A thermometric titration method is described for the determination of dodecyl sulfate (DS) and dodecylbenzene sulfonate (DBS) with tetradecyldimethylbenzyl ammonium (Zephiramine). Heats of the reactions of DS and DBS with Zephiramine are determined to be -84.4 and -19.8 kJ mol^-1, respectively. Addition of polyvinylalcohol (PVA) is found to inhibit the undesired coagulation of the DS- and DBS-Zephiramine precipitates, giving a sharp end point by improving the shape of the titration curves. A few mM solution of DS and DBS can be easily determined within 1 per cent.

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Colorimetric determination of fluoride ion in drinking water was done with a long capillary cell (LCC) (length:0.7-4m). When a solution whose refractive index exceeds that of the cell material (Pyrex=1.474) is put into the capillary, a wave-guide(total reflection) cell is obtained, its transmissibility to source light is independent of cell shape. Color development was based on the la-ALC method: lanthanum-alizarin complexone was added to the sample. The fluoro-lanthanum-alizarin complexone which formed was combined with N, N-diethylaniline and extracted into isoamyl alcohol. Fluoride complex extracted to isoamyl alcohol was mixed with a mixture of carbon disulfide and acetone (the final refractive index of analyte solution=1.57). Extension of cell length longer than 1m provided highly sensitive colorimetry.Enhancement of absorption was O.5-2.5×10³times in magnitude by using 4m LCC. Detection limit and recovery of this method were 10ng/l and 93-104% (for 50μg/l), respectively. The present method was applied to the determination of fluoride in drinking water collected around Tokyo.

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A new analytical procedure for strontium in seawater was developed: a capillary-type isotachophoresis which applies the ion exchange method is used. Large amounts of coexisting sodium, magnesium, calcium and potassium interfered with the isotachophoretic measurement of strontium. Therefore, after the seawater sample was passed through the column packed with a sodium cation-exchange resin, calcium was removed with 5.0×10^-3M EDTA solution adjusted to pH 6.6 and then strontium was eluted with 5.0×10^-3M GEDTA solution adjusted to pH 10.0. Magnesium was eluted little by little with EDTA solution but was not with GEDTA solution. The isotachophoretic determination was performed with an analyzer equipped with a potential gradient detector and a 40-cm- long main column connected to a 10-cm-long precolumn. The leading electrolyte was a mixed solution of 0.01M hydrochloric acid and 0.1% hydroxypropyl methylcellulose, of which the pH was adjusted to 9.0 with tris- (hydroxymethyl)aminomethane. A terminating electrolyte was 0.01M sodium hexanoate. A linear working curve was obtained for artificial seawater samples containing up to 16mg/l of strontium. The proposed method was applied to the determination of strontium in surface seawater samples collected around the coastal area of Osaka Bay in September, 1985. Reproducible values were obtained by the standard addition method.

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By the combined use of the decomposition of different sample sizes (1-300mg) in a sealed PTFE vessel and the atomic spectrometric measurement of elements with discrete nebulization technique, the homogeneity of NBS-SRM 1566 Oyster Tissue and 1577 Bovine Liver and NIES-CRM No. 1 Pepperbush, No. 5 Hair, No. 6 Mussel, and No. 7 Tea leaves was assessed from the relative standard deviations of the analytical results for elements. Irrespective of the sample sizes used, the small relative standard deviations of the analytical results could show the good homogeneity of the elements in the samples. But calcium in Oyster Tissue was undoubtedly inhomogeneous and iron in Oyster Tissue, Mussel, and Tea leaves showed somewhat poor homogeneity, i.e., the comparatively large relative standard deviation.

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A novel chemical modification employing TCNQ is proposed as a preparation technique of ion sensing membrane. The silver ion sensor which links coated wire electrode to the gate lead-wire of a conventional FET showed linear response to silver ion activity in the range from 10^-5mol dm^-3 to 10^-mol dm^-3 with an almost Nernstian slope. Hg²⁺ interfered strongly with Ag(TCNQ^_??_) thin film, however, the selectivity coefficients for other ions were below 10^-4. The silver ion sensor gave stable potential after a slight drift during 2.5h. The response time of the proposed sensor was less than 10s from low to high concentration and in the reverse case the response time became less than 30s.

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An automated method based on on-line sample enrichment by precolumn switching has been developed for the determination of hop bittering components in beer and wort. A combination of two columns was used: a tetramethylolmethanetriacrylate type for trapping and an ODS silica type for final separation. Iso-α-acids and α- acids were determined with similar results by the conventional method, based on off-line sample enrichment (liquid- liquid extraction and concentration). The analysis was carried out with good reproducibilities (rsd less than 3%). Precolumn switching is distinguished by injection of beer and wort samples without preteatment, and is eminently suited for automated routine analysis in breweries.

