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Volume 30, Issue 6
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Atsuo NAKAE, Kenji MANSHO, Kazuro TSUJI1981 Volume 30 Issue 6 Pages 353-357
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSMono-(MEA), di-(DEA), tri-(TEA), N-methyl-(Methyl EA), and N, N-diethylethanolamine (Diethyl EA) were separated and determined by high speed ion-exchange chromatography with a post-column derivatization method. The capacity factor of alkanolamines was affected by pH and sodium ion concentration of the eluent. The post-column derivatization for the detection of alkanolamines in the column effluent involves the chlorination of alkanolamines reacting with hypochlorite to form chloramine derivatives, followed by the selective destruction of the excess hypochlorite by nitrite and the subsequent reaction of chloramine derivatives with iodide. The resulting triiodide ion is measured spectrophotometrically at 350 nm. Raising pH of the hypochlorite solution and the reaction bath temperature for chlorination, the peak area of MEA having primary amino group decreased, that of DEA and Methyl EA having secondary amino group was approximately constant, and that of TEA and Diethyl EA having tertiary amino group increased. Therefore, pH of the hypochlorite solution was adjusted at 6.5 (phosphate buffer) and the reaction bath temperature at 65°C. The calibration curves for alkanolamines were linear within a range of (1.530) nmol. The satisfactory result for precision and recovery was obtained by analysis of the solution containing known amounts of alkanolamines. The proposed method does not require any pretreatment of samples, because it involves both the separation and the selective detection steps. Alkanolamines in the commercial shampoos were determined directly without any interference.View full abstractDownload PDF (811K) -
Kazuhiko TANAKA1981 Volume 30 Issue 6 Pages 358-362
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe ion-exclusion chromatography with a cation exchange resin (H+ form) using water as an eluent was investigated for the determination of HCO3- in biological nitrification process water. Bicarbonate ion in the effluent from the column was monitored by a conductometric detector (COND) and a flow coulometric detector (FCD) based on the electrochemical reaction of hydrogen ion from H2CO3 with p-benzoquinone at a constant applied potential (+0.45 V vs. Ag-AgI). A good separation of HCO3- from the diverse anions such as Cl-, SO42-, NO3-, PO43-, and NO2- was accomplished by elution with water alone. The calibration graph for HCO3- obtained by the COND was nonlinear, probably because of the low dissociation of H2CO3 at higher concentrations. However, the linear relationship was obtained over the range (10200) ppm of HCO3- by the FCD. Therefore, it is recommended to use the FCD in this method. The reproducibility of the peak area of chromatogram of HCO3- obtained by the FCD was satisfactory with a coefficient of variation of 1.9 % for ten determinations of 10 ppm of HCO3-. The present method was applied to the determination of HCO3- in the process water under the aerobic conditions over the pH range 510 with satisfactory results.View full abstractDownload PDF (860K) -
Hidetsuru MATSUSHITA, Takuya SHIOZAKI, Yukihiko KATO, Sumio GOTO1981 Volume 30 Issue 6 Pages 362-368
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA routine method is presented for the analysis of benzo[a]pyrene(BaP) in airborne particulates. This method consists of ultrasonic extraction, liquid-liquid partition and high performance liquid chromatography. Airborne particulates were collected on a glass fiber filter by a high volume air sampler. A part of the filter (filter area; ca. 8.6 cm2) was placed in a centrifuge tube, and 1 ml of ethanol and 3 ml of benzene were added to the filter, successively. After removing airbubbles attached to the filter by a spatura, the tube was treated by the ultrasonic agitation for 10 min at (1520)°C. This operation was repeated twice in order to completely extract BaP on the filter. After the centrifugation at 3000 rpm for 10 min, 2 ml of the BaP extracted solution was transferred to a small test tube, and 3 ml of 5% sodium hydroxide solution was added. The tube was vigorously shaken for 1 min and then centrifuged at 3000 rpm for 10 min. BaP in the benzene layer thus obtained was analyzed by a high performance liquid chromatograph attached with spectrofluorometer as a detector in the following conditions: column, Nucleosil 7C18 (4.6 mmφ×250 mm); mobile phase, acetonitrile-water (8:2, v/v); flow-rate, 1 ml/min; temperature, 45°C; excitation and emission wavelength, 370 nm and 406 nm, respectively. Dissolved oxygen in the mobile phase had been removed by nitrogen gas bubbling and sonification. Recovery of BaP and its coefficient of variation in this method were 102 % and 3.45%, respectively. The method was evaluated using the same samples in comparison with the ultrasonic extraction-one dimensional dual band TLC-spectrofluorometric method and the values were in good agreement for all results. BaP concentrations as low as 0.05 ng can be determined by the present method.View full abstractDownload PDF (1344K) -
