The main purpose of the present work is to concentrate traces of mercury from waste water or effluent. Mercury (1 to 3 ng per 100 ml) in aqueous solutions containing preserving reagents was collected with 100 mg of activated carbon (occasional stirring by hand for one hour). Mercury was then determined directly by combustion-gold trap-flameless atomic absorption spectrometry. Average recoveries of mercury(II) and methylmercury from 0.1 M nitric acid-10 ppm L-cysteine solution were 98% (n=9) and 97% (n=6), respectively, with relative standard deviations of 6.4% and 6.3%, respectively. Iodide interfered seriously with the collection-determination of mercury(II). Recoveries of mercury(II) from 0.8 M nitric acid-0.05% potassium dichromate solution and from 0.2 M sulfuric acid-0.05% potassium dichromate solution were low, but they were greatly improved by neutralizing the solutions with 5 M sodium hydroxide. Thus average recoveries and relative standard deviations were 100% (n=6) and 3.5%, respectively, for nitric acid-dichromate solution and 98% (n=6) and 1.9%, respectively, for sulfuric acid-dichromate solution. Recoveries of methylmercury after neutralizing these acid solutions were about 90%.

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It was found in this investigation that p-coumaric acid (4-hydroxycinnamic acid), which is known to be contained in rice plant and in natural water, is isomerized from trans-from to cis-form during analytical procedure by exposure to fluorescent light. A cis-form of p-coumaric acid was identified by NMR, GC and mass spectrometry. The degree of isomerization was dependent on the exposure time to fluorescent light and an alkalinity of the solution, and a maximum isomerization was observed in 30% NaOH (0.1 M) containing methanol solution. In this case, its value of ratio of cis-form to trans-form reached up to 3.0 during exposure for 24 h. The cis-isomerization did not take place when brown glass apparatuses were used throughout the course of this procedure, trimethylsilylated p-coumaric acid was kept at a low temperature (less than 10°C) and the measurements were finished within 8 h.

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The peak of copper by anodic stripping voltammetry with a hanging mercury drop electrode (HMDE) is enhanced markedly by the presence of an appropriate concentration of iodide ions in the solution in which the stripping is carried out. This effect provides a sensitive and selective method for the determination of copper. When copper was deposited on the HMDE for 5 min at -0.5 V vs. SCE and then stripped in 0.1 M acetate buffer solution (pH 4.5) containing iodide ions of 2.0×10^-4M by the linear potential scan at the rate of 10 mV/s, the stripping peak became to be very sharp and shifted to positive potential and the peak current increased about 7 times as large as that in the solution without iodide ions. This peak current was proportional to the concentration of copper over the range of 1×10^-7M1×10^-6 M and also to the deposition time between 1 min and 10 min. The relative standard deviation for five runs at 1×10^-6 M Cu(II) was ca.3%. The half-peak width of this stripping peak was 6 mV and so sharp that the resolution from bismuth peak came to be excellent. The effects of co-existing ions on the determination of copper in the presence of iodide ions were also studied and the co-existence of chloride and bromide ions was permitted up to 1×10^-2 M, and 5^×10-3 M, respectively.

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The spectrophotometric determination of lead(II) with 5-nitro-2-[3-(4-p-sulfophenylazophenyl)-1-triazene]-benzenearsonic acid (Sulfoarsazene), especially how to mask the interference of other elements was described. The interference of Cu(II), Cd(II), Ni(II), Co(II), Hg(II), Zn(II), V(V) and Cr(III) was masked with the addition of proper amounts of potassium cyanide or hydrogen peroxide. As Fe(III) was not masked with any kind of reagent, it was separated by means of the solvent extraction using isopentyl acetate and hydrochloric acid. The following procedure to determine lead(II) in ambient particulates was established. A given amount of sample containing less than 50μg of lead was gently heated in concentrated hydrochloric acid together with a small amount of hydrogen peroxide on a hot plate. After filtering the insoluble residue off, the filtrate was evaporated to nearly dryness. The residue was dissolved in 20 ml of concentrated hydrochloric acid, and Fe(III) was removed by the solvent extraction using 20 ml of isopentyl acetate. After excess of hydrochloric acid in the water phase was removed by evaporating, lead(II) was extracted into 20 ml of benzene with sodium diethyldithiocarbamate. The benzene phase was transferred in a beaker and it was evaporated to remove benzene. Then, 10 ml of 6 mol/1 nitric acid and 2 ml of 30% hydrogen peroxide was added into it, and the solution was evaporated to dryness. The residue was dissolved in 5 ml of 0.05 mo1/1 nitric acid, and 2 ml of 0.2mol/1 sodium borate solution, 1.4 ml of 0.05% sulfoarsazene solution and 1.6 ml of water was added. The an alytical values obtained by the proposed method was in agreement with those obtained by atomic absorption spectroscopy within ±10% of error.