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The Na, K, Ca, Mg, Fe, Cu, Mn and Zn contents of hashish batches in judicial seizing were determined in order to confirm, once again, the reliability (expressed by precision and accuracy) of the "Carbonaceous Slurry" as pretreatment of complex organic matrices prior to analysis. The analysis of pressed cakes of five different batches also served to prove the homogeneity of the analytical data in a statistical sense both related to one cake (relative standard deviation) and to different cakes of one batch (t-test) as well as to determine the equality or the non- equality of the batches on the basis of the analytical data (variance analysis, Duncan-test).

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Using flame atomic absorption spectrometry with discrete nebulization, zinc, copper, iron and magnesium were measured in a total of 100μl of serum after the four-fold dilution with Triton X-100 without removal of proteins. The final concentration of the detergent was 0.02%. For magnesium measurement, the sample solution was further diluted five times with blank solution. Every measurement was carried out with duplicate injections of 50μl of the sample solution. Standards for calibration were similarly prepared from Auto Cal 1 for matrix matching. Present method enabled the analysis of 90 samples/h without any loss in accuracy or reproducibility.

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The proposed determination of gold(III) is based on the formation of dicyanoaurate(I) and its extraction into 1, 2-dichloroethane as an ion-pair with Methylene Blue. The optimum pH range for the formation of dicyanoaurate(I) is 2.2-7.2 under the conditions described. The absorbance of the extract is stable for at least 4 days in a glass-stoppered tube. The apparent molar absorptivity for gold is 1.08×10⁵l mol^-1 cm^-1 and the Sandell sensitivity for 0.001 absorbance is 1.8×10^-3μgAu cm^-2 at 657nm. Linear calibration graphs are obtained over the range 2×10^-7-8×10^-6M gold(III) (0.4-15.8μgAu in 10ml); at the 6×10^-6M gold(III) level, the relative standard deviation is 0.2%.

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Adsorption behavior was investigated for five metals that form chloro-complexes on Amberlite XAD-4, XAD-7, XAD-8 and chelating resin Chelex 100 from hydrochloric acid solution. XAAD-7, XAD-8 and Chelex 100 adsorbed efficiently the metals; suitable hydrochloric acid concentrations were _??_6M for iron(III), _??_0.1M for gold(III), _??_5M for gallium(III), 0.1-8M for thallium(III) and 6-11M for antimony(V) (M=mol l^-1). The metals were also adsorbed considerably on XAD-4 and Unicellex A {only iron(III) and antimony(V) were examined}. The extent of adsorption decreased with an increase in the concentration of the metals and the adsorption isotherms were found to be langmuir type. The capacities of XAD-7, XAD-8 and Chelex 100 for the metals were in the range 0.4-0.9mmol g^-1 (weight after drying at 60°C). When hydrochloric acid is used to elute iron from Chelex 100, 1M hydrochloric acid is suitable but 10M is not. Possible adsorption mechanisms were discussed briefly.

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Major and minor constituents, Sm, Ce, Y, Co, Fe, Mn, Cu, Zr and Hf, in typical rare earth-cobalt magnets were determined sequentially by inductively coupled plasma atomic emission spectrometry. Sample solutions were prepared by dissolving the magnets with aqua regia followed by dilution with 1.2M HCl to suitable concentration. Beryllium was added as an internal standard in order to improved experimental accuracy and precision, and the emission intensity of Be was measured by using an additional small monochromator attached to the original instrument system. Cobalt, Fe, Cu and Zr in the magnets were also determined by conventional spectrophotometry. The results obtained by both methods were in good agreement with each other.

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Liquid-liquid extraction of Ni(II) ion by Kelex 100 and 8-sulfonamidoquinolines in chlorobenzene was studied at 25°C. The extraction equilibrium was established only slowly, requiring generally 24h mechanical shaking. The extractants (HL) behaved as bidentate monoanionic chelating ligands, forming 1:2 (Ni²⁺:L^-) complexes on metal extraction. The overall extraction constants (log K_ex; K_ex=[NiL₂]_org[H⁺]²_aq/[Ni²⁺]_aq[HL]²_org were in the order of -6 for Kelex 100 and in the range of -8--10 for 8-sulfonamidoquinolines depending on the nature of organic sulfonyl groups. A small synergistic effect by trioctylphosphine oxide, 4-benzylpyridine and 6-nitroquinoline as well as by Kelex 100 itself was observed in the extraction by Kelex 100.

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The waste water sample is pumped at the flow rate of 4cm³ min^-1 to the mixing joint, where a reaction solution (5×10^-3M bismuth nitrate-containing sodium acetate buffer at pH 5.0) is mixed at the rate of 1cm³ min^-1. Then the mixture containing hydrogen cyanide is fed into a gas-liquid separator. The hydrogen cyanide permeates through a Teflon membrane (0.80μm pore size, 0.08mm thick) into an absorption solution (0.02% sodium hydroxide) flowing at 24cm^-3 h^-1. The cyanide ion produced is measured with the cyanide selective electrode. The response time is about 1.3min at a concentration of 1×10^-4M cyanide. The Nernst equation is valid with a relative standard deviation of less than 2.8% in the range between 1×10^-3 and 1×10^-6M. The lower detection limit is 1×10^-7M (2.6 CN^- ppb). This method can detect free cyanide ion and indirectly metal cyano complexes whose stability constants are below 10¹⁷.