Masahiko IKEDA, Jiro NISHIBE, Taketoshi NAKAHARA1981 Volume 30 Issue 6 Pages 368-374
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA system is described which permits the atomic absorption spectrometric determination of arsenic, lead and tellurium after formation of their volatile hydrides. The apparatus consists of an electrically heated quartz cell atomizer which has several advantages in terms of sensitivity and noise characteristics and of a newly-developed, automated hydride generation system which enables the gaseous hydrides produced by sodium borohydride to be introduced directly into the cell. To achieve the optimum performance for these elements, some fundamental parameters affecting their production and introduction have been investigated. From the results on relative stability of arsenic, lead and tellurium hydrides, for the former one, both direct transfer and collection modes can be used, whereas for the latter two the use of such a direct transfer mode as used in the present hydride generation system is undoubtedly preferred. The sensitivities for these elements appear to be strongly dependent on relative stability of their hydrides. Furthermore, a low sensitivity for tellurium could be due to a notable loss of the hydride by its reaction or dissolution with water as well as to the instability of tellurium hydride. Under the optimum conditions, the detection limits (S/N, =2) are 0.5 ng/ml, 1 ng/ml and 1 ng/ml for arsenic, lead and tellurium, respectively and the reproducibilities (RSD's) of the present method based on ten determinations of As 0.05μg/ml, Pb 0.1 μg/ml and Te 0.1 μg/ml range from 0.5 % to 1.0 %. Analytical calibration graphs obtained under the optimum conditions have linear dynamic ranges up to As 0.1 μg/ml, Pb 0.5 μg/ml and Te 0.5μg/ml. Additionally, the reagent blanks in the present system are of little or no significance.View full abstractDownload PDF (1073K) -
Takahiko MATSUEDA1981 Volume 30 Issue 6 Pages 375-379
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA simple method is proposed for the determination of anionic surfactants in water by flame photometry. The anionic surfactants such as linear alkyl benzenesulfonate (LAS), alkyl sulfate and di-(2-ethylhexyl)-sulfosuccinate are extractable as ion pairs with sodium into methyl isobutyl ketone (MIBK) from aqueous media quantitatively in the presence of sodium chloride. Therefore, the concentration of the anionic surfactants can be determined indirectly by measuring sodium in the MIBK layer by flame photometry. The effects of pH and sodium chloride concentration on the determination of anionic surfactant (LAS) were examined. The recommended procedures are as follows. Place a water sample solution containing not more than 80 μg of LAS, and 5 ml of 20 w/v % sodium chloride solution in a 120 ml graduated test tube (if necessary, adjust the pH to a value higher than 5 with sodium hydroxide solution), and then adjust the volume to 100 ml with water. Add 10 ml of MIBK, and shake the mixture for 1 min and allow to stand for 15 min. Aspirate the MIBK layer directry to flame photometer (Perkin Elmer 403) and measure the flame photometric intensity of sodium at 589 nm. A linear relationship was observed between the flame photometric intensity of sodium in the MIBK layer and the amounts of LAS in the range of (580) μg/100 ml of the aqueous phase and the coefficient of variation was 1.5% for 25μg of LAS. The presence of cationic surfactant (benzethonium chloride) and amphoteric surfactant (lauryl betain) interfered seriously. The values determined by the proposed method were always lower than those by the Methylene Blue method. The proposed method is very simple and rapid in comparison with the Methylene Blue method, and useful for the determination of trace amounts of the anionic surfactants inriver water, tap water and sewage water.View full abstractDownload PDF (804K) -
Akira MIYAZAKI, Akira KIMURA, Yoshimi UMEZAKI1981 Volume 30 Issue 6 Pages 379-384
