The nmr spectrum was coded numerically into G and S values so as to prepare the file searching system for the structure identification of organic compounds. Here, G stands for the center of gravity of the whole spectrum and S for the standard deviation of each signal to the center (Equations 1 and 2, respectively). The two values of each of 232 nmr spectra of various compounds were stored in the computer. The file searching for the unknown compound was carried out by comparing the spectrum of the compound with the store. The result of the search proved fairly good usefulness of this method. Even in case that the molecular formula was uncertain, proper structure was reached in all cases - 72% of the tests gave unique answer of correct structure, 1% the correct structure plus three noises, the other 27% the correct structure plus one or two noises (Table IV). In the case when the molecular formula was known, the probability of finding unique answer of correct structure by this method was found as 89% (Table VII).

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In a series of quantitative determination of drugs by atomic absorption spectrometry, the authors attempted indirect determination of anthranilic acid by the extraction of its insoluble cobalt (II) chelate with MIBK in the presence of bathophenanthroline from phosphate buffer solution of pH 6.3. Anthranilic acid is determined indirectly by measuring cobalt in MIBK phase by atomic absorption spectrometry. Measurements were made with a Hitachi model 207 atomic absorption spectrophotometer, using air-acetylene flame. The conditions are : wavelength 2407Å (Co) ; slit width 0.18 mm; lamp current 15 mA; air flow rate 12 l/min and acetylene flow rate 2.0 l/min. It was found that anthranilic acid takes at least two times moles of cobalt and ten times moles of bathophenantholine. The calibration curve obtained was shown to be linear in the range of (322)μg/ml and the recovery was 99.5%. The species extracted with MIBK is considered to be a mixed ligand complex of Co(II), anthranilic acid and bathophenanthroline and three components have been identified by means of paper partition chromatography and the composition has been determined by the continuous variation method.

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2, 3-Dimethyl-5-hydroxyquinoxaline (5-OH-DMQx) and 1-hydroxy-6, 7, 8, 9-tetrahydrophenazine (1-OH-Tphz) have been synthesized. The acid dissociation constants of these ligands and the stability constants of their metal chelates have been measured in 50% (v/v) water-ethanol solution. The values obtained have been compared with those of 5-hydroxyquinoxaline and 2-substituted oxine metal chelates. The pK_OH values of 5-OH-DMQx and 1-OH-Tphz are 9.98 and 10.01, respectively. These values are considerably larger than the corresponding constant of 5-hydroxyquinoxaline, 9.29.
As to the metal chelate stability constants, (a) the metal chelate stability order is as follows : 5-OH-DMQx; log K₁ Cu>Zn>Co>Ni>Cd and logβ₂ Cu>Co>Zn>Ni>Cd. 1-OH-Tphz; logK₁ Cu>Zn>Co≈Ni>Cd and logβ₂ Cu>Co>Ni≈Zn>Cd. (b) the stability constants of these metal chelates are smaller than the corresponding constants of 5-hydroxy-quinoxaline, regardless of the value of pK_OH with the exception of the Zn-chelates. (c) The difference of the stability constants among Co-, Ni- and Zn-chelates is less than 0.4 log unit. The behavior of the stability constants of 5-OH-DMQx and 1-OH-Tphz indicates the similar tendency to that of 2-substituted oxine metal chelates. Accordingly, the stability constants of these metal chelates have been explained in terms of steric hindrance.

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For the analysis of the samples which cannot be dealt with routinely or for which calibration curves are not yet available, a formula of the x-ray intensity is useful. However, the formula must be modified by taking the primary radiation from the x-ray tube into consideration. To do this, the continuous primary radiation was assumed to be formed of a few representative spectral lines with the wavelengths, one near the peak position of Bremssrahlung, two the one of the characteristic spectra from the target of x-ray tube, i.e., WL_α1 or WL_β1 in W-target and CrK_α1 in Cr-target, and three that of the absorption edge corresponding to the spectrum to be measured. Relative contribution of the primary radiation to the secondary radiation at each of these spectral lines was evaluated and substituted for the term of the distribution of the primary radiation. The x-ray intensity formula was thus simplified. If the relative contribution and the constants which depend on the spectrum of the element in question and the instrumental condition were obtained for various elements, the simplified x-ray intensity formula is easily applicable to the quantitative analysis without the calibration curve prepared with the standard samples of similar composition. As examples, relative contribution and constants were experimentally obtained for CuK_α, FeK_α, TiK_α and SnL_α, and applied to the analysis of copper alloy, aluminum alloy and white metal. Not small error was observed in the determination of the constituent less than 1%, however, this method is simple and useful for the determination of the component higher than 1%.

