Phenoxy- and pyridyloxypropinates have been known as selective herbicides. In the course of extensive investigation on this series with various condensed heterocyclic moieties, we have found among the guinoxalines some promising compounds to replace phenyl or pyridyl, which show excellent hervicidal activities against grass weeds. Among them, ispecially quizalofop-ehyl (Code No. NC-302) showed a potent herbicidal activity, so that it has been commercialized as a novel post-emergence herbicide. The quinoxaline moiety of quizalofop-ethyl, whose economical synthesis was one of the most important problems on the commercialization of this compound and has been intensively researched, is now able to be synthesized from low-priced raw materials economically. Quizalofop-ethyl has an asymmetric carbon atom, so it exists as a mixture of two antipodes. Active ingredient of this compound depends upon (R)-(+) isomer, which is twice as active as the racemate. (R)-(+) isomer can be stereoselectively synthesized from a chiral compound on retaining its chirality. Furthermore, there are two crystal fomrs of (R)-(+) isomer, while the rasemate shows only one crystal form. The discovery of this effective fractional crystallization of (R)-(+) isomer has enabled its commercialization. In this paper, the economical syntheses of chiral quizalofopethyl and its important intermediate chiral ethyl 2-(4-hydorxyphenoxy)propionate are described in detail.

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The carrier effects on the catalytic activity and the physical properties of supported palladium catalysts were investigated. The catalytic activity was evaluated by hydrogenation of benzene and physical properties of catalysts were probed with CO pulse method, transmission electron microscopy (TEM), electron probe microanalysis (EPMA), temperature programed reduction (TPR) and temperature programed desorption (TPD). The Pd/Al₂O₃catalysts were prepared by the adsorption method using dilute HCl solution (0.1 M to 1.0 M)of PdCl₂ and the Pd/SiO₂ catalysts by the ion exchange method using aqueous am monia solution of PdCl₂. The Pd/Al₂0₃ catalyst calcined at 500°C showed high activity and high dispersion, while th e Pd/SiO₂ catalyst calcined at 200°C exhibited highest activity and high dispersion. However, the catalytic activity and the palladium surface area of the Pd/SiO₂ catalyst decreased with the increased of the calcination temperature. The specific catalytic activity of Pd/Al₂O₃was roughly three times as high as that of Pd/SiO₂. The strong interaction between metal and support and a large amount of adosrbed hydrogen were revealed by TPR and TPD measurements in the case of Pd/Al₂O₃ catalyst. Palladium oxide formed on SiO₂ was easily reduced with hydrogen even at room temperature just as unsupported palladium oxide and the formation of palladium hydride was confirmed by TPR measurements. The nature of active sites produced on both supports was discussed from the stndpoint of carrier effects.

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Desulfurization capacities of 17 kinds of active carbon fibers (ACF) made from polyacrylonitrile (PAN), phenol resin, cellulose and pitch were studied by measuring the adsorption of SO₂ (1000 ppm) in a model flue gas (O₂ 5%, H₂O 10% and N₂) at 100-180°C using a flo w reactor with a fixed chopped fiber bed. Two kinds of PAN-ACF, FE-300 and FE-200, exhibited the highest activities among ACFs when the periods until the SO₂ break-through were compared. FE-300 could adsorb 7 x 10^-3 mol of SO₂/g ACF before its break-through which is 20 times those of other ACFs. The influences of adsorption condition (such as concentrations of components in the flue gas, W/F and adsorption temperature) on the capacity and desorption profiles of adsorbed SO₂ suggest that SO2 is adsorbed as sulfuric acid after the oxidation on ACF and that the adsorption capacity of ACF determines its capacity through the rapid adsorption of SO₂ into the pores on the fibrous surface where SO₂ is early oxidized into H₂SO₄. Surface functional groups of ACF as well as its pore size distribution may define its adsorption capacity in the presence of H₂O.

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Spinel(MgAl₂O₄) powders were prepared by the homogeneous precipitation method from the aqueous solutions of nitrates or sulfates mixture of aluminum and magnesium using urea. Precipitation was studied under [A1₃₊]=0.1 mol⋅dm_-3, [Mg₂₊]=0.05-0.2 mol⋅dm_-3, [urea] =1.8 mol⋅dm_-3 and at 90°C. The precipitation occurred in stepwise : Al₂O₃ hydrate precipitated at first and then MgO component deposited gradually (Fig.3). Precipitates with spine'composition obtained from the nitrate solution consisted of pseudo-boehmite and Mg-Al double hydroxide (Figs.4, 5). From the sulfate solution, MgO hydrate deposited on Al203hydrate particles (Figs.6, 7). On heating above 800°C for 1 h in air, both precipitates became spinel phase (Fig.8), indicating the higher reactivity of both components in the present powders than that in the powder mixture of MgO and Al₂O₃.

