The sample solution was passed through the column packed with SIA at a flow rate of 10 ml min^-1. Cu(II) was eluted with 3 M hydrochloric acid at a flow rate of 4.0 ml min^-1, then being amperometrically detected by the glassy carbon flow-through electrode. Various foreign substances as high as 0.05 M, did not interfer the recovery of trace Cu(II). The proposed method was applied to the determination of Cu(II) at ng ml^-1 concentration lebel in the synthetic sea water. The lower detection limit was 0.1 ng ml^-1 for a 20 ml sample, when the signal to noise ratio was 3. The determination of Cu(II) in water could be performed at a 10 samples h^-1 rate with satisfactory precision.

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Ion exchange chromatography with conductivity detector has been studied theoretically. In either case, with or without suppressor column, the electrolyte concentration of eluent is to be much lower than that used in the usual ion exchange technique. Accordingly, use of low capacity exchanger is essential to achieve the detection. Theoretical calculations by plate theory revealed that well-known relations among several parameters for the partition chromatography hold well even in the present, extraordinary condition. Relation between the conductivity change of the effluent and sample amounts injected is derived, allowing the detectability of ions to be estimated easily. With a high-sensitive conductivity meter, about 10^-9 mol or less of common ions is expected to be determined without suppressor column.

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In the presence of lanthanum{La(III)} and cetyltrimethylammonium chloride (CTAC), thorium {Th(IV)} complex with 3, 4, 5, 6-tetrachlorogallein (T.Cl. Gall.) was stable, and formed a solvent extractable ternary complex in butanol. The absorbance increased slightly and the color development time could be shortend by addition of La(III) and CTAC. The reaction was applied to a sensitive spectrophotometric determination of Th(IV). The ternary complex had an absorption maximum at 660 nm in the organic layer. The optimum pH range for the extraction was from 4.3 to 5.5. Beer's law holds for 017 μg Th(IV) in 10 ml of the organic phase. The sensitivity of the method was 0.0023 μg/cm² for Th(IV) at an absorbance of 0.001 and the wavelength of 650 nm. The recommended analytical procedure as follows : Up to 17 μg of Th(IV) was placed in a 50 ml of separating funnel to which were added 0.5 ml of 5.0 × 10²-4 M La(III) solution, 2.0 ml of 1.0 × 10^-2 M CTAC solution and 1.5 ml of 1.0 × 10^-3 M T.Cl.Gall. solution, and the pH of the solution was adjusted to 4.35.5 by the addition of 2.0 ml of Walpole acetate buffer solution, and then the solution was diluted to 20 ml with deionized water. The complex was extracted with 10 ml of butanol, the organic layer was taken out and separated with filtration. The absorbance of the T.Cl.Gall.-La(III)-Th(IV) solution was measured at 650 nm against T.Cl.Gall.-La(III) solution. The effect of diverse ions on the determination of Th(IV) was examined. The molar ratio of Th(IV) to T.Cl.Gall. of the complex was estimated to be 1:2 by means of the molar ratio method.

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A microcomputer aided data acquisition system for flow injection analysis was constructed and applied to fluorophotometric determination of gallium with lumogallion. The sample was injected into a stream of a lumogallion solution (lumogallion; 2 × 10^-4 M) and mixed with a stream of the nonionic surfactant polyethylene glycol monolauryl ether (PGME, 3 percent). The fluorescence signal was accepted by a microcomputer through an analog-input-output interface. The data was processed and displayed on a CRT and a printer. The constructed system enables a graphic display of an analytical curve by a plotter. Agreement of the observed data with a calculated linear analytical curve by a least square fit was excellent. The methods based on the measurement of peak height and peak area yielded no appreciable difference.

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A part of phenol groups in the strongly alkaline catalyst phenol resole resin (PFR) exists as a form of sodium phenoxides which makes the resin hardly soluble in tetrahydrofuran (THF). In the present method, sodium phenoxides in PFR were converted to phenols with a weak cation exchange resin, to make the resin soluble in the solvent. About 300 mg of PFR was dissolved in 0.5 ml of methanol, then thesample solution was passed through the open column packed with 4 ml of a weak cation exchange resin, Amberlite IRC-50 which is one of the carboxylic acid type cation exchangers. The eluate was introduced directly into 9 ml of THF in 50 ml flask. Finally, the cation exchange resin was eluted with 0.5 ml of methanol. 300μl of the eluate was injected into chromatograph without delay. Analytical conditions were as follows: apparatus; Toyo Soda HLC-801A, column; Toyo Soda TSK-GEL, G-3000H₈, G-2000H₈, X2, G-1000H₈, eluting solvent; THF, flow rate; 1 ml/min, detector; differential refractometer. It seemed that the influence of this procedure on the digree of condensation of PFR was fairly as small as the direct neutralization method of PFR with 2N acetic acid. However, the latter method produces sodium acetate, which gives an unfavourable effect on the column packing materials.