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A new procedure for sensitive and selective determination of stimulant drugs in urine is described. The method consists of extracting the organic base in alkaline media and performing the color reaction with tetrabromophenolphthalein ethyl ester molecule. Colored products have maximum absorption at 570nm for methamphetamine, 555nm for ephedrine and 550nm for methylephedrine, respectively. The optimal conditions - pH on extraction of organic bases, shaking time, concentration of dye, percentage extraction of the bases and the linear ranges of calibration curves are investigated for the determinations of methamphetamine, ephedrine and methylephedrine. The extracting solvent used is 1, 2-dichloroethane. This new method allows the sensitive and selective determination of methamphetamine, ephedrine and/or methylephedrine in urine.

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Quinoxaline derivatives formed from malto-oligosaccharides (maltose, maltotriose, maltotetraose, maltopentaose, and maltohexaose) and o-phenylenediamine (OPD) under alkaline and heated conditions were studied for the measurement of the degree of polymerization by HPLC analysis. 2′S)-2-(2′, 3′-Dihydroxypropyl)-3-hydroxymethyl- quinoxaline (M-1) from reducing end residue and six quinoxalines from non-reducing end residue were obtained by the alkaline OPD method. The ratio of the peak area for M-1 to 2-methylquinoxaline (G-VI) was proportional to the degree of polymerization of the malto-oligosaccharides tested. From 6²-O-α-maltosyl maltotriose, which has both 1, 4- and 1, 6-linkages, a quinoxaline having a sugar moiety in its branch was separated with other smaller quinoxalines. From this chromatogram, some proportional relationships between the ratio of this quinoxaline to G-VI and the average number of branched chain were estimated.

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The degradation process of calmodulin with trypsin in the presence or absence of calcium ions was reinvestigated by the analysis on HPLC. All tryptic peptides and intermediate peptides were mapped on this system. On the basis of these results, the strategy of the preparation of various calmodulin fragments was devised. Twelve peptides which contain calcium binding sites were obtained.

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The effect of organic solvents or additives was studied for the anion-exchange extraction reaction, (Q•Br)_o+(X^-)_w_??_(Q•X)_o+(Br^-)_w (Q⁺: liquid anion-exchanger; X: Cl^-, I^-, ClO₄^-; subscripts o and w denote organic and aqueous phases, respectively), with a special interest in the solvation of extracted anionic species by protic solvents or additives. The preference of extraction generally followed the order ClO₄^->I^->Br^->Cl^-, whether the solvent is protic or aprotic. However, protic compounds such as phenols, alcohols, sulfonamides, carboxamides, and chloroform when used as solvent or additive showed a mitigating effect on such extraction preference. lipophilic phenols such as p-t-octylphenol (p-(1, 1, 3, 3-tetramethylbutyl)phenol) and p-nonylphenol were especially efficient in enhancing the extractability of small (and thus hydrophilic) anions. The effect of substituents on the phenol was investigated. o-Chlorination or o-bromination of p-t-octyl phenol lead to the increase of small-anion extractability. On the contrary, the o-nitration considerably lowered the ability of phenolic compound in assisting the extraction of small anions. o, o′-Dibromination and o, o′-dimethylation lead to further lowering of such ability. The mechanism of protic solvation and its importance in determining the extraction selectivity among Cl^-, Br^-, I^-, and ClO₄^- were discussed.

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The light scanning photoacoustic densitometry was applied to sodium dodecylsulfate polyacrylamide gel electrophoresis. A near-infrared laser diode and a light emitting diode were used as light sources. Electrophoresed protein was silver stained, followed by vacuum drying. The photoacoustic signal amplitude from 0.10μg ovalbumin depended on the chopping frequency, f, as a function of f^-3/2 over 60Hz, and as f^-1 below 60Hz. The background signal was reduced by increasing the chopping frequency. The detection limits of bovine serum albumin, ovalbumin, tripsiongen, and hemoglobin were about 0.6, 0.5, 0.8 and 0.3ng respectively, using a laser diode.

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A simple and highly sensitive method for the determination of free and total (free+conjugated) catecholamines (norepinephrine, epinephrine and dopamine) in human erythrocytes, platelets and plasma is described which employs high performance liquid chromatography with fluorescence detection. Conjugated atecholamines are hydrolyzed by sulfatase-mediated reaction to the corresponding free amines. After cation exchange chromatography on a cartridge of a cation exchanger, Toyopak SP, catecholamines and isoproterenol (internal standard) in a sample are converted into the corresponding fluorescent compounds by reaction with 1, 2-diphenylethylenediamine. These compounds are separated on a reversed-phase column, TSK-gel ODS-120T, with isocratic elution using a mixture of water, methanol and acetonitrile containing a Tris•hydrochloric acid buffer (pH 7.0). The detection limit for each catecholamine is a. fmol/100-μl injection volume.

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