The determination of ionic surfactants was carried out on the basis of ion association between ionic dyes and ionic surfactants in an aqueous medium. Three kinds of dyes (tetrabromophenolphthalein ethyl ester(TBPE), methyl orange analogues and nitrophenylazophenol analogues) were used as novel ion-association reagents. The ion-association constants between cationic surfactants (Q⁺) with dyes (D^-) and anionic surfactants (A^-) were obtained. It was found that the hydrophobic interaction plays an important role in the formation of stable ion associates. On the basis of the ion association accompanying a color change, the analytical methods for the determination of ionic surfactants, such as a batchwise spectrophotometric method, a flow-injection method and a photometric titration method, were developed in the presence of a small amount of nonionic surfactant in an aqueous medium. In particular, the photometric titration method was examined in detail. Titration curves could be simulated by using the ion-association constants of both ionic surfactants and indicators with a titrant, quaternary ammonium ion. By using the simulation method of the titration curves, an evaluation of the end-points and selection of the desirable titration conditions were possible. The ionic surfactants at concentrations of the 1 × 10^-6 M level can be determined by the photometric titration method. The proposed titration method was applied to several practical samples; the results were in good agreement with both the results of the JIS titration method (Epton method) and a solvent-extraction method with ethyl violet.

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Passive samplers for the determination of NO₂ and SO₂ in the ambient air of mountains were investigated and applied to a spatial analysis of air pollutants along the slope of Mt. Hiei. Yanagisawa-type samplers were used for determining the atmospheric NO₂. After they were exposed for 24 h, the absorbed NO₂ was measured colorimetrically by the Saltzman method. However, SO₂ samplers comprising an absorbent filter containing sodium carbonate solution were made and exposed for 20 days. The absorbed SO₂ was oxidized to SO₄^2- with a H₂O₂ solution and determined by ion chromatography. Samplers were set up in 13 locations at Mt. Hiei and also at an air-pollution monitoring station of Kyoto city. The relative standard deviation for NO₂ and SO₂ determinations by these gas samplers were 1.54.0% and 310%, respectively. The average concentration of atmospheric NO₂ at Mt. Hiei was about 7 ppb. The NO₂ concentration and its distribution along the slope of Mt. Hiei changed considerably both daily and seasonally. However, the concentration of atmospheric SO₂ at Mt. Hiei, with a mean value of about 3 ppb, was lower than that of NO₂, and scarcely changed.

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A simple and rapid method using HPLC has been developed for the determination of macrolide antibiotics, kitasamycin and josamycin in animal tissues. Kitasamycin comprises several components : leucomycin A₁, A₃A₉ and A₁₃. Josamycin is identical to leucomycin A₃. The drugs were separated on a Puresil 5C₁₈ column (150 × 4.6 mm i.d.) with 0.05 M phosphate buffer (pH 2.5)-acetonitrile (58 : 42) as the mobile phase at a flow rate of 0.5 ml/min, and detected at 232 nm with 0.04 AUFS. The drugs were extracted with 0.3% metaphosphoric acid-methanol (7 : 3), and the extracts were cleaned up on a Bond Elut SCX (500 mg) cartridge. The calibration graphs were rectilinear from 5 to 100 ng for kitasamycin and josamycin. The recoveries of the drugs from various animal tissues fortified at a level of 1.0 μg/g were 76.891.5% with high accuracy. The detection limits were 0.05 μg/g for both drugs. By selecting the proposed methods using HPLC, the individual components of kitasamycin are can be quantitatively determined with speed, ease and accuracy.

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The adsorption of various phosphorus oxoanions on titanium oxide treated with alginate was investigated by capillary-type isotachophoresis. The various phosphorus oxoacid anions such as orthophosphate (P₁), phosphite (P³), hypophosphite (P¹), diphosphate (P₂) and triphosphate (P₃) ions were separated at pH 4.0 with a 0.01 M histidine hydrochloride-0.075% triton X-100 mixture as the leading electrolyte and 0.01 M hexanoic acid as the terminating electrolyte. The PU (potential unit) value increased in the order P₃<P₂<P¹<P³<P₁. The calibration curves for P₁, P³ and P¹, P₂ and P₃ were linear in the range of 10120, 1080 and 1050 μmol, respectively. The relative standard deviation for the measured phosphorus oxoacid anions were less than 5% (n=5). The maximum amounts adsorbed on the titanium oxide treated with alginate (μmolg^-1)of P₁, P³, P¹, P₂ and P₃ by stirring (500 rpm)for 5 h (the amount of P¹ reached the maximum after 1.5 h and subsequently decreased little by little) at pH 1.6 were 320, 270, 180, 140 and 90, respectively.