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An amperometric titration measuring the reduction current of potassium iodate for the determination of hydroxylamine salts has been studied with a rotating platinum electrode (2000 rpm) at the potential of +0.6 V vs. SCE. It was found that hydroxylamine salts could be titrated at (4550)°C by adding 0.025 ml or 0.05 ml portions of potassium iodate standard solution at intervals of 20 s in the presence of hydrochloric acid, potassium bromide and sodium chloride. Hydroxylamine hydrochloride was determined with the relative error(r.e.) and the coefficient of variation (c.v.) of about 0.2% at its concentration from 4×10^-4 M to 10^-2 M. Hydroxylamine sulfate was determined with the r.e. and the c.v. of about 0.2% at its concentration from 2×10^-4 M to 4×10^-3 M. The presence of ammonium and nitrate ions did not interfere with the titration. The recommended procedure is as follows. Weigh accurately about (230)mg of hydroxylamine salts in the titration cell. Dissolve it by adding 7 ml of 6 M hydrochloric acid, 4 ml of 4 M potassium bromide, 16 g of sodium chloride, and dilute with water to 50 ml. Titrate the resultant solution with (0.010.1)M potassium iodate solution amperometrically. The whole procedure requires less than 20 min.

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It has been found that the complexation of α, β, γ, δ-tetrakis (1-methy1-3-pyridyl) porphine [T (3-MPy)P] or α, β, γ, δ-tetrakis (1-methyl-4-pyridyl) porphine [T(4-MPy)P] with copper(II) is accelerated remarkably by adding a small amount of a reducing agent such as hydroxylamine, ascorbic acid or sulfite, and is completed almost instantaneously even at room temperature. On the basis of this finding, two highly selective spectrophotometric methods have been developed and proposed for the determination of copper at ppb level. In the method using T(3-MPy)P, the calibration curve obeyed Beer's law up to at least 140 ppb of copper and the sensitivity for 0.001 absorbance was 0.17₉ng Cu/cm². In the method using T(4-MPy)P, the calibration curve was linear up to 190 ppb and the sensitivity was 0.25₈ ng Cu/cm². The procedure of the T(3-MPy)-P method is as follows; To a 25-ml volumetric flask, a sample solution containing less than 3.5μg of copper, 1 ml of 0.5% hydroxylamine hydrochloride solution, 1 ml of 1 M acetate buffer solution(pH 5) and 1 ml of 6×10^-5 M T(3-MPy)P solution are added. After standing for about 2 min, 4 ml of sulfuric acid(1+1) is added and then the solution is diluted to the mark with water. The absorbance of the solution is measured at 434 nm against water. The method was applied to the determination of copper in analytical reagents, cement and steel with good accuracy and reproducibility.

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The synergistic effect of a pyridine base on the extraction of iron(II) with dibenzoylmethane(DBM) was studied and the synergistic adducts examined were classified into two groups through absorption spectral measurements. By employing the orange colored trioctylphosphine oxide (TOPO) adduct, a highly sensitive and selective spectrophotometric method for the determination of iron(II) was established: Take a sample solution containing less than 40μg of iron(II) in a separatory funnel, add 1.0 cm³ of 10% hydroxylamine hydrochloride, and adjust pH to 6.6 by adding sodium tetraborate buffer solution. Add 10 cm³ of benzene solution of DBM (1.0×10^-2 mol dm^-3) and TOPO (3.0×10^-2 mol dm^-3). Shake the mixture for 10 min, and measure the absorbance of the organic phase at 408 nm. The molar absorptivity and the Sandell sensitivity were 1.2×10⁴ dm³ mol^-1 cm^-1 and 0.0047μg cm^-2, respectively. Analytical reaction in the above procedure could be explained by the formation of an adduct Fe(DBM)₂(TOPO)₂, and the present method was successfully applied to water analysis.

