A correlation coefficient method is applied to the computer retrieval of infrared spectra by using 455 digitized spectra of solid and liquid samples. The effect of the sampling technique for solid samples are studied for determing the tolerance of the correlation coefficient, R, and it is concluded that the correct spectrum may give the value of R greater than 0.95. The frequency range adequate for the method is also discussed. The frequency of the strongest absorption band and the 1st4th moments of spectra are used in order to save the computation time before calculating R. It is suggested that the correlation co efficient method can identify all compounds except for the compounds which are not distinguishable essentially by only infrared spectrum.

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A simple and rapid semiquantitative procedure has been developed for the determination of sub-ppm level of cadmium in environmental aquatic samples by using an analytical micro-column packed with reagent gel beads. Reagent gel beads were prepared by treating the cross-linked polystyrene beads {2 % divinylbenzene, (70100)mesh in dry condition} with 0.02 % chlorobenzene solution of 6-brormo-2-benzothiazolylazo-2-naphthol (BTAN) for 24 h at room temperature. The gel beads were packed into a glass column (2.5 mm bore, 120 mm length). When a sample solution containing cadmium, buffered to pH 10 with Clark-Lubs buffer, was passed through the BTAN gel column at a flow rate of 0.2 ml/min, the original pink color of the reagent gel turned to redviolet from the up-stream of the column. As the length of colored band was proportional to the total amount of cadmium in the sample solution passed through the column, the concentration of cadmium can be determined from the calibration line which had been prepared by using the standard solution. Cadmium ion at (0.050.1) ppm and (0.20.5) ppm levels could be determined with ± 10 % and ±5 % relative errors, respectively. Of the foreign metals, 40-fold excess of Cr (VI), 20-fold excess of Al and Ni, 10-fold excess of Co (II), Hg(II), Fe (III) and Ag, and 5-fold excess of Cu (II) could be masked with Zincon, Tiron, thiourea and sodium fluoride. As for Zn (II), interferences could be masked up to identical amount with Cd with Zincon. This method was successfully applied to the analysis of cadmium in environmental aquatic samples.

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The relations between the concentration of trace water in anhydrous hydrofluoric acid (AHF) and its conductivity were investigated by the additional method in closed system. The conductivity was measured by the conductivity cells with the smooth platinum electrodes (cell constants from 0.3 to 3 cm^-1)at fixed frequency from 1000 to 3000 Hz. The correction for polarization error at frequency over 1000 Hz was negligible small. The effect of temperature on conductivity was : k=k_t(1 +0.0098t) where k : conductivity at 0°C, k_t : conductivity at ±t°C. The variation of conductivity was examined when the known amount of water or other impurities were added to high purity AHF. The relations between the conductivity (k, Ω ^-1 cm ^-1) and the concentration of water (C, ppm) less than 100 ppm, at which concentration Karl Fischer method was inapplicable, were
C, (110) ppm : log C=1.00 log k + 4.62
C, (10100) ppm : log C= 1.06 log k + 4.84
The conductivity was not affected by the presence of HSO₃F, H₂SiF₆ and SO₂ at the concentration of each several hundred ppm. The flow cells of by-pass type and on-stream type were developed by directly connecting with storage tank and pipe line. The use of the smooth platinum electrodes was necessary for stability and life of those cells. By using this new technique, the continuous measurements of the trace water at ppm level in AHF which has low conductivity at 10 ^-5 Ω ^-1cm ^-1level have been made possible.