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Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine elements in water samples containing an extract from plastic containers for blood transfusion and hyperalimentation. Many elements were detected from the water samples. The concentration patterns, consisting of each extract from the plastic containers, were different from each other. These findings suggest that the elemental concentrations of extracts from the plastic container should be regulated. In the Japanese Pharmacopoeia, the elemental concentrations in the extracts from the containers are not regulated. So far, only the contents of heavy metal (lead, cadmium and tin) in the materials constituting the containers are regulated.

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The oxygen-electrode method for evaluating uricase activity in a hair-color product containing an oxidation dye precursor has been developed. Uricase catalyzes the following reaction: uric acid + O₂+ 2H₂O→allantoin +CO₂+ H₂O₂. The proposed method for the uricase activity assay is based on a measurement of the rate of O₂ consumption. The rate constant (k) was determined by an analysis of [O₂] vs. t curves. This reaction was also found to be explained by the Michaelis-Menten equation. Accordingly, k vs. the dose of uricase plots gave a straight line in the range of 0.0451.59 units ml^-1. The determined values of k showed no influence upon the addition of p-phenylenediamine as an oxidation dye precursor. The proposed method was successfully applied to an evaluation of the uricase activity in a hair-color product.

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As is well known, greenhouse-effect gases causes serious global warming, and it is very important problem for the 21st century. The authors observed the greenhouse-effect of carbon dioxide, whose contribution ratio to warming is most high. Now the concentration of carbon dioxide is presently approximately 350 ppm, and is estimated to become 400 ppm in the year 2000. An absorption-fixation method was applied photosynthesis by Water Hyacinth an aquatic plant. Also, an apparatus was developed that can accurately measure the concentration of carbon dioxide. The authors suggest a plant-cultivating apparatus whose temperature, humidity and illumination can be controlled, and maintains the interior of the cultivating room at constant conditions, for growing Water Hyacinth. A continuous 24-hours measurement was carried out of carbon dioxide in the cultivating apparatus using a gas chromatograph with an auto sampler. We could accurately measure the carbon dioxide concentration in plant cultivating apparatus using this apparatus.

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In order to obtain a rapid and precise measurement of the dissolved antimony concentration in seawater and sediment pore water, a semi-automated apparatus using a hydride-generation technique with an atomic-absorption spectrophotmeter as a detector was developed. To a 50 ml sample, 5 ml of 12 M HCl and 0.3 ml of 5 M KI are added manually. After that, the following steps are automated. A 2% NaBH₄ solution is introduced into the sample by a rate of 1.5 ml/min for 6 min. Dissolved antimony is converted to stibine during this step. The stibine is trapped in a U-shaped glass column packed with chromosorb WAW-DMCS (3% OV-101) under liquid nitrogen. After 6 min the column is heated for 2 min to volatilize stibine, which is introduced into a heated quartz cuvette. Helium is used as a carrier gas; its rate is 100 ml/min. The detection limit using a 50 ml sample is 0.015 nM. The reproducibility of an analysis determined by replicate analyses of the same sample is within 5% (expressed as a relative standard deviation) by using a seawater sample spiked with 1 nM Sb (V).

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The reason for the yellowing of packed textiles under long-term storage is the formation of derivatives of an antioxidant (BHT) oxidized by nitrogen oxides (NO_x) in the air. The method used to analyze a yellowing material by HPLC and GC/MS was proposed for studying this mechanism. Yellowed textiles were analyzed by HPLC with the basic moving phase and GC/MS with a capillary column to detect yellowing substances. Although three yellowing substances were detected, 3, 3', 5, 5'-tetra-t-butyl-4, 4'-stilbene-quinone (TBSQ), which is the derivative of BHT oxidized by NO_x, was not detected. An unknown yellowing substance was detected in nylon textile. New mechanisms of yellowing should be investigated. The proposed method is suitable for studies of divers yellowed textile.

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Platinum and platinum-alloy crucibles for their losses on ignition and on fusion using various flux have been examined. Crucible made of nine different materials were used: pure Pt, platinum-alloys such as Pt and ZGS-processed material, Pt-Rh (5% and 10%), Pt-Ir (5% and 10%), Pt-Au (3% and 5%) and Pt-Pd (10%). After an ignition test at 1100°C for 100 hours, slight gains were observed for Pt-Rh (10% ) and Pt-Pd (10%) ; losses were observed for all other materials. Since the loss was especially large for the Pt-Ir crucible, it cannot keep a constant weight under intense heat of over 1100°C. A fusion test using only alkali carbonate showed the smallest loss for the Pt-Pd crucible. However, no significant differences in the loss were found among different materials when the test was performed with fusing mixture containing boric acid, or with rock samples added. A fusion test using alkali disulfate showed a somewhat lager loss for the Pt-Pd crucible compared with the other crucibles. As a whole, the fusion test with alkali carbonate resulted in greater losses compared with the fusion test with alkali disulfate. The Pt-Au crucible was found to be the best in terms leaving of melts, keeping its surface comparatively smooth after repeated tests.