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Cordierite (2MgO⋅2Al₂O₃⋅5SiO₂) gel was prepared from ( 1 ) the Mg-Al-Si complex alkoxide synthesized by reactions of individual alkoxides. The gel structure and change during heat treatment were investigated by XRD and FT-IR spectroscopy, and compared with those prepared by ( 2 ) the hydrolysis of tetraethoxysilane with the crystallization water of Mg and Al nitrate hydrates and ( 3 ) the mixing of individual sols. There were major differeces in IR absorption bands due to Si-0 stretching vibration (Fig.2) and crystallization behavior (Table 1). In the gel derived from the complex alkoxide, the Si-0stretching band shifted to a frequency lower than that in silica gel owing to the introduction of Al into the silica network (Fig.2). It was possible to crystallize the complex alkoxidederived gel to μ- and α-cordierite at 900 and 1050°C, respectively, those crystallization temperatures being lower than those in methods (2) and ( 3 ) (Table 1). Neither the crystalline phase except cordierite nor the residual amorphous phase could be traced by XRD or IR spectroscopy (Table 1, Fig.4). The introduction of Al into the silica network is thus showed to affect the crystallization behavior of cordierite gels.

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The chemical composition of Recent carbonate sediments in Abu Dhabi sabkha was studied to estimate the depositional environment of the dolomites below the quartz sand layer (Fig.3). Sabkha is supratidal coastal plain, where carbonate minerals including protodolomite have been formed. The sampling locations are shown in Figs1-3. Strontium, sulfate and fluoride ions are enriched in Recent sabkha carbonate sediments relative to Pleistocene Mubarras shoal carbonates which have been formed under normal marine environments. X-ray diffraction analysis reveals that these minor elements are present as sparingly soluble minerals (celestite, gypsum, anhydrite and probably fluorite). On the contrary, PO₄ is depleted in the sabkha sediments relative to the shoal ones. The low PO₄ concentration may be attributable to the fact that the sabkha sediments contain only small amounts of high Mg-calcite which is a main P-bearing mineral among carbonate sediments. The good correlations between PO₄, and SiO₂, Al or Fe in the sabkha sediments suggest that P is derived from detrital silicate minerals (Table 4 and Fig.6). The behavior of these elements in underlying dolomites is geochemically similar to those in the Recent sabkha sediment, indicating the dolomites were formed under similar environments to the Recent sabkha. The Recent sabkha and the Pleistocene shoal dolomites are protodolomites with the (104)lattice spacings of 0.2894-0.2913Å, whereas underlying dolomites have ordered structure and stoichiometric compositions (Table 7). The dolomites may be formed before the Middle Pleistocene.

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The contents of 27 elements (Al, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, Hf, La, Mg, Mn, Mo, Nb, Ni, P, Pb, Sc, Sr, Ta, Ti, V, W, Y, Zn and Zr) in the 5-9 tissues of four ascidians (Halocynthia roretzi, Styela plicata, Pyura vittata and Phallusia mammillata)were semiquatitatively determined by inductively coupled plasma emission spectrometry after pretreatment including the dissection and the digestion (Figs.1, 2). The two kinds of plankton (or necton) were also analyzed by the same procedure as the tissues of ascidians. In the tissues of H. roretzi, S. plicata and P. vittata, no concentrated elements such as V. Nb and Ta were found, while vanadium was concentrated in the range of 190-810 μg/g dry weight in the blood, liver and digestive tract of P. mammillata (Table 5). Before the analysis of ascidians, the accuracy and precision of the analytical procedure were checked by employing the certified reference material (NIES No.6 Mussel) for marine animals prepared by National Institute for Environmental Studies. Though the analysis of Cr and Co had some problems, it was verified that the method was good enough for the 12 elements (Al, Ca, Cd, Cu, Fe, Mg, Mn, Ni, P, Pb, Sr and Zn) to be semiquantitatively determined. In particular the analysis was performed for Ca and Zn within an accuracy of 5%(Table 3). For the other 13 elements for which there were no certified or no reference values, the percent recoveries of 84-103% were obtained (Table 4).