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Oxidation behavior was studied on amorphous carbon and carbon in uranium monocarbide when lead (IV) oxide, copper (II) oxide and barium sulfate were used as the oxidizing fluxes in helium. The amorphous carbon and the carbon in the carbide were completely extracted with lead oxide in 5 min at 1000°C and in 8 min at 700 and 500°C, respectively. Carbon in two samples was quantitatively extracted at 1000°C with copper oxide in 8 and 5 min, and with barium sulfate in 7 and 5 main, respectively. The rate of extraction of carbon with copper oxide decreased with decreasing temperature. It was found that the mixing ratio of the oxidizing flux to the amorphous carbon or carbide gave effect on the recovery of carbon. The conventional capillary-trap method which is used for the determination of carbon has a disadvantage that, when carbon dioxide is caught in a cold trap (liquid nitrogen), oxygen is also trapped. This disadvantage was eliminated when a stream of helium was used in place of oxygen. Carbon in the sample can be determined with lead oxide, copper oxide or barium sulfate by extracting carbon dioxide at 1000°C for 10 min.

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A method for indirect determination of anion was investigated by liquid chromatography using a hydrogen type cation exchange column {resin : Hitachi-2613, (17±2) micron; column : 500×9 mm i. d.; eluent: water} and a flow coulometric detector. In order to determine indirectly the anion, the cation to be the counter ion of an anion was exchanged with hydrogen type cation exchange resin, and the hydrogen ion in column effluent reacted with p-quinone at the constant voltage of +0.45 V vs. Ag-AgI was determined by measuring coulomb in the reduction to hydroquinone. The retention volume (V_r) of the anions to form the strong acids by ion-exchange, such as chloride, nitrate, sulfate and dodecylbenzenesulfonate ions was about 12.5 ml. The V_r of the anions in the case of weak acids showed lower values than that of the strong acids, as follows; 13.0 ml for oxalate ion, 14.2 ml for phosphate ion, 14.5 ml for sulfite ion, 18.4 ml for floride ion, 19.5 ml for formate ion, 23.3 ml for acetate ion and 29.1 ml for carbonate ion, respectively.
The linear relationship was obtained between the V_r of the anions and the primary dissociation constant (pK₁) of the acids librated by ion exchange. The eluting process was considered as a partition chromatography based on ion exclusion. The calibration curve for sulfate ion was obtained with good linearity for the range of 5 to 1000 μg/ml, and the detection limit was 0.14μg/ml. The reproducibility on the chromatogram area of 100μg/ml sulfate ion was±0.69%.

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2-(2-Imidazolylazo) -4-methylphenol (2-IAC), 2-(4, 5-dimethyl-2-imidazolylazo)-4-methylphenol(2-MIAC) and 2-(4, 5-dimethyl-2-imidazolylazo)phenol(2-MIAP)were synthesized. The acid dissociation constants of these reagents were determined spectrophotometrically in 20% (v/v) dioxane at μ=0.1 and at 25°C : the values of pk₁ were 3.68, 4.65 and 4.50, and pk₂ 9.22, 9.62 and 9.40 for 2-IAC, 2-MIAC and 2-MIAP, respectively. The dissociation of imido group in imidazole was not observed at a pH below 12. The formation constants of copper and nickel chelates were determined in 20% (v/v) dioxane at μ =0.1 and at 25°C : logK_CuHA were 11.8, 12.4 and 12.5, logK_NiHA 8.95, 9.75 and 9.53, and log K_Ni(HA)2 8.70, 9.88 and 9.61 for 2-IAC, 2-MIAC and 2-MIAP, respectively. The formation constants are smaller than those of 2-(2-pyridylazo) -4-methylphenol (PAC), but somewhat larger than those of 2- (2-thiazolylazo) - 4-methylphenol (TAC). In the case of imidazolylazo compound the pyridine-like nitrogen in imidazole may co-ordinate with metal as in the case of pyridylazo compound or thiazolylazo compound. However, the nature of the nitrogen in imidazole might be somewhat different from that of pyridine or thiazole due to the presence of resonance between pyridine-like nitrogen and pyrrole-like one.
2-IAC, 2-MIAC or 2-MIAP could be used as an indicator for nickel-EDTA titration in the pH range between 5 and 8. This pH range is wider than that for TAC. Addition of a small amount of 1, 10-phenanthroline improved markedly the rate of color change at the equivalence point, and the titration could be done at 50°C. These indicators could be used for copper-EDTA titration as well as 4- (2-thiazolylazo) resorcinol (TAR).