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A new method for the determination of trimethylamine in air was studied and the following procedure was established. Trimethylamine in air was sampled at a flow rate of 2 1/min with a sampling tube, which was a 5 mm i. d. × 20 cm glass tube packed with 4 g of (1630) mesh glass beads coated with 0.2 % tartaric acid. Air in the sampling tube was exchanged for nitrogen gas. The sampling tube was installed in a gas chromatograph (FID). The temperature of the sampling tube was elevated from room temperature to 120°C in 25 s, and immediately 25 μl of 15 % ammonia water was injected into the sampling tube. Trimethylamine desorbed was transferred to a gas chromatograph and determined. In this method, the average recovery of trimethylamine was 99.7% and 3.5 % in the coefficient of variation. Trimethylamine was stable in the sampling tube for 96 h after sampling. This method was applied to the determination of trimethylamine in air of a mouse-breeding room and (9.610.0) ppb of trimethylamine was detected. The lower limit of quantitative determination was 0.2 ppb when 20 1 air was flowed. By this method trimethylamine in air is determined simply, rapidly, and precisely.

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The high energy pre-spark discharge was applied to the emission spectrochemical analysis of sulfur in sulfur free cutting steel and other steels in order to improve the precision. The results are as follows. (1) By applying the high energy pre-spark discharge technique, the accuracy (σ_d) was improved from 0.0096 % to 0.0014 % for sulfur { (0.0110.027) %; mean 0.020 %} in 23 kinds of steel samples. (2) Sulfur free cutting steel can be practically analyzed by this method with the accuracy (σ_d) of 0.0048 % for sulfur {(0.0350.32)%} in 45 kinds of samples. (3) It was confirmed by electron probe X-ray microanalyzer that the distribution of manganese and sulfur on the surface of analytical samples became uniform after high energy pre-spark discharge.

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Perchlorate ion forms insoluble ternary complex, [Ag (phen) ₂ClO₄], with Ag (I) in the presence of 1, 10-phenanthroline (phen). Simple and direct determination of perchlorate ion based on the formation of this ternary complex was investigated by conductometric titration. Recommended procedure is as follows; An aliquot of sample solution containing (6 34) mg of perchlorate ion is transferred into a 100 ml beaker. Two ml of 3 M acetate buffer solution is added to it and pH is adjusted to 5.0. The sample solution is diluted to a volume of 100 ml and titrated with 0.1 M Ag(phen)₂⁺complex standard solution (40% ethanol-water solution) at the rate of 0.20 ml/ min. The change of phen concentration up to 2.36 on the molar ratio of phen/Ag (I) in the standard solution had no interference with the determination of perchlorate ion at pH 4.85.8 (Fig. 2). When citrate, tartrate or oxalate buffer solution was used in place of acetate buffer solution, the large positive error was obtained. By this method, the determination of perchlorate ion was performed satisfactorily with relative standard deviation of less than 0.9% (Table 1). The effect of diverse ions on the determination was studied in detail (Table 2). The comparison of this method with tetraphenylarsonium chloride technique on the determination of purity for ammonium perchlorate was also investigated (Table 3). The obtained value of apparent solubility product (log K_sp') of this ternary complex was - 24.25 and the heat of reaction which was calculated from this value was 36.7 kcal/mol (Table 4).

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Since methods for the determination of minute amounts of tin were debatable, an application of atomic absorption spectrometry using graphite furnace was studied. As to the solution media for the atomization, a nitric acid solution is preferable to hydrochloric acid solution, and it must be free from perchloric and sulfuric acids. Interference induced potentially by aluminum, antimony, arsenic, tellurium, tartaric acid and citric acid could be prevented by the addition of adequate amounts of lanthanum nitrate. Moreover it increased the sensitivity for tin, and thus 2000 ppm of lanthanum was used as suitable concentration. As for the procedure, (21 0) μg of tin was coprecipitated with 10 mg lanthanum from an aqueous ammonia media, resulting in the separation of tin from unexpected interfering components. The method was applied to the analysis of tin in zinc and copper metals.