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The gas chromatographic separation of the enantiomers of various arylalkylamines {α-phenylethylamine (I), α-phenylpropylamine (II), α-(2, 5-xylyl) ethylamine (III), α-(1-naphthyl)ethylamine(IV), α-(2-naphthyl)ethylamine(V), α, β-diphenylethylamine(VI) and α-phenyl-β-(4-tolyl)ethylamine(VII)} in the form of N-trifluoroacetyl or N-pentafluoropropionyl derivatives with a chiral stationary phase has been studied. These arylalkylamines were resolved with separation factors ranging from 1.023 to 1.063 on a 40 m glass capillary column coated with N, N'-[2, 4-(6-ethoxy-1, 3, 5-triazine)diyl]-bis- (L-valyl-L-valyl-L-valine isopropyl ester). Rather high column temperature serves for the rapid elution, for example, α-phenylethylamine enantiomers have been separated within 10 min at 150 °C. The highest separation factor is obtained for (III) and (IV). The separation factors of (VI) and (VII) are not so large (1.023 and 1.025 at 180°C), but are sufficient for determination of their optical purity, because the resolution values are 1.34 and 1.28, respectively. It is noticed that the order of emergence observed on this phase is (+)-isomer before (-)-isomer in α-arylalkylamines {(I) to (V)} and vice versa in α, β-diarylalkylamines {(VI) and (VII)}. From the point of view of the absolute configuration, it is concluded that the R-isomer emerges earlier than the S-isomer in every arylalkylamine, because it is known that (+)-isomers of (I) to (V) and (-)-isomers of (VI) and (VII) have R-configuration. We consider that this fact gives the interesting information on the diastereomeric intermolecular interactions of arylalkylamine enantiomers.

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For the concentration of trace heavy metal ions, 5-sulfo-8-quinolinol (QSA) was used as a chelating agent for heavy metals to form soluble chelates and adsorption behavior of these metal-QSA chelates onto an anion exchange resin was studied, and the atomic absorption spectrophotometric method for the determination of several heavy metals was established. The recommended analytical procedure is as follows; to 3 l of river water, which was filtered through a membrane filter (MFHA), was added (15) ml of 2% QSA solution and pH of the solution was adjusted to 88.5, then the solution was introduced onto an anion exchange column {Dowex 1-X 8, (100200) mesh, Cl form, i.d. 10 mm, height 50 mm} at a flow rate of (56) ml/min and adsorbed heavy metals were eluted with 25 ml of 2M HNO₃. Then, the quantities of Cu(II), Zn(II), Mn(II), and Pb(II) in the effluent were determined by atomic absorption spectrophotometry. The relative standard deviations for Cu(II), Zn(II), and Mn(II) in river water were estimated to be less than 5.4%, 6.9%, and 3.1%, respectively. The recommended procedure is useful to minimize the storage problem caused by the hydrolysis and the adsorption loss of minor elements in sample water.

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Two couples of biological guaiacol estrogen isomers and a couple of synthetic ones were separated satisfactory by thin-layer chromatography by using continuous developing technique. The chromatographic plates were Merck silica gel 60 F₂₅₄ (No. 5715) and spotted plates were developed continuously. Following solvents were used: benzene for the separation of 2-methoxy-estrone (II) and 2-hydroxyestrone-3-methyl ether (III), 2% acetone in benzene for the mixture of 2-methoxyestradiol(V) and 2-hydroxyestradiol-3-methyl ether (VI), and 5% acetone in benzene for 2-methoxy-3, 17 β-dihydroxyestra-1, 3, 5(10)-trien-6-one (VIII) and 3-methoxy-2, 17β-dihydroxyestra-1, 3, 5 (10)-trien-6-one (IX). Combination of the present separation technique with thin-layer chromato-scanner made possible for the estimation of guaiacol estrogens. Calibration curves between the spotted steroid amounts and peak area on chromatograms were shown to be linear in the range of (0.510.0) μg for II, III, V, and VI, and (0.210) μg for VIII and IX. Estimation of radioactive guaiacols obtained by the incubation of catechol estrogens with rat liver catechol O-methyl transferase in the presence of S-adenosyl-L-methionine (³H₃C) was also possible by using radio thin-layer chromato-scanner.