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Methamphetamine hydrochloride in a methamphetamine hydrochloride and ephedrine hydrochloride mixture was determined indirectly by atomic absorption spectrophotometry of bismuth, the recommended procedure is as follows : A sample is dissolved in water, to which 1 ml of 7% HCl, and 1 ml of KI-BiCl₃ aqueous solution (7% KI solution saturated with BiCl₃) are added. The total volume of the solution is brought to 10 ml with water. The solution is allowed to stand for 30 minutes, and filtered. To one ml of the filtrate is added 1 ml of conc. HCl, and it is diluted to 25 ml with water, and then bismuth is determined by atomic absorption spectrophotometer. The respective presence of 0.04 times NaCl, 0.21 times Ca ²⁺, 0.20 times Mg ²⁺, 2.04 times Al ³⁺, 2.05 times K ⁺, 10.97 times glucose, 7.3 times ephedrine hydrochloride did not interfere the determination, whereas Na₂S₂O₃ interfered at the copresence of 0.41 times. The interference of metal ion and Na₂S₂O₃ on the determination of methamphetamine hydrochloride were eliminated by the extraction of methamphetamine from the basic aqueous solution into chloroform. Determination limit for the methamphetamine hydrochloride is 16 μg/ml.

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In the usual determination of micro amount of oxygen less than 10 ppm in nickel and cobalt, more than 2 grams of the sample is necessary because of the sensitivity of the usual method and of the influence of the blank values from the graphite crucible. However, such a large amount of the sample often gives inaccurate results and incomplete extraction when it is analysed by the conventional method of iron bath and dry crucible. In this paper, a new method using the carbon chips is proposed. The apparatus used in this study was Rigo analyzer for gases in metals S. H. O. II (sensitivity : 0.0055 mg/ mm Oil). The surface of sample was electropolished.
The recommended procedure is as follows : Carbon chips{(1620)mesh}, 2grams, is previously placed in the crucible and degassed for 5 hours at 2300°C. After degassing, the crucible temperature is lowered to the gas extraction temperature, 1750°C for nickel and 1700°C for cobalt, respectively, and then the sample is added to the crucible and gases are extracted and collected for 5 minutes. Before next sample is added to the crucible, carbon chips, 0.5 gram, is added to the crucible and degassed for a few minutes at 2000°C. Coefficient of deviation of this method was 5.6 (%) for electrolytic nickel (0 : 7.6 ppm), 18.6(%) for zone melted nickel (0 : 2.2 ppm) and 9.2(%) for zone melted cobalt (0 : 7.5 ppm).

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The spectrophotometric method for the determination of Fe (III) and Al (III) by using ο-hydroxyhydroquinonephthalein (HyPh) was devised and those metals in the presence of each other were also determined. To the solution containing less than 3.3μg of Fe (III), 3.0 ml of phosphate buffer (pH 8.8) and 1.0 ml of 5.0×10^-4M HyPh methanol solution were added and the whole volume was made up to 10 ml with distilled water. The solution was kept at 60°C for 30 minutes and then cooled for 15 minutes and then, the absorbance of it was measured at 605 nm or 620 nm taking the distilled water as the reference. Determination of Al(III) was carried out in the same manner as above with a slight modification that the reaction mixture was left to stand at (2025)°C for 20 minutes and the absorbance was measured at 530 nm against the reagent blank. The concentration of Fe (III) in the presence of Al (III) was determined by using the absorbance at 620 nm against distilled water. The calibration curves were linear in the range of 0 to 3.3 μg/ 10 ml of Fe (III) and 0 to 3.2 μg/10ml of Al(III). According to the Sandell's expression, the sensitivities were 0.0003 μg/cm²(605nm), 0.0004 μg/cm²(620nm)of Fe(III)and 0.0002μg/cm² (530nm)of Al(III) for an absorbance of 0.001, respectively.

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The quenching of uranyl fluorescence by Tl (I) was applied to the thallium determination. Lifetime and intensity of uranyl fluorescence in the absence and presence of Tl(I) were investigated in various acid media. In phosphoric acid solution, the fluorescence lifetime is the longest, and its intensity is also the strongest among the acid solutions used in the present work. In phosphoric acid as well as in sulfuric acid, this quenching action, which is caused by a collisional deactivation between excited uranyl ion and Tl (I) ion and is diffusion-controlled process, obeys the following Stern-Volmer relation:
I_o/I-1=τ_o/τ-1=KC=τ_ok_qC,
where I and τ are the fluorescence intensity and lifetime, and the subscript ₀ refers to the absence of Tl(I), k_q, C and K being the rate constant for the collisional deactivation process, the concentration of Tl(I) and the quenching constant, respectively. Tl(I) can be determined by using the plot of τ_o/τ- 1 (or I_o/ I-1)against C as a working curve. As its slope(K) is equal to τ_ok_q, phosphoric acid was the most appropriate media for the determination of small amounts of Tl (I). Dependence of the quenching constant on the concentration of phosphoric acid and temperature was shown in Fig. 1. In the determination of Tl (I), measurement of the lifetime was made with solutions containing 10 mM uranyl sulfate and 1M phosphoric acid at 25°C. Under these conditions, the working curve was linear in the concentration range of T1 (I) between 0.2 to 400μM. A satisfactory precision was obtained for Tl (I) in the concentration range of 0.5 to 400μM. The sensitivity of this method is comparable to a sensitive absorptiometric method. In the present method, the temperature of the specimen must be kept constant, and Ag (I), Fe (II), (I), Sn (II) and halogen ions strongly interfere the determination by the strong quenching action. The interference with Fe (II), Hg (I) and Sn (II), however, can be eliminated by oxidizing them to the higher oxidation state.

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The present work was undertaken to elucidate the spectrophotometric property of gallium-Chromazurol S (CAS, H₄L) complex by the modified equilibrium concentration method.
The equilibrium constant, (K₁), of the 1:1 complex formation reaction was given by the equation containing the molar absorptivity, (ε₁), of the complex as an unknown. It was necessary to solve the equation with two unknowns (K₁, and ε₁), obtained from the measurement of the absorbance at various pH's. These values were graphically obtained by means of the succesive apporoximation. The equilibrium constants of the 1:2 and 1:3 complex formation reactions were also obtained by the similar method. This method is applicable to the determination of composition and formation constant of stable complexes such as the gallium-CAS complex even when the absorbance of the reagent varied with the variation of pH. Gallium and CAS formed the 1:1, 1:2 and 1:3 complexes with the absorption maxima at 572nm (pH below 3), at 547 nm (pH above 3) and at 600nm (in the presence of an excess CAS), respectively. The formation constants of the complexes were calculated to be K(MHL)=1.2×10¹³, K[M (HL)₂]= 7.3×10¹², and K[M (HL)₃]=5.7×10¹¹ (25°C, ionic strength: 0.10), respectively. Beer's law did not hold for the calibration curves of gallium obtained by the measurements of the absorbances at 547 nm.

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A new method based on the difference in the contents of menthofuran and cineol has been developed for the discrimination of the species of peppermint oils by thin-layer chromatography. Thin-layer chromatography was performed with a commercially available silica gel plate (spot film, Easteman Kodak Co.). The solvent system used was a benzene-methyl acetate mixture (95 : 5 v/v). An intense color appeared by spraying 5% solution of vanillin in concentrated sulfuric acid. The location of menthofuran and cineol was easily identified on the plate not only by their R_f values but also by their colors. The detection limit of menthofuran and cineol visualized on the plate was to be 0.3μg and 5μg. Since the contents of menthofuran and cineol were (110)% and (610)% inM. piperita, when 0.5 to 1.0 mg of peppermint oils was subjected to analysis, menthofuran and cineol can be detected as visual spots on the plate, but these species in M. arvensis oil were not detectable. The amount of menthofuran in M.piperita oil decreases gradually during the storage at a room temperature. However, the amount of cineol is not affected. It was found that the method based on the quantity of menthofuran and cineol can be used for the identification of species of peppermint oils.

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Conditions for atomic absorption measurement of cadmium in dust jar were examined, and following procedures were chosen. A sample was dissolved in water, residue was separated by filtration (through No. 5C Toyo Filter). The solution was evaporated until dryness and the original residue was ashed for (89) hrs at 450°C in an electric furnace. Both samples were dissolved in nitric acid (30%, 10 ml) and then hydrogen peroxide (5%, 2 ml) was added. Samples were stored in 50 ml color comparison tubes.
Take 20 ml of sample (containing less than 2 μg of cadmium in 20 ml) into a 100 ml separatory funnel. Add 2 ml of 30% ammonia citrate, 2 ml of 40% ammonium sulfate solution, (56) drops of 0.1% thymol blue solution (neutralization indicator) to the sample and then pH of the solution was adjusted to 9.5 with (1 : 1) ammonia solution. Add 2 ml of 10% potassium cyanide solution and 2 ml of 3% sodium diethyldithiocarbamate (DDTC) solution and let it stand for about 5 minutes after stirring. Shake the solution vigorously for (23) minutes after adding 10 ml of methylisobutylketone (MIBK) and let it stand for 10 minutes. Separate the MIBK phase, and measure the cadmium concentration in the MIBK with an atomic absorption spectrophotometer. The optimum conditions for HITACHI 207 atomic absorption measurement were found to be the following : wavelength 228.8 nm, hollow cathod lamp current 5 mA, slit width 0.18 mm, height of light beam above burner 8 mm, air pressure 1.8 kg/cm², air flow rate 13.0l/min, acetylene pressure 0.5 kg/cm², and acetylene flow rate 2.0l/min.

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The column conditions and the reaction conditions for the separation of non-volatile organic acids were studied by gas chromatography. Non-volatile organic acids was first converted into suitable volatile derivatives prior to gas chromatography. Two different methods for esterification were investigated following; (1) acid mixture containing(56) mg of each acid were heated with 2 ml of 5% HCl-methanol for 4 hours at 55°C on a water bath, (2) acid mixture containing (56)mg of each acid were refluxed with 2 ml of 5%HCl-methanol for 4 hours. The former method gave better recoveries of the organic acid esters than the latter. One milliliter of deionized water was added to the esterified solution, then this solution was shaken 4 times with 2 ml of chloroform for 3 minutes in a 10 ml separatory funnel. The extracts were dried over anhydrous sodium sulfate, filtered and diluted to 10 ml with chloroform. When maleic acid was esterified, two peaks were detected. The retention time of one peak corresponded to that of the authentic dimethyl maleate, while the retention time of the other corresponded to that of dimethyl fumarate. This may be caused by cis-trans isomerism. Two peaks were also detected in keto acids such as pyruvic acid and α-ketoglutaric acid, probably owing to tautomerism. Various stationary phases were tested for the separation of organic acids. The organic acid methyl esters investigated here could be separated on both NPGS and FFAP column. Column temperature was programmed to rise from 100 to 220°C at a rate of 7.5°C/min.

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In the atomic absorption spectrometric determinations of copper and iron using acetylene-air flame, interferences by various alkali salts were observed. For the establishment of optimum analytical conditions avoiding these interferences, effects of such parameters as concentration of alkali salts, distance from burner head and acetylene flow rate were studied.
In the determination of copper, absorption at 324.7 nm was enhanced in the presence of 0.01M of NaCl when the sample solution was nebrized into fuel-rich flame {acetylene flow rate was (2.02.5)l/min} and the absorption was measured at 6.0 mm of the distance. No further enhancement was observed at the higher concentration of NaCl. For the determination of copper, measurement should be carried out at longer distance from burner head (more than 10.5 mm), in order to eliminate interference by alkali salts and absorbance change by acetylene flow rate. In the determination of iron, absorption at 248.3 nm was enhanced in the presence of 0.02M of alkali chloride when the sample solution in 0.02 N of sulfuric acid was nebrized into fuel-rich flame (acetylene was more than 2.4 l/min) and the absorption was measured at 15.0 or 25.0 mm. The order of degree of the enhancement was LiCl>NaCl>KCl>RbCl>CsCl. For the determination of iron, measurement should be carried out at shorter distance from burner head (6.0 mm) using fuel-lean flame (less than 1.9 l/min), in order to eliminate interference by alkali salts and obtain higher sensitivity.

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