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Citric, lactic, urocanic and pyroglutamic acid (PCA) in cosmetic products were determined by high speed liquid chromatography employing a octadecylsilica (TSK-Gel, LS-410, 5μ, ) as a column packings and 1.0 M sodium sulfate aq. solution (pH: 2.2, adjusted with phosphoric acid) as a eluent. The recommended conditions for the analysis were as follows: column size; 4 mm i.d. ×250 mm, detector; UV spectrophotometer (210 nm), flow rate; 1.0 ml/min, column temperature; 25°C, eluent; 1.0 M sodium sulfate aq. solution (pH : 2.2). Surface active agentes, oils and fats in cosmetic products which strongly held in the octadecylsilica packings were eliminated by ion exchange pretreatment. Calibration curves were linear within a range of (40200) ppm for citric, lactic acid, (1030) ppm for PCA, (14) ppm for urocanic acid, respectively. Recoveries of four acids for known samples were satisfactory. By using this method, four acids in several commercial cosmetic products such as toilet waters and/or moisturlizing lotions were simultaneously determined without any intereferences.

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A simple and rapid determination method of copper (II) in the presence of other metal ions such as zinc (II), cadmium (II), cobalt (II), nickel (II), manganese (II) and iron (II, III) based on the dif ferece in the rates of ligand substitution reaction between 2-(2-thiazolylazo)-5-dimethylaminophenol (TAM) complexes and EDTA was studied. TAM and TAM complexes of these metal ions were solubilized by the addition of aqueous nonionic surfactant, Triton X-100, and the stopped-flow technique was applied for the rate determination. The procedure is as follows: Take a sample solution containing less than 18 μg/25 cm³ of copper into a 50 cm³beaker and add 100 mg ammonium peroxodisulfate to oxidize the ferrous ion to the ferric ion. After adjusting to pH 56 add 2 cm³ of 0.5 mol dm^-3 citrate solution and 10 cm³ of 1.73 × 10^-3mol dm^-3 TAM aqueous Triton X-100 solution. Add Kolthoff 's buffer and perchlorate to control pH at 7.6 and ionic strength at 0.1, respectively. Transfer the contents of the beaker into 50 cm³ volumetric flask and dilute it to the mark with water. Initiate reaction by mixing this solution with 2.0 × 10^-3 mol dm^-3 EDTA solution (pH 7.6, μ= 0.1) at 25°C, and record the absorbance at 563 nm as function of time (for 0.1 s). Copper (II) is determined from the difference of the absorbance between the initial absorbance and the constant value obtained at 0.03 s after the initiation of the reaction. Copper (II) up to 1 μg/50 cm³ can be determined even in the presence of Zn (II), Cd (II), Ni (II), Co (II) and Fe (II, III) with the error of less than 3%. The anion such as CH₃COO^-, NO₃^- Cl^-, Br^-, I^- and SO4₄^2-do not interfere.

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A decomposition method with ammonium sulfate for Al₂O₃, TiO₂ and Nb₂O₅ is presented. Al₂O₃ and TiO₂ were fused at 400 and 450°C, for 2 h and 1 h, respectivly, in the presence of ammonium sulfate (oxide/ammonium sulfate =1/20 in weight). The fused products were dissolved and extracted into 4N H₂SO₄ aqueous solution by warming on the water bath or gently boiling on asbestos. The degree of decomposition by fusion was confirmed from the amount of the oxides recovered in the following manner; with the aid of filter pulp, the residue was completely separated by filtration and washed thoroughly by hot water. To the filtrate was added ammonia water in order to precipitate aluminum and titanium hydroxide. The precipitates were ignited in platinum crucible at 1000°C and weighed in oxide form. Nb₂O₅ was fused at 400°C for 1 h in the presence of ammonium sulfate (niobium pentoxide/ammonium sulfate =1/10 in weight). The fused product was extracted with 20% tartaric acid aqueous solution. The degree of decomposition by fusion was confirmed from the amount of the oxide recovered as follows; after separation of the residue by a filter paper with the aid of filter pulp and washed thoroughly by 2% tartaric acid aqueous solution, freshly prepared 6% aqueous solution of cupferron was added to the filtrate and the precipitate formed was filtered immediately. The precipitate was ignited in platinum crucible at 1000°C and weighed as Nb₂O₅. The recovery of Al₂O₃, TiO₂ and Nb₂O₅ by the present method was (99.2± 0.4), (100.1 ± 0.2) and (100.1 ± 0.2) %, respectivly. It is concluded that Al₂O₃, TiO₂ and Nb₂O₅ could be completely decomposed with ammonium sulfate.