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSDetermination of trace amounts of phosphinic and phosphonic acids is important to clarify the complex behavior of phosphorus compounds in natural water and effluent. Phosphonic acid was oxidized with iodine to phosphoric acid at pH 7. Phosphinic acid remaining unchanged in the sample was reduced to phosphorus hydride with granular zinc in 1.6 N hydrochloric acid containing 3 ml of 10 % NiCl2·6 H2O and 0.5 mg of Sn(II). Nickel accelerated the reduction and enhanced the rate of evolution of phosphorus hydride. The hydride evolved was collected (10 min) in a liquid nitrogen trap and swept into plasma after being kept the U-tube at room temperature for 20 s by passing Ar gas slightly. The P I 214.91 nm emission line intensity was measured. Total amount of phosphinic and phosphonic acids was determined from the calibration curve for phosphinic acid without the iodine pretreatment. Since the ratio of the slope of calibration curve for phosphinic acid to that for phosphonic acid was 5.18: 1, the amount of phosphonic acid was calculated as follows; P (III) =5.18 × {total amount of P(I) +P(III) measured with the calibration curve for phosphinic acid-amount of P(I) determined previously}. The limits of detection (at 3σ) were 1.5 ng P/ml for phosphinic acid and 7.9 ng P/ml for phosphonic acid. The relative standard deviations (n=10) were 3.5 % for 25 ng P(I)/ml and 4.0 % for 150 ng P(III)/ml, respectively. The recovery test for the synthesized samples gave satisfactory results.View full abstractDownload PDF (1039K) -
Masato MAMIYA, Eizen ISHII, Tetsuro MURAKAMI1981 Volume 30 Issue 6 Pages 385-389
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA combined method between the high performance liquid chromatography (HPLC) and the diffuse reflectance infrared spectrometry (DRIR) was studied through the measurement of time displaced plots of the individual spectrum of eluate from HPLC. The solution eluted from the UV detector of the HPLC was preconcentrated by a factor of five to ten in a short heated tube evaporator. The solution from the tube was then dropped and held on an arranged DRIR sample dish containing powdered alkali halide such as potassium bromide. The solvent in eluted solution on the dish was vaporized by a dryer or vaccum evapolator. We can thus measure a series of the DRIR spectra of non-volatile components remaining as thin film on the potassium bromide surface by the use of the JASCO model EDR-31 emission less DRIR spectrometer. The detection limit was in microgram order and chromatographic information was stored on a series of sample dishes. Therefore, the present method was found to be very usefull for comparison and identification of the data.View full abstractDownload PDF (961K) -
Masato AIHARA, Mitsuo KIBOKU1981 Volume 30 Issue 6 Pages 390-394
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSPotassium xanthates (potassium ο-alkyl dithiocarbonate; KRX) react with many metal ions, and so the complex formation with iron(II, III) ion and the extraction of their complexes has been studied to some extent, but those of ruthenium(III) have not been. Iron-xanthate and ruthenium-xanthate complexes can be extracted into methyl isobutyl ketone (MIBK) from weakly acidic solution to weakly alkaline solution. For quantitative extraction of iron (20μg/40 ml), KRX concentration should be above 2.0×10-2 mol dm-3 of KEtX, 1.0×10-2 mol dm-3 of KPrX, and 5.0×10-3 mol dm-3 of KBtX and KPeX, and for that of ruthenium (202μg/40ml), it should be above 2.0×10-1 mol dm-3 of KEtX and KPrX. Formation constant of ruthenium-xanthate complexes is presume to be small. A 100-fold excess of Ni(II), Co(II), Cu(II), WO42-, PO43-, CrO42-, and Cr2O72-interfered with the determination of iron, however, the interferences are eliminated by adding 5ml of 0.1 mol dm-3 ascorbic acid solution. For the determination of ruthenium, a 50-fold excess of Ag(I), Hg(II), Pb(II), Zn(II), Mn(II), Cr(III), and Pt(II), or a 100-fold excess of NO2-, S2O32-, CrO42- and Cr2O72-, respectively, interfered. The coefficient of variation after each ten runs, ranges from 0.9% to 3.2% in the determination of 10μg, 20μg, and 30μg of iron, and from 1.4 % to 4.3 % in the determination of 100μg, 200μg, and 300μg of ruthenium. The determination limit in aqueous samples is 0.02 ppm for iron and 0.2 ppm for ruthenium, when the volume ratio of aqueous phase to organic phase (MIBK) is 10:1.View full abstractDownload PDF (886K) -
Masato AIHARA, Mitsuo KIBOKU1981 Volume 30 Issue 6 Pages 394-397
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSGold(III) reacts with potassium xanthates (KRX: R=Alkyl group and benzyl radical) to form complexes, but the solvent extraction of them has not been reported. The extractability of these complexes into methyl isobutyl ketone (MIBK) was investigated and a new method for the extraction-atomic absorption spectrophotometry of gold at ppm levels has been developed. The optimum pH range for the extraction of gold(III) was 6.0 to 8.5, and was nearly the same even when the radical(R) of the xanthates was different. The minimum concentration of KRX for the quantitative extraction of gold (20 μg/40 ml) was about 4 × 10-2 mol dm-3, and below this concentration, the absorbance by the gold complex at 242.8 nm decreased. A 100-fold amount of Ag(I), Hg(II), Cd(II), Pb(II), Ni(II), Co(II), or Fe(III) interfered with the determination of gold. The interferences of diverse ions could be eliminated by adding 2 ml of 0.1 mol dm-3 EDTA solution for Ag(I) and Ni(II), by adding 2 ml of 0.01 mol dm-3 EDTA solution for Hg(II), Cd(II), and Pb(II), by adding 2 ml of 0.2 % potassium ferricyanide solution for Co(II), and by adding 2 ml of 0.2 % sodium pyrophosphate solution for Fe(III), respectively. The coefficient of variation of this method after 10 runs was (0.44.3) % in the determination of (1030) μg of gold(III). Among the KRX examined, pentyl derivative (KPeX) was found to be the most suitable reagent for this method. Gold in human organs could be detected only in 2 samples out of 36 organ samples tested by this method. No matrix effect was observed when practical sample solutions were tested by a standard addition method.View full abstractDownload PDF (768K) -