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The determination of tin by inductively coupled plasma atomic emission spectrometry (ICP-AES) after solvent extraction with potassium xanthates (KRX) was investigated. Among KRX examined, potassium propylxanthate (KPrX) was the most suitable complexing reagent. The tin xanthate complex was quantitatively extracted into xylene from acidic solution. The optimum pH was between 0.2 and 1.5. KPrX concentration more than 0.06 mol⋅dm^-3 was required. The coexistence of 5 mg of Cu(II) and 2.5 mg of Ni(II)interfered positively on the determination of tin, but 100 mg of Al(III), 7 mg of Zn(II), 5 mg of Mg(II), 1 mg of Cu(II), Ni(II), Mn(II), Fe(III) and Si(IV), or O.5 mg of Cr(III), Ti(IV) and Zr(IV) had no significant interference on the determination of tin. The relative standard deviation for ten measurements in this method ran ged from 1.3 to 1.7% in the determination of 10.0, 30.0 and 50.0 μg of tin. This method was applied to the determination of tin in aluminium alloys and the analytical results agreed well with the certified values for the standard reference materials.

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The N1s XPS bands of picric acid are observed at 404.4 and 400.5 eV, whose intensity ratio is 2 : 1. This shows that three nitro groups of the acid are classified into two groups. The considerably large energy difference (3.9 eV) of the two bands indicates that two kinds of nitro groups are in significantly different chemical circumstances. The intense 404.4 eV band can be attributed to the p- and twisted ó-nitro groups, and the 400.5 eV one to the onitro group which is almost coplanar to the benzene plane. In the case of the picrate, the three N 1 s bnads are oberved at 404.3, 402.5, and 399.8 eV, their intensity ratio being 2: 1: 1. The intense 404.3 eV band is ascribed to the ionization from the nitrogen atoms of the p- and the twisted ó-nitro groups of the picrate, and the 399.8 eV band to the uninclined o-nitro group. The 402.5 eV band is assigned to the ionization from the N 1 s of the triethylammonium. It is found that the N 1 s ionization energy of triethylammonium cation is greatly influenced by the bulkiness of the counter anions, increasing with increase in the radii of the anions.

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In order to provide a HPLC standard sample ethylbenzene-3-sulfonic acid 8 was prepared from 3-aminoethylbenzene via sulfodiazotization and the subsequent oxidative chlorination, followed by hydrolysis of the sulfonyl chloride produced. Ethylbenzene was sulfonated with 98% sulfuric acid at temperatures of 20-120°C and the resulting sulfonic acid mixtures were analyzed by HPLC with aid of the standard samples. The HPLC analysis showed that 8 was formed in 0.3-3.8% yield along with the major products ethylbenzene-2- and 4-sulfonic acids.

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Changes of morphology and crystal structure of calcium oxalate in spinach by boiling in water were examined. Oxalic acid in spinach was extracted by 20 min' immersion in boiling water. Both of oxalic acid and calcium oxalate were extracted from spinach by one night's immersion in 0.1 M hydrochloric acid. The concentration of oxalic acid or that of the sum of oxalic acid and calcium oxalate in the extracts was determined by ion chromatography. From the difference between the above two concentrations, the quantity of calcium oxalate was obtained. Spinach (100 g) used in the present experiment contained 730 mg of oxalic acid and the sum of oxalic acid and calcium oxalate was 912 mg. Then calcium oxalate as dihydrate was calculated at 339 mg per 100 g of spinach. This sample was boiled for 8 hs and calcium oxalate remaining in spinach was obtained every one hour. The quantity of calcium oxalate decreased, which was more pronounced after 4 hs. After 8 h' boiling, about 26% calcium oxalate disappeared. After one hour's boiling, small holes and cracks began to appear on the surfaces of calcium oxalate crystals. After more than 8 h boiling, samall crystals of calcium oxalate monohydrate appeared on the surfaces of the initial crystals and X-ray diffraction showed that a half of calcium oxalate crystals in spinach changed into calcium oxalate monohydrate.

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Comb-shaped polystyrene was successively fractionated by using a preparative GPC and the samples with relatively narrow molecular weight distribution were obained. The weightaveraged molecular weights were determined by GPC-LALLS, and the intrinsic viscosity were measured for these comb-shaped polystyrenes in the THF solvent, and the relationship of log[η]log M_W, and the universal calibration curve in GPC were used in the characterization of comb-shaped polystyrene. Static branching pa rameter g, expressed by g=<S²_0b>/<S²₀>₁, where <S₀²>, and <S₀²>₁ are the square average gyration radius for branched and linear polystyrenes with same molecular weight, was calculated from the equation of Casassa-Berry. On the other hand, hydrodynamic branching parameter G, expressed by G=[η]_b/[η]₁, where [η]_b and [η]₁ are intrinsic viscosity for branched and linear polystyrenes with same molecular weight, was obtained. The exponent b in the relation of G=g^b was estimated and was 0.65.