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A selected-dissolution method was investigated in order to analyze a crystal-grain and grain-boundary phase in aluminium nitride which was used as a high thermal-conductivity substrate. Unreacted Y₂O₃ in the sample was dissolved by 1.5 M hydrochloric acid. A crystal in the residual sample after hydrochloric acid dissolution was dissolved by 2 M sodium hydroxide. The residue which was not dissolved by them was used to determine the grain-boundary phase. EDTA titration, acid-base titration, ICP-AES and X-ray diffraction were used to analyze the composition of the crystal-grain and grain-boundary phase. In the aluminium nitride, to which Y₂O₃ was added, two grain-boundary phases were constructed (Y₃Al₅O₁₂ and YAlO₃). Also, it was confirmed that they influence the thermal conductivity.

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A method for the determination of trace amounts of Al, Cr, Cu and W in silicon carbide by inductively coupled plasma mass spectrometry (ICP-MS) was investigated. Samples were digested with a mixture of 3 ml of H₂SO₄, 5 ml of HNO₃ and 10 ml of HF in high-pressure teflon vessels at 220°C for 12h. The HNO₃, HF and silicon matrices were removed by evaporation after digestion. The remaining sulfuric acid resulted in a dissolution of sampling cones, and the unstable extraction of analyte ions from the plasma when the spray chamber was cooled to -4°C. Erosion of the sampling cones was avoided by keeping the temperature of the spray chamber at 22°C, because a cooler spray chamber produced higher concentrations of sulfuric acid due to suppression of watervapor evolution. The analytical results obtained by the proposed method were in good agreement with those obtained by graphite-furnace AAS and ICP-AES. The detection limits for the analytes were less than 0.1 μg g^-1.

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Reverse-phase HPLC (RP-HPLC) for sub-ppb levels of Co (II), Ni (II), Cu (II) and Pd (II) in water samples has been studied using an on-line enrichment technique with ammonium pyrrolidinedithiocarbamate (PDC) as a complexing agent. When the metal-PDC complexes injected into the RP-HPLC system reached the top of the octadecylsilanized silica (ODS) column, the complexes did not travel in that column with water dissolving the complexes. The metal-PDC complexes were concentrated at the top of the ODS column, and were then resolved and detected by RP-HPLC with a multi-photometric detector using a mixture of acetonitrile and water as a mobile phase. These complexes had different absorption spectra with the kind of metal ion combined with PDC. A photo-diode array detector was therefore useful for an accurate spectrometric identification of the complexes. A sample solution containing less than 1 μg of those metal ions was taken into a 25 ml volumetric flask. After the pH of the solution was adjusted to about 7, a buffer solution (pH : 6.0) and 2 ml of a 1 × 10^-4 M PDC solution were added to that flask to form metal-PDC complexes. After adding water to the mark of the volumetric flask, a 4 ml portion of the solution was injected into the RP-HPLC system. The composition of the mobile phase was as follows: 10 (0.1 M phosphate buffer, pH : 6.0) : 65 (acetonitrile) : 25 (water) (v/v). The absorbance was measured over the range of 240 to 360 nm. The flow rate of the mobile phase was 1 ml/min. In this procedure, the injection volume was not influenced over the range of 20μl to 4 ml. The observed detection limits of Co (II), Ni (II), Cu (II) and Pd (II) at S/N=3 were 3 ng, respectively. Since the volume of the sample solution containing those metal ions was 20 ml, they corresponded to 0.15 ppb. The relative standard deviations of four measurements for the determination of those metals in well-, river- and waste-water samples were in the range of 1.48 to 5.45%.

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The redox potential of a system involving metal ions has been modified by the complexation of metal ions with a suitable ligand. This phenomenon has a potential capacity for the development of novel redox systems which are applicable to quantitative analyses. Potentiometric titrations of vanadium(IV) with iron(III), cobalt(II) with vanadium(V) and cobalt(II) with chromium(VI) are possible in the presence of 1, 10-phenanthroline (phen) or 2, 2'bipyridine. A new spectrophotometric FIA determination of iron(II) has been presented based on the redox reaction of copper(II) with iron(II) in the presence of bathocuproinedisulfonate together with diphosphate.A new-type procedure for the spectrophotometric FIA method was developed for the simultaneous determination of redox couples of vanadium(V)/vanadium(IV) and quinone/hydroquinone based on this principle. The procedure was adapted to simultaneous determinations of iron(III) and vanadium(V) and of iron(III) and chromium(VI). It has been found that the redox reaction of cysteine with iron(III) in the presence of phen is accelerated by the addition of copper(II). A spectrophotometric FIA determination of cysteine was proposed based on the accelerating effect of copper(II) on the rate of the redox reaction. A spectrophotometric reverse FIA (rFIA) determination of complexing agents such as aminopolycarboxylic acids and polyphosphates was developed based on the redox reaction of copper(II) with iron(II) in the presence of neocuproine. By using this rFIA system, a new procedure for estimating the complexing capacity in natural water was developed.

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