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Fluoride ion interferes with the spectrophotometric determination of titanium by hydrogen peroxide. This interference can generally be avoided by fuming the sample with sulfuric acid. Instead of this fuming, boric acid could also be used as the masking agent for the fluoride ion. A method for the determination of titanium in Nb-Ti, Nb-Ta-Ti, Fe-Ti and Cu-Ti alloys by using boric acid as the masking agent for the fluoride ion has been presented. When an amount of 1024 mg of titanium is contained in the final solution, the absorbance is measured by differential spectrophotometry against a reference solution containing 10 or 20 mg of titanium. Procedure 1: 0.2 g of titanium alloy containing neither niobium nor tantalum is dissolved in 5 ml of HNO₃ (30.5 %) and 2 ml of HF (46.5 %). After addition of a 40 ml portion of saturated boric acid solution, the solution is diluted to 100 ml with water. To a 20 ml aliquot of this solution, a 20 ml portion of H₃PO₄ (42.5 %) and a 1 ml portion of H₂O₂ (30 %) are added and the whole is diluted to 100 ml with water. The absorbance of the final solution is measured at 400 nm. Procedure 2: 0.2 g of titanium alloy containing niobium or tantalum is dissolved in 5 ml of HNO₃ (30.5 %) and 2 ml of HF (46.5 %). After addition of a 40 ml portion of saturated boric acid solution, the solution is put into a volumetric flask containing 1 ml of H₂O₂ (30 %) and diluted to 100 ml with water. To a 20 ml aliquot of this solution, a 20 ml portion of H₂SO₄ (47.5 %) and a 0.8 ml portion of H₂O₂ (30 %) are added and the whole is diluted to 100 ml with water. The absorbance of the final solution is measured at 400 nm.

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We report a sensitive fluorophotometric enzyme immunoassay (EIA) for measuring thyroxine (T₄) in dried blood samples on filter paper. Anti-T₄ IgG (rabbit) and the T₄-horseradish peroxidase conjugate of the Enzymun Test T₄ (Boehringer) were used. Bound and free fractions of the enzyme conjugate were separated by the antibody solid phase method, using anti-T₄ IgG-coated bead. The enzyme activity of the bound fraction was determined fluorophotometrically at excitation and emission wavelengths of 320 and 405 nm, respectively, using 3-(p-hydroxyphenyl)-propionic acid and hydrogen peroxide as substrate. Standard curves between 1.7 and 22μg T₄/dl were prepared from T₄ standards of dried blood spots. The intra- and inter-assay coefficients were 4.9-13.7% and 13.7-19.5%, respectively. The present EIA method was used in preliminary mass-screening tests for T₄.

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Bilirubin diglucuronide was purified from pig gallbladder bile. All lipids except bile acids were removed by phase separation with acetone, petroleum ether and ammonium sulfate. Bile acids were removed using active charcoal and an anhydrous solvent. Bilirubin diglucuronide was extracted with pyridine from charcoal. Further purification was made using a Sephadex LH20 column and methanol as an eluent. Purities of the product averaged 90 % and yields were about 6 %.

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A simple and systematic determination method was developed for 11 kinds of organic polybasic acids (OPBA) and their salts contained in various foods. Outline of the procedure is as follows: organic polybasic acids and their salts were extracted with water from sample, purified by ion-exchange column, prepared their derivatives with TMS (trimethyl silylation) reagent and then determined by gas liquid chromatography. Recoveries of them at 0.5 mg/g spikage levels in juice, jam and edible ice were within the range of 72.9-101.8%. Detection limit by this method was 0.01 mg/g and it takes only two hours for this whole procedures. The reconfirmation of them contained in some foods was carried out by thin layer chromatography.

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A sensitive, rapid and simple method for the spectrophotometric determination of papaverine based on the coloration due to the formation of an associated complex with o-hydroxyhydroquinonephthalein (Qn.Ph.), uranium(VI) and papaverine was studied. This method could be used in the concentration range of 085 μg/10 ml of papaverine. HCl where the sensitivity was 0.008 μg/cm² for papaverine.HCl for an absorbance of 0.001 at 550 nm, and was applied to the determination of papaverine.HCl in pharmaceuticals.

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To improve the sensitivities in UHF plasma torch atomic emission spectrometry, the sample nebulization process was modified. Conventional pneumatic nebulizers differed in their sample uptake rates; the sensitivities therefore varied with nebulizers. The sensitivities achieved by using the laboratory-built ultrasonic nebulizer varied with transducer power and plasma gas flow rate. Compared with the ordinary conditions (plasma gas flow: 3-4 1/min; conventional pneumatic nebulizer), the relative net intensities were increased from 1.3 to 7.6 fold for 7 elements at plasma gas flow of only 1.0 1/min using the ultrasonic nebulizer. The sample introduction to ultrasonic nebulizer, the sample removal from ultrasonic nebulizer, and cleaning the cell were made easily by using a reversible peristaltic pump.

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A modified gas chromatographic procedure is described for the separation of mixtures of saturated and unsaturated higher fatty acids having the same carbon number. On a 2% OV-17 column, the chromatogram of mixtures of stearic acid (18:0) and oleic acid (18:1) treated with iodine and iodine trichloride (I₂-ICl₃) in acetic acid at 20°C for 1 h showed better separation than that of those non-treated acids. The reaction product of oleic acid and I₂-ICl₃ solution was identified as stearolic acid by gas-liquid chromatography and mass spectrometry. The proposed method was also applied to the separation of palmitic (16:0) and palmitoleic acid (16:1).

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