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A poly(ammonium acrylate) was fractionated by gel filtration using TOYOPEARL gel and the direct characterization was carried out for the eluted solution. The carrier solvent used was O.2 M phosphoric acid buffer solution (pH = 6.9). Weight-average molecular weight M, and radius gyration R_G determined by light scattering and intrinsic viscosity [η] determined by viscosity measurement for each fraction decreased with the fraction number. Consequently, it was indicated that the fractionation was carried out according to molecular size. Using the relationship between the analytical GPC peak elution volume and Mw (GPC calibration) the ratio of M_W to number-average molecular weight M_n was obtained. It was found that the each of fraction obtained a fairly narrower (M_W/M_n) than the unfractionated sample and the ratio M_W/M_n is relatively smaller for those fractions at a lower elution volume range (M_W/M_n < 3). Fractionations by gel filtration and the analytical GPC measurements were repeated three times. The results of those fractionations gave good reproducibility.

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For the purpose of developing an adsorbent usable for extraction of boron from geothermal brines, the adsorption behavior of boron in agueous solution on hydrous cerium(IV) oxides was investigated by means of batch tests in the temperature range of 25-200°C. The hydrous cerium oxide with low crystallinity and large specific surface area had high adsorbability for boron. Amounts of adsorbed boron per unit surface area were approximated by a single Freundlich isotherm, irrespective of specimen used (Fig.3). As to the effect of adsorption temperature, it was fo und that the amount of adsorbed born increased with increasing temperature above 100°C (Fig.4). An infrared absorption peak (1470 cm^-1), which is attributable to the OH bending vibration of hydrous cerium oxide, decreased with increasing temperature above 100°C (Fig.8). Anion-exchange reaction between OH group and borate ion is promoted above 100°C due to the dissociation of OH groups under the hydrothermal conditions. The adsorbed boron could be eluted with dilute NaOH solution, therefore, hydrous cerium oxide can be used as an adsorbent suitable for extracting boron from hot water.

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Uranium (VI) adsorption and desorption properties of a chelating resin containing poly-aminesubstituted methylphosphonic acid moiety of 2.29 mmol/g-resin (APA) were examined. Uranium(VI) adsorption properties of several ion exchange resins and extractant age nts which were known as excellent adsorbents for uranium(VI), were examined together for a comparison with those of APA. Uranium(VI) adsorption capacity of APA at the concentration of 100 mg⋅dm^-3-urainum(VI) in 100 g⋅dm^-3-H₂SO₄ aq. soln., 190 gdm⋅^-3-H₃PO₄ aq. soln. and uranium enriched sea water, was O.2, 0.05 and 0.05 mmol⋅g^-1 respectively. The adsorption capacity of APA for uranium(VI) in these solutions was larger than that of another adsorbents, except the adsorption of uranium(VI) in enriched sea water on ion exchange, resin containing phosphoric acid moiety (adsorption capacity ; 0.2 mmol⋅g^-1). Uranium(VI) adsorption rate on APA was high and the relation between treatment time (t : min) and uranium(VI)concentration (y : mg⋅dm^-3) in 100 g⋅dm^-3 H₂SO₄ aq. soln. after treatment, was shown as following equation, y =20^0.048t+19.0 (0≤t≤30). The adsorbed uranium(VI) on APA was able to be eluted with a mixed aq. soln. of hydrogen peroxide and sodium hydroxide and also was able to be eluted with an aq. alkaline soln. dissolved reduction agents such as sodium sulfite and hydrazine. From these results, it was thought that uranium(VI) adsorbed on APA was eluted due to the reduction to uranium (IV) by these eluents.

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The dependency of the difference electronic spectrum of copper chlorophyllin (Cu-chin) on concentration was observed and it was found that a part of Cu-chin in aqueous solution dimerizes above 10^-3 mol⋅dm^-3. The center-center distance in this dimer is estmated to be 10.4 A and angle formed by Cu-chin planes to be 155°. The low temperature ESR spectrum of Cu-chin indicated that Cu-chin chagnes to polymer in aqueous solution but does not in 5% ethanol solution.

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It was found that Methylene Blue (MB) in dimethyl sulfoxide (DMS0) was reduced in dark even by cyclodextrin (CD), a-tocopherol and poly(vinyl alchol). The reduced product determined by means of the thin layer chromatography is a leuco Methylene Blue. The fading rate in dark depends on the degree of saponification of PVA, or on delocalization energy of tocopherols, and is retarded by addition of water, glycerol or urea in MB-DMSO-PVA system.

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