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The combined use of organic solvent extraction and graphite furnace atomic absorption spectrometry is useful for removal of matrix interferences. But the precision tends to lower because of vaporization of organic solvent. In the use of an autosampler, vaporization of organic solvent causes error owing to long standing time before measurement in treating many samples. Copper-, lead-, and cadmium-diethyldithiocarbamates were investigated in various organic solvents. Absorbance of copper in methyl isobutyl ketone and chloroform increased with the standing time more than 30 min. To prevent the vaporization of organic solvent, the equilibrated aqueous solution or water was placed on the top of the organic solvent such as chloroform or carbon tetrachloride. By this method, the absorbance of metal in organic solvent, chloroform or carbon tetrachloride, did not increase for period up to 4 h. The use of an autosampler improved the precision, especially in the case of chloroform and carbon tetrachloride. The precision in organic solvent was comparable with that in aqueous standard solution.

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A highly sensitive method for the determination of trace amounts of manganese(II) with dithizone (H₂Dz) was established. This method is based on the complex formation of an adduct, Mn(HDz)₂(phen). The extracted complex has an absorption maximum at 507 nm and the absorbance is stable at least for 1 h. The analytical procedure is as follows: Take a sample solution containing less than 5 μg of manganese(II) in a separatory funnel, then add each 2.0 ml of 10% tartrate solution and hydroxylamine hydrochloride solution. Adjust the pH of the solution to about 6.0 by adding hydrochloric acid or ammonia. Extract the coexisting ions preliminarily using 5 ml of 0.02% dithizone solution in chloroform for 30 min. After washing the aqueous phase with a few milliliters of chloroform, extract manganese (II) with 10 ml of 0.001% dithizone and 0.01 M ο-phenanthroline in chloroform by shaking for 1 min. Allow the phases to separate, measure the absorbance of the organic phase at 507 nm against thereagent blank. Under the optimum conditions, a proportionality between the absorbance and manganese (II) concentration was obtained below 5.0μg of manganese(II). The molar absorptivity was obtained to be 4.6×10⁴ dm³ mol^-1 cm^-1, the sensitivity being 0.0011 μg Mn/cm². The coefficient of variation of the absorbance measurments for 3.0 μg of manganese(II) was 1.3%. No interference with the determination of 3.0 μg of manganese (II) was found for each 100 μg of copper (II), iron(II), zinc(II), and cadmium(II), and for each 40 μg of cobalt(II), nickel(II), zinc(II), mercury (II) and 10μg of chromium(III). The method was applied to the determination of manganese(II) in carbonate rocks and hot spring waters.

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A new gas chromatographic method for aldehydes analysis with their imidazolidine derivatives was developed. N, N'-diphenylethylenediamine easily reacts with aldehydes to form the imidazolidine derivative in the presence of acid catalyst. Differing from the peak of 2, 4-dinitrophenylhydrazone on a gas chromatogram, the peak corresponding to the imidazolidine derivative is single because of the absence of geometrical isomers. The gas chromatographic conditions were as follows : column packing, 1% PEG-HT on Chromosorb WAW DMCS; column size, 2 mm i.d. ×2.25 m or 3 m; detector, FID; column temp., (235265)°C (1°C/min); inj. port, 265°C; detector temp., 265°C. The imidazolidine derivatives of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, iso-butyraldehyde, furfural, benzaldehyde and ο-tolualdehyde were clearly separated by the gas chromatographic conditions presented above. But, when acetaldehyde and butyraldehyde are mixed together, each aldehyde can't be identified because the retention time of both imidazolidine derivatives overlaps each other. In such a case, each aldehyde should be identified by using column packing of both 2% OV-17 and 1% PEG-HT. The relative mole response to anthracene as internal standard substance are as follows: the formaldehyde derivative, 0.85; the acetaldehyde derivative, 0.92; the propionaldehyde derivative, 1.18. The presented method was applied to analyse aldehydes in the cigarette smoke and the exhaust gas of automobiles, and several aldehydes were identified in both cases. The gas chromatographic method presented above can be used for analysis of aldehydes as their imidazolidine derivatives.