Noriko OHNO, Tadao SAKAI1981 Volume 30 Issue 6 Pages 398-402
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSTetrabromophenolphthalein ethyl ester (TBPE) forms red colored charge transfer complexes with amines, such as diphenhydramine, dibucaine and procaine in 1, 2-dichloroethane, and the complexes show reversible thermochromism with temperature changes (TBPE·H·R3N_??_TBPE·H+R3N). The decrease of absorbance with rising of temperature (1/T, T=absolute temperature) is linear and the absorbance changes against temperature changes (ΔA/Δt) are characteristic for each amine. For instance, ΔA/Δt for 2×10-6 M diphenhydramine is 7.48×10-3, ΔA/Δt for 2×10-6 M dibucaine, 6.96×10-3, and the value is constant when the concentration of amine is definite. The coefficients of variation for these values are within. 2 %. These thermochromisms were applied to fractional determinations of basic pharmaceuticals containing amines and quaternary ammonium salts. The procedure is as follows: Pipette the adequate amounts of the sample solution containing dibucaine and diphenhydramine into a 100 ml separatory funnel, and add 2 ml of TBPE solution (4×10-3 M) and 5 ml of borate-phosphate buffer solution (pH 8.0) to it. Dilute the mixture with water to 50 ml. Shake with 10 ml of 1, 2-dichloroethane for 5 min mechanically. After phase separation, transfer the organic layer into a stoppered test tube and centrifuge to remove water droplets. Measure the absorbance of the organic layer at 25°C at 555 nm (A nm) and 573 nm (B nm) against the reagent blank, then measure again at the same wavelengths (A nm and B nm) after temperature was raised to 50 °C. The difference of absorbance at 25 °C and 50 °C at 555 nm (A nm) is given by
ΔEA=ΔεI, AC1+ΔεII, AC2…(1)
and ΔEB at 573 nm (B nm) is given by
ΔEB=ΔεI, BC1+ΔεII, BC2…(2)
Where ΔεI, A and ΔεII, A are the differences of molar absorptivities of dibucaine and diphenhydramine at 555 nm (A nm), and ΔεI, B and ΔεII, B are the differences at 573 nm (B nm). C1 and C2 are the concentrations of dibucaine and diphenhydramine, respectively. As the results, C1 and C2 are calculated from equations (1) and (2). Accordingly, on this thermochromism method, two mixed amines can be simultaneously determined without any interferences.View full abstractDownload PDF (1008K) -
Masashi GOTO, Terumoto SHIROEDA, Daido ISHII1981 Volume 30 Issue 6 Pages 403-407
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA simple system was developed for the automatic and continuous determination of COD (chemical oxygen demand) in environmental waters based on amperometry of permanganate. A sample, a solution of 10 % sulfuric acid containing 10 % phosphoric acid and a solution of 0.50 mM potassium permanganate are continuously pumped with a peristaltic pump at each flow rate of ca. 50 μl/min. The sample is mixed at first with the acid solution and then with the permanganate solution in the mixing joints. The mixture is introduced into a reaction tube made of Teflon tubing (0.5 mm inner diameter, 10 m length), being placed in a boiling water bath. After reaction, the mixture goes through a thin layer electrolytic cell operated at the applied potential of 0.40 V vs. Ag/AgCl. The reduction current of permanganate present is continuously recorded. The COD value of the sample is automatically estimated from the amount of decreased current. A residence time of the mixture in the reaction tube was about 20 min. This system was successfully applied to COD measurement of river and pond waters, and to continuous monitoring of COD in sewage of laboratories.View full abstractDownload PDF (867K) -
Yuko YAMASHOJI, Takayuki MATSUSHITA, Toshiyuki SHONO1981 Volume 30 Issue 6 Pages 407-411
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSPolymeric cationic surfactant, poly (4-vinyl-N-dodecyl pyridinium bromide), was applied to the spectrophotometric determination of metal ions in the systems of MTB-lanthanum, XO-lanthanoids, CAS-beryllium and ECR-beryllium. In the XO-lanthanoids (Ce3+, Sm3+, Eu3+ and Gd3+) systems, the molar absorptivities obtained under the same conditions as that of the previous XO-lanthanum system were 1.58×105 (611 nm), 1.26×105 (613 nm), 1.06×105 (611 nm) and 1.03×105 (613 nm) cm-1 mol-1 l, respectively. Addition of this polymeric surfactant to the MTB-lanthanum system resulted in a bathochromic shift of the absorption