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The sensitivity enhancement of aluminum with nitrogen-containing compounds such as hexamethylenetetramine (hexamine), ammonium acetate, urea, ammonium chloride and ammonium.perchlorate was studied using the oxygen-sandwiched air-acetylene flame. In this flame, sensitivity for aluminum was about 40μg/ml/1% absorption. By adding one of the above reagents, sensitivity was enhanced 2 to 10 times greater than in the absence of reagents. To study mechanisms of the observed enhancement with these reagents, the formation of aluminum hydroxide, the distribution of size of mist and dry particles, and the properties of dry particles were examined by means of X-ray diffraction, electron probe X-ray microanalysis, thermogravimetric analysis and differential thermal analysis. Adding these reagenst, the following phenomena were observed: (1) the formation of aluminum hydroxide in the hexamine, ammonium acetate and urea solution was more rapid than in the ammonium chloride, ammonium perchlorate and standard solution; (2) the diameter of mist was more uniform than in the absence of these reagents; (3) the diameter of dry particles produced from the hexamine and ammonium acetate solution was smaller than that produced from urea and standard solution; (4) the dry particles produced from the hexamine, ammonium acetate and standard solution showed less association with chlorine than these produced from the ammonium chloride and ammonium perchlorate solution. In conclusion, the enhancement in sensitivity may be related to the formation speed of hydroxide, the diameter and other properties of dry particles, and process of dry particle formation in addition to increasing the reducing nature of the flame. It is probable that the enhancement with hexamine and ammonium acetate may involve formation speed of aluminum hydroxide and subdividing of dry particles. The enhancement with ammonium chloride and ammonium perchlorate may involve subdividing of dry particles. Processes of dry particle formation were also inferred from the present results.

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A line sample injector was attached to a conventional glass concentric nebulizer with a small volume (35 cm³) spray chamber. In order to prevent the sample from being diluted with carrier water, the sample was injected into a small air bubble (50μl) which was formed by lifting the entrance of the carrier tubing above water for a short time. When 40-μl samples were introduced, peak line intensities decreased to about 65% of those obtained by continuous nebulization, and detection limits of various elements were about 5 times higher than those of the conventional method. However, this method generally suffers from less matrix effects than the conventional method and allows to introduce solutions with higher salt and organic solvent concentrations. The relative standard deviations of the intensity measurements were about 4% in all the concentration ranges except near the detection limits.

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An extraction system of Zephiramine-thiocyanatocobalt (II) -chloroform was used as a pretreatment procedure for determination of cobalt by the graphite furnace atomic absorption spectrometry. When the aqueous/organic phase volume ratio(V_w/V_o) was 25ml/5 ml, the best extractability of the ion-pair was observed over the range of 4 M HCl to pH 8 when the concentrations of Zephiramine and potassium thiocyanate were more than 2 × 10^-3 M and 0.04 M, respectively. The established extraction procedure was as follows: To 20 ml or less amount of the sample solution containing not more than 0.7 μg of cobalt in a separatory funnel, add 2 ml of 2.5 M potassium thiocyanate solution and 2 ml of 5.0 × 10^-2 M Zephiramine solution. If necessary, adjust the pH to below 8 with hydrochloric acid. Dilute the solution to 25 ml with water, and add 5 ml of chloroform. Shake the mixture for ca.5min, and allow the phases to separate for ca. 15min. For the measurement of atomic absorption, the organic extract (20 μl) was injected into a graphite furnace and then dried (200 °C-30 s), ashed (930°C-60 s) and atomized (2800°C10 s) with an argon flow rate of31/min. When a sample solution taken was 20 ml for the extraction(V_w/V_o= 25ml/5ml), the linearity of the absorbance (240.7 nm cobalt line) vs. the concentration of cobalt was observed up to 0.7 μg/20 ml (35 μg/l) of cobalt. In this case the apparent sensitivity for 1% absorption was estimated to be 0.011μg/20 ml(0.55μg/l) of cobalt and the coefficient of variation(n=10) of this method was 2.0% for 0.5μg/20 ml(25μg/l) of cobalt. Numerous cations and anions gave no interference effect even when they were present in 10000 fold amounts (by weight) over cobalt. This method was applied to the analyses of cobalt in the copper mine drainage and commercial reagents of iron and nickel salts.

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Rapid determination of trace amounts of copper, iron and manganese in polyimide resins by graphite furnace atomic absorption spectrometry has been investigated. The standard solutions used were prepared as follows; after evaporating 1 ml of each stock solution (1000 ppm in nitric acid medium), the residue was dissolved in 100 ml of dimethyl formamide. The following procedure was used. Resins 08g were dissolved in (26) ml of dimethyl formamide, and an aliquot of standard solution of each element was added to it and diluted to 10 ml with dimethyl formamide. A 10μl of the solution was pipetted into graphite furnace atomizer and the atomic absorption signals were measured. The peak height and peak area methods were compared. The peak height values of copper, iron and manganese increased with increasing atomizing temperature, while the peak area values of the three elements approached to a constant value above 2300°C (Cu), 2400°C(Fe) and 2200°C (Mn). Calibration curves were linear in the range of 010 ng (peak area method) and05 ng (peak height method) for the three elements. The standard addition method was used in practical analysis. The standard deviation were (1.84. 9) % (peak area method) and (3.25.9) % (peak height method). The analytical results obtained by the proposed method agreed with those obtained by a dry ashing flame atomic absorption spectrometry. A single determination took about 10 min, which was about a twentieth of the time required by a dry ashing flame atomic absorption spectrometry.

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Halogeno or carboxylato groups in their triaryl- or trialkylantimony (V) derivatives have been determined by alkalimetry after their hydrolysis. The standard analytical process is as follows. About 0.2 mmol(70 150 mg) of the sample is taken into a 200 cm³ beaker, and is dissolved into 20 cm³ of acetonitrile. The mixture is boiled if the sample is hardly soluble. After the complete dissolution, it is diluted with 20 cm³ of water, and is kept for several min. The solution is then titrated with 0.1 M sodium hydroxide aqueous solution. Acetone, N, N-dimethylforrnamide, tetrahydrofuran, and dimethylsulfoxide can also be used in place of acetonitrile (N, N-dimethylforma mide solution should not be boiled). Satisfactory results could be obtained for 13 organoantimony compounds, such as dibromotriphenylantimony (V), diacetatotriphenylantimony (V), bis (benzoato) tris (p tolyl) antimony (V), dibromotrimethylantimony (V) etc. (The samples used were over 99.7% in their purity estimated from their carbon analyses). This method is conveniently applicable to check the composition of the samples of these compounds.

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A KBr-coated photocell has been evaluated as a detector of a non-dispersive vacuum ultraviolet (VUV) atomic absorption spectrophotometer for mercury. The photocell shows high quantum yield in the VUV region, and lower quantum yield in the UV region of longer wavelength. This characteristics of the photocell provides selective detection of the Hg I 185.0 nm line, which is more sensitive in mercury atomic absorption than the Hg I 253.7 nm line, and allows to build a non-dispersive measurement system. The sensitivity (1% absorption) and detection limit (concentration corresponding to S/N = 2) were 0.26 ng and 0.043 ng, respectively, using a 30 cm (length) absorption cell. The detection limit may be improved by the use of a logarithmic amplifier and by reduction of dark current in the system.

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