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Lead in bay sediment was separated to two fractions. One fraction was obtained by leaching dried sample (1 g) with a mixture of 1 M hydroxylamine hydrochloride and 25% (v/v) acetic acid, and the other obtained by dissolving the residue in nitric acid. Two sample solutions were finally dissolved in 0.01 M hydrochloric acid (100 ml). Various elements coexisting in these solutions interfered with measurement of lead by atomic absorption spectrometry with graphite furnace. The interference on determination of lead with direct and DDTC-MIBK extraction methods from 10 foreign elements, i.e., Na, K, Mg, Ca, Fe, Mn, Si, Al, Cu and Zn was investigated individually. Further, the direct, standard addition and extraction methods were compared each other by using sample solutions containing 100 ppb of lead and 10 foreign elements which was treated in the same way that of sample solution of bay sediments. To minimize the interference, the extraction method after diluting the sample solution to one-tenth was preferred. Present method was applied to the analysis of sediments of Hiro Bay in Hiroshima Prefecture.

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The reliability for determination of cobalt in biological samples was studied by using various analytical methods such as atomic absorption spectrometry (AAS), absorption photometry(AP), and instrumental neutron activation analysis (INAA). The marine samples used were various kinds of shellfish which were dried at 105°C and then ashed at 500°C in an electric furnace. After the ashes were decomposed with HF, HNO₃ and fuming HNO₃, followed by evaporation to dryness, the residues were dissolved in dilute HCl and were analysed by AAS and AP. In the AAS method the absorbance was directly measured at 240.7 nm using air-C₂H₂ flame. In the AP method cobalt was first extracted into xylene with 1-nitroso-2-naphtol reagent, and then the absorbance was measured at 410 nm. In the INAA method, the ash sample and the reference standard were irradiated for 24 h at a thermal neutron flux of 5×10¹¹ n cm^-2 s^-1 in the TRIGA II reactor at Rikkyo University, and after cooling for 15 days the 1332 keV gamma ray was measured by a Ge(Li) detector coupled with a multichannel pulse height analyser. The analytical results were (in μg Co/g wet tissue) : 0.49 (AAS). 0.22 (AP) and 0.21 (INAA) in Tapes philippinarum; 0.28 (AAS), 0.081 (AP) and 0.077 (INAA) in Mytilus edulis; 1.2 (AAS), 1.1 (AP), and 0.95 (INAA) in Tridacna squamosa, respectively. Values obtained by AP and INAA agreed well each other, whereas those obtained by AAS were higher than the corresponding values obtained by the former two methods. The origine of the higher values was found to be the interference by iron and calcium in the samples. The reliability of AP and INAA were confirmed by the analysis of Bovine Liver (NBS standard reference material) and standard rock samples AGV-1 and JG-1.

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Gas chromatographic determination of residual acetaldehyde in PET bottles was developed. The presence of residual acetaldehyde in PET bottles may forbid these bottles to be used for food packing materials since relatively low amounts may influence the smell and the taste. A known amount of polymer sample was heated at 150°C under nitrogen atmosphere during 10 min in a glass tube fixed in the pyrolyzer. The free acetaldehyde was directly carried to a gas chromatograph connected with the pyrolyzer and was analyzed quantitatively with calibration standard of acetaldehyde. Thus quantitative analysis of acetaldehyde in PET can be done conveniently by this method with a small quantity of sample and will be useful for food chemistry and food sanitation chemistry.

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