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Volume 28, Issue 9
Displaying 1-16 of 16 articles from this issue
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Yukio MINAMI, Toshiyuki MITSUI, Yoshikazu FUJIMURA1979 Volume 28 Issue 9 Pages 513-516
Published: September 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSEster compounds (ethyl maleate, monoethyl maleate, ethyl formate, butyl formate, isopentyl formate, pentyl acetate, ethyl acetate, methyl benzoate, methyl oxalate, dimethyl isophthalate, ethyl butyrate, ethyl propionate, ethyl hexanoate) were determined with good precision by atomic absorption spectrophotometry (A. A. S.). The recommended procedures are as follows : To 1 ml of each sample solution {(0.0353.482) mg/ml} is added 4 ml of hydroxylamine hydrochloride-sodium hydroxide solution (hydroxylamine hydrochloride 200 mg/ml and sodium hydroxide 120 mg/ml) and the mixture is warmed on a water bath for 5 min at 70°C. After cooling, 2 ml of hydrochloric acid solution (3 N), 2 ml of ferric chloride (Fe 3.3 mg/ml) and 5 ml of benzoic acid solution are added and the mixture is allowed to stand for 15 min. The mixture is filtered through No. 5 C Toyo Roshi filter paper. The filtrate is measured by A. A. S. Aluminum and copper ions interfered remarkably in the coexistence of (0.51.0) fold and more (metal/ethyl acetate, mol/mol) but potassium, magnesium, calcium, ethyl ether, acetone, acetic acid, aniline, nitrobenzene, propionaldehyde, phenol do not interfere up to 21 fold (compounds/ethyl acetate, mol/mol).View full abstractDownload PDF (571K) -
Yoshitsugu ODANAKA, Osami MATANO, Shinko GOTO1979 Volume 28 Issue 9 Pages 517-522
Published: September 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA method has been developed for the direct determination of methylated arsenicals [dimethylarsinic acid (DMAA) and methane arsonate disodium salt (MAA-2Na) ] and inorganic arsenicals [arsenite {As(III)} and arsenate {As (V)}] using the graphite-furnace atomic-absorption (GFAA) spectrometry system. A sample solution of a 10μl-aliquot was injected into graphite-furnace (Hitachi model 170-70 spectrometer), then dried at 100 °C for 60 s, charred at 620 °C for 30 s and atomized at 2800 °C for 5 s with measurement at 193.7 nm. Argon was used as the sheath gas of 3.0 l/min and purge of 0.15 l/min. Appreciable different sensitivity among DMAA, MAA, As (III) and As (V) was observed in a distilled water matrix alone. The DMAA absorbance showed the lowest sensitivity is approximately 1/31/4 of that of arsenate showed the highest. A remarkable signal enhancement was produced by adding representative alkali metal (LiNO3), alkaline-earth metals [Mg (NO3)2, Ca(NO3)2, Sr(NO3)2, Ba(NO3)2], iron family metals [Fe(NO3)3, Co(NO3)2, Ni(NO3)2], acids (HNO3, HClO4) and basis (LiOH, NaOH, KOH, RbOH, CsOH). By the addition of these coexisting reagents, especially in DMAA signals, improvement of sensitivity was noted up to (34) times, and the sensitivities of DMAA, MAA, As (III) and As(V) with each equivalent arsenic contents became similar. These coexisting reagents [NaOH, Ni(NO3)2] were applied to the determination of arsenicals in environmental materials (extracts of rat's blood, grape, river water and soil, and TLC extracts of these samples) which were extracted and isolated by a similar method to the previous reports {J. Agric. Food Chem., 26 (2), 505 (1978)}. Since the interference from extracts of grape and soil samples were completely eliminated by the addition of coexisting reagent (NaOH), concentration of arsenicals could be calculated directly from the calibration curve. Recoveries on the presence of coexisting reagent (Ni) of DMAA or MAA-2Na added to various samples were almost quantitative.View full abstractDownload PDF (1028K) -
Solvent extraction of molybdenum blue with tetradecyldimethylbenzylammonium chloride into chloroformKousaburo OHASHI, Choutaro SUZUKI, Katsumi YAMAMOTO1979 Volume 28 Issue 9 Pages 523-526
Published: September 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSSolvent extraction of molybdenum blue, which was formed by a reaction of phosphate with a mixture of molybdenum (V) (MO2O42+) and molybdenum (VI), was investigated spectrophotometrically. Molybdenum blue is extracted quantitatively into chloroform over the range of perchloric acid concentration from 0.31 to 0.71 M and over the range of tetradecyldimethylbenzylammonium chloride concentration from 6.00×10-2 to 1.32×10-1 M. The extracted species is very stable. The number of tetradecyldimethylbenzylammonium bound to one mole of molybdenum blue at 0.31 M HClO4 was found to be about three. An absorption spectrum of molybdenum blue extracted into chloroform (λmax 830 nm) is different from those of molybdenum blue (λmax 840 nm) in an aqueous solution and of molybdenum blue extracted into methyl isobutyl ketone (λmax 800 nm).View full abstractDownload PDF (579K) -
Sanae IKEDA, Junko MOTONAKA, Yasuo NAKABAYASHI1979 Volume 28 Issue 9 Pages 527-531
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSTwo coulometric titration methods for the determination of dithiooxamide by using a silver anode and a platinum cathode as the generator electrodes have been studied. One method is the direct determination method in which dithiooxamide is titrated with electrogenerated silver (I) ion in ammonia-ammonium nitrate electrolyte. The other method is the indirect determination method in which dithiooxamide is treated with iodine-carbon tetrachloride in alkaline solution and the iodide produced is titrated with silver (I) ion. Potentiometric end-point detection technique with a silver-silver sulfide or a silver-silver iodide electrode is used. Recommended procedures are as follows. Direct method : Measure exactly 5 ml of ( 10-410-3) M dithiooxamide into a 100-ml titration cell, add 5 ml of 2 M ammonia and 5 ml of 1 M ammonium nitrate, and adjust the volume to 50 ml with redistilled water. Titrate the solution coulometrically by the generating current between 0.965 and 9.65 mA so that the generating time may be within 5 min. Indirect method : Measure exactly 5 ml of (3×10-56×10-4) M dithiooxamide into a 100-ml titration cell, and add 2 ml of 5 M sodium hydroxide, 2 ml of (2×10-34×10-2) M iodinecarbon tetrachloride and 16 ml of redistilled water. Stir the solution for 5 min, add 3 ml of 5 M perchloric acid, and adjust the volume to 50 ml with redistilled water. Titrate the solution coulometrically by the generating current between 0.965 and 19.3 mA so that the generating time may be within 5 min. Good results were obtained for (66660)μg {(10-5 10-4) M} of dithiooxamide by the direct method and (18390) μg { (3×10-66×10-5) M} by the indirect method. The relative errors and the relative standard deviations were less than 0.2 %. The former method possessed an excellent selectivity, and the latter tended to be affected by concomitant compounds. But the sensitivity of the indirect method was better than the direct method.View full abstractDownload PDF (962K) -
Studies on the coprecipitation from homogeneous solution. XIV.; Studies on the coprecipitation by means of electron microscopy and diffraction methods. XIIKazuyoshi TAKIYAMA, Yuko ISHII1979 Volume 28 Issue 9 Pages 531-535
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSCoprecipitation of barium with lead sulfate from homogeneous solution by the use of sulfamic acid was studied from the viewpoints of analytical and crystal chemistries. Lead sulfate was precipitated in the solution containing a small quantity of barium, and then the precipitate dissolved in ammoniac EDTA solution was analyzed by the atomic adsorption spectroscopy. The coprecipitation of barium with lead sulfate was found to conform to the Doerner-Hoskins logarithmic distribution law and the distribution constant obtained was 2.33. The particles prepared from the same molar quantity of lead and barium were analyzed by electron microscopy and diffraction methods. In the process of precipitation the shape of particles changed from elliptic to rectangular, the elliptic resembling barium sulfate particles and the rectangular lead sulfate particles, respectively. Each reflection peak of X-ray diffraction of the precipitate finally prepared was found between the corresponding peaks of lead and barium sulfates, but that peak was not sharp-pointed because the barium and lead were not distributed homogeneously in the particles. The coprecipitation of barium with lead sulfate was used to measure the content of barium in water. This showed that one liter of the surface water of sea and river contained 0.15 and 0.01 mg barium, respectively.View full abstractDownload PDF (1005K) -
Tomosuke ISHIZUKI, Hiroko WADA, Genkichi NAKAGAWA1979 Volume 28 Issue 9 Pages 535-540
Published: September 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESS2-(2-Thiazolylazo)-5-sulfomethylaminobenzoic acid (TASMB), 2-(2-thiazolylazo)-5-dimethylaminobenzoic acid (TAMB), and 2-(2-thiazolylazo)-5-sulfomethylaminophenol (TASMP) were synthesized. TASMB and TAMB react with Cu2+, Ni2+, Co2+, Co3+ and Pd2+ from considerably low pH. TASMP reacts with various metal ions as well as other 2-(2-thiazolylazo) phenols. These reagents were used as the indicator in the nickel-EDTA titration. In the pH range of 47 the sharp color change from purple to yellow was observed at the equivalence point at 40°C for TASMB, and from bluish violet to orange at 55°C for TAMB. With TASMP the titration should be carried out at 80 °C as with 2-(2-thiazolylazo)-4-methylphenol (TAC). TASMB is an excellent indicator for nickel because of the fast color change, the clear color contrast, and the large solubility in water. The acid dissociation constants of TASMB (H2L) and TAMB(H2L+), and the formation constants of the nickel chelates were determined by spectrophotometric method (25°C, μ=0.1). TASMB : pk1=1.1, pk2=3.2, log KNiL = 4.8, TAMB {2% (v/v) dioxane} : pk1=1.7, pk2=3.3, log KNiL = 5.5. From the results of continuous variation method the nickel to ligand ratio in TASMB and TAMB chelates was 1 : 1. The small tendency to form a 1 : 2 chelate may contribute to the fast color change of TASMB in the nickel-EDTA titration.View full abstractDownload PDF (839K) -
Yutaka ASAHI, Mariko OHNISHI, Nobuyuki NAKAJIMA1979 Volume 28 Issue 9 Pages 540-544
Published: September 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSThe fluorescence reaction of steroids in concentrated sulfuric acid has been used for the quantitative determination. In this paper, the structure of the fluorescent product from hydrocortisone (I) in sulfuric acid-ethanol (7 : 3) is elucidated by spectroscopic and chromatographic methods to be 21-hydroxy-17-methyl-18-norpregna-4, 6, 8 (14)-triene-3, 20-dione (II).The structure of by-product is also proposed to be pregna-4, 9(11)-diene-3, 16, 20-trione (III) or pregna-4, 7 (8)-diene-3, 16, 20-trione (III'), in which the 16-enol contains a predominant tautomer.View full abstractDownload PDF (742K) -
Akiya NAKAMURA, Tamio KAMIDATE, Hideo IMAI, Hiromichi UEHARA, Yasuharu ...1979 Volume 28 Issue 9 Pages 544-549
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA K-band microwave cavity spectrometer of a Stark-voltage sweep type was constructed as a pollutant monitor. The spectrometer incorporated a Gunn effect microwave oscillator and a microwave bridge of magic-T. A gas absorption cell was a TE1, 0, nmode rectangular cavity resonator in which an internal Stark electrode was installed. Internal dimension of the resonant cavity is 6.5 mm in height, 13 mm in width and about 800 mm in length. The resonator was attached to an arm of magic-T. Spectrum of pollutant gas was obtained by continuous sweep of the Stark dc voltage supplied to the internal electrode. These devices made the spectrometer compact and highly sensitive. Various pollutant molecules which had electric dipole moment were detected at the concentration around a few hundreds ppm. These were sulfur dioxide, ammonia, acrolein and dimethyl sulfide. Specially, 0.2 ppm ammonia in nitrogen was detected. Dependence of peak absorption intensity on sample pressure was discussed. A calibration curve for ammonia in nitrogen base-gas showed good linearity in the concentration from 1 to 10 ppm under conditions that the oscillating frequency and the total sample pressure were 23.875 GHz and 0.8 Torr, respectively.View full abstractDownload PDF (1015K) -
Kiyoshi IMAMURA, Toru FUJII1979 Volume 28 Issue 9 Pages 549-554
Published: September 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA rapid, selective, and sensitive method for the determination of toluene, ethylbenzene, and xylene isomers at ppb level in ambient air by using mass fragmentography of gas chromatograph-mass spectrometer (GC-MS) is presented. The method was based on the continuous monitoring of the m/e 91 ion peak to diagnose the species of each compound, operating MS to set ionization voltage at 70 eV and collector slit width at 0.5 mm. The air samples were directly injected into GC-MS by a Teflon sample loop (3.0 ml), and separated on the column coated with 5% Bentone 34+5% DDP. The observed values of the mass fragmentogram revealed that the relative molar sensitivities of ethylbenzene, ο-, m-, and p- xylenes were 1.49, 1.10, 1.06, and 1.08, respectively when that of toluene is unitary, and these factors could be used for the determination of these compounds in atmospheric samples. The relative pattern coefficients of these four compounds, divided the pattern coefficients by that of toluene, were proportional to the relative molar sensitivities, and the proportional coefficient was 0.78± 0.01. The detection limits of toluene, ethylbenzene, ο-, m-, and p- xylenes were about 2.0, 2.0, 4.0, 3.5, and 3.0 ppb, respectively when sample volume was 3.0 ml. The method was applied to the determination of the ambient air by every 15 min sampling, and the average concentrations of toluene, ethylbenzene, ο-, m-, and p- xylenes were 32, 5.3, 5.5, 8.4, and 4.3 ppb, respectively. The analytical time needed for one sample was about 10 min.View full abstractDownload PDF (937K) -
Akiyoshi SUGIMAE1979 Volume 28 Issue 9 Pages 555-560
Published: September 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA method was described for the determination of trace elements (Be, Zn, Pb, Cd, Ni, Mn, Fe, Cr, V and Cu) in water sample. The plasma operating conditions employed were as follows: RF power; 1.6 kW, Ar flow rate; 11 l/min (coolant), 1.3 l/min (plasma) and 1.0 l/min (carrier), observation height in plasma; 16 mm above coil and nebulizer; coaxial and pneumatic nebulizer. Spectral intensity was reduced steadily with increasing concentration of concomitants up to 2% (20% reduction). This interference was probably caused by change in physical properties of the nebulized solution. Water samples contain various concomitants and vary widelyin composition. To assess the extent of the physical Interference occured in actual samples, several of river water samples were analysed by the standard addition method; aqueous standards were usually used for calibration. The results obtained by using aqueous standards were lower than those obtained by the standard addition method. In the worst case, where the concentration of concomitants was very high (9.6%), the values were lower by 40%. A correction for the interference was required if concomitants were present at the concentration exceeding about 0.5%. This correction involved monitering the concentration levels of concomitants in water samples. Detection limits were in the range of (0.34) ng/ml for most elements studied. The inductivery coupled plasma-optical emission spectrometry could be successfully used for the analysis of water samples.View full abstractDownload PDF (913K) -
Susumu NAKASHIMA1979 Volume 28 Issue 9 Pages 561-563
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA rapid and precise method is described for the separation and determination of arsenic in natural sea water. The procedure is as follows: Add 2 ml of iron (III) solution (5 mg ml-1) to 250 ml of sea water in a 300-ml beaker. Adjust the pH to 89with aqueous ammonia solution, and stir the solution for 15 min. After adding 1 ml of sodium oleateethanol solution (1 mg ml-1), transfer the contents of the beaker to a flotation cell (24×4.8 cm i.d.) fitted with a sintered-glass filter (No.4). Pass air at 50 ml min-1 from the lower end of the cell about 1 min. Suck off the mother liquor through the sinteredglass disk. Add 5 M hydrochloric acid to dissolve the precipitate, collect the filtrate by suction in a 10-ml calibrated flask and dilute to 9 ml. Add 0.5 ml of 20% (w/v) potassium iodide solution into the flask prior to analysis and dilute to the mark with water. Transfer 1 ml of 5 % (w/v) sodium borohydride solution into a hydride generating cell. Inject 1 ml of sample solution containing less than 0.10 μg of arsenic into the cell. Sweep the arsine thus generated into the long absorption cell (60×1.2 cm i.d.) with nitrogen so that it is atomized in the nitrogen-hydrogen flame and measure the absorption signal of arsenic by atomic absorption spectrophotometry. The potassium iodide pretreatment after the separation eliminated suppressive effects by diverse ions such as Cu2+, Se4+ and Ni2+ in the determination of arsenic. In the analytical process, mean recoveries were (99101) % for arsenic (III, V) added to natural sea waters. The relative standard deviations of 7 replicate analyses of sea water samples were less than 3%.View full abstractDownload PDF (559K) -
Hiroshi NISHIDA1979 Volume 28 Issue 9 Pages 563-565
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSTrithiocyanuric acid (1, 3, 5-triazine-2, 4, 6-trithiol, TTCA) formed an insoluble brown precipitate with copper (II). This precipitate was dissolved in water in the presence of Tween 20 (polyoxyethylene sorbitane monododecanoate) and gave an absorption maximum at 360 nm. Then the yellow color development was applied to the spectrophotometric determination of copper. Recommended procedure is as follows: To less than 200 μg of copper in an acidic medium, add 4 ml of Tween 20 solution (0.1 g ml-1) and 2.0 ml of TTCA solution (0.003 g ml-1). Adjust pH to 3 with sodium acetate solution (0.25 M) and dilute to 25.0 ml with water. Measure the absorbance at 390 nm against the reagent blank. Beer's law held for (5200) μg of copper in 25 ml volume with the molar absorptivity, ε390 = (7.90 ± 0.05)× 103 cm-1 mol-1 l, being Sandell's sensitivity, (8.1±0.1)× 10 -3 μg cm-3. Less than 2 mg of Al (III), Ca (II), Ba (II), Cd (II), Ni (II), Co (II), Mn (II), Fe (II), Cr (III), As (III), Zn (II) and 1 mg of Sn (II) did not interfere. Less than 2 mg of Fe (III) was masked by reduction with hydroxylamine hydrochloride. Interferences from less than 2 mg of Pb (II) and Bi (III) were removed by coprecipitation with barium (II) as thier sulfates and with iron (III) as their hydroxides from its ammoniacal solution, respectively. Interference from less than 0.1 mg of Pd (II) was removed by the determination of copper from a difference between the absorbances obtained with and without the addition of EDTA for masking of copper.View full abstractDownload PDF (600K) -
Sumio YAMASAKI, Hiroki OHURA, Kouji YANO, Issei NAKAMORI1979 Volume 28 Issue 9 Pages 566-568
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSUnder suitable high chloride ion concentration in an acidic solution {(37) MH2SO4}, chlorate ion reacts with chloride ion to form chlorine which reacts quantitatively with Methyl Orange to decrease the absorbance (at 504 nm). Therefore, the decreased absorbance of Methyl Orange by this reaction was used to determine the chlorate ion concentration. Analytical procedure is as follows. Mix 1 ml of the sodium chlorate solution {(1×10-51×10-4)M} with 10 ml of 6.3×10-3 g/l Methyl Orange solution which contains 6 M sulfuric acid and 0.3 M chloride ion. After shaking for about 20 min, measure the absorbance at 504 nm against the reagent blank. The molar absorptivity of Methyl Orange is 4.63×104 l mol-1 cm-1 at 504 nm and is constant at room temperature for at least 2 days. Less than 5×10-3 M of Mg2+, Zn2+, Co2+, Ni2+, Pb2+, Al3+, Mn2+, Fe3+, Cu2+ and of SO42-, CO32-, PO43-, F-, ClO-, ClO2-, ClO4- do not interfere with analysis, where in the solution containing ClO-, ClO2-, ClO3- and ClO4-, the chlorate ion can be determined after reducing ClO- and ClO2- with KBH4.View full abstractDownload PDF (372K) -
Noriko FUKUDA, Hiroshi ITOH, Akira TSUKAMOTO, Hiroshi TAMARI1979 Volume 28 Issue 9 Pages 569-572
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSGas chromatographic determination of a small amount of hydrogen cyanide in exhaust gases was studied by using the flame ionization detector and a precolumn. This method is based upon the findings that propane and hydrogen cyanide are 10:1 in sensitivity to FID. The chromatographic conditions are as follows: main analytical column packing, Porapak Q80/100 mesh; column size, 3m×4 mm i.d., glass; column temperature, programmed to raise 30°C to 50°C at 2°C/min and 50°C to 200°C at 5°C/min; carrier gas, nitrogen; calibration gas, propane. Exhaust gas sample is collected in an evacuated 1 liter sampling bottle, and is concentrated by passing it through the precolumn (a glass tube packed with Porapak Q80/100 mesh) in dry ice acetone bath. Then, the trapped gas sample is injected to the GC by heating the precolumn. The peak of HCN which appears between those of ethane and propylene, is separated by 9 min of retention time from the former and by 2 min from the latter when a 3 m column is used. A 2 m column is not enough to isolate it from them. Other interfering gases including inorganic ones have not been detected by FID. The concentration of HCN is calculated from the ratio of the peak area of the sample to the calibrated peak area of standard propane gas. The lower limit of determination of hydrogen cyanide is 0.1 ppm when 1 litter of the gas is sampled. This method can be applied not only to the determination of exhaust gases but also to that of ambient gaseous sample.View full abstractDownload PDF (679K) -
Bunshiro KOMINAMI, Shin-ichiro OKAWA, Akira KAWASE1979 Volume 28 Issue 9 Pages 572-574
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESS1-(2-Benzothiazolylazo)-9-phenanthol (TAP) reacts with a small amount of nickel in, the presence of a surface-active agent, Triton X-100, to form a soluble complex. The optimum conditions for spectrophotometric determination of nickel using the complex and the preventation of interference with the diverse ions were studied. The TAP-nickel complex has two absorption maxima at 555 and 590 nm and the reagent blank has it at 480 nm. The maximum absorbances are constant in the pH range from 6.0 to 7.5. Beer's low is obeyed up to 18.0 μg/25 ml of nickel and the apparent molar absorptivity of the complex is about 5.5×104 l mol-1 cm-1, based on the calibration curve. The combining ratio of nickel and TAP in the complex is shown to be 1: 2 by the molar ratio method and the continuous variation method. The proposed procedure is as follows: To the sample solution containing 10 μg of nickel in a 100 ml beaker, add about 5 ml of sodium acetate and borate buffer (pH 6.8) and 1 ml of the Triton X-100 (0.2g/ml) solution. Then, control the total volume from 15 to 20 ml with water, and adjust to pH 7.0±0.2 with 0.1 M sodium hydroxide or 0.1 M hydrochloric acid. Add 0.7 ml of 10-3M TAP-dioxane to the solution, and heat the solution on a boiling water bath for about 10 min, and cool. Transfer the solution into a 25 ml volumetric flask and dilute it to the mark with water. Measure the absorbance at 590 nm against the reagent blank or water. The determination gives a positive error in the presence of cobalt (II), copper (II), zinc, palladium (II), silver, cadmium or mercury (II), and gives a negative error in the presence of each of many kinds of ions, which are precipitated at pH 7.0±0.2. In order to remove the interference of those ions, solvent extraction of nickel dimethylglyoximate in ammoniacal tartarate solutions, masking of the colored interfering ions with EDTA were studied, and good results were obtained. In addition, nickel in metallic copper was determined successfully by this method.View full abstractDownload PDF (611K) -
Masakazu DEGUCHI, Takashi HAMAMURA1979 Volume 28 Issue 9 Pages 575-577
Published: September 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSPalladium (II) is quantitatively extracted from an aqueous solution at pH 5.56.0 with thiothenoyltrifluoroacetone (STTA) in xylene as a colored complex. The excess STTA in xylene can be removed by washing with alkaline solution, the palladium (II)-STTA complex shows an absorption maximum around 410 nm. The calibration curve is linear over the range of 030μg of palladium (II) in 10 ml of the organic phase. The coefficient of variation on the absorbance for 20μg of palladium (II) is 0.50%. The molar absorptivity is 3.7×104l mol-1cm-1. The molar ratio of palladium (II) and STTA is estimated to be 1: 2 by the continuous variation method. Copper(II), cyanide(I) and sulfide(II) interfere even when the amount is 1/10 times that of palladium (II). The sensitivity of this method is superior to the previous STTA method (by Rangnekar, et al.). An analytical procedure is as follows. A sample solution containing less than 30 μg of palladium (II) is taken. Five ml of acetate buffer solution is added to adjust the pH of the solution to 5.8±0.2. The volume is made up to 50 ml with water, and 10 ml of 2.1×10-4M STTA in xylene is added. After shaking for 5 min, the aqueous phase is removed and the organic phase is washed with 10 ml of borax-NaOH buffer solution (pH 11.5) by shaking for 1 min. Then the absorbance of the organic phase is measured at 410 nm against the reagent blank.View full abstractDownload PDF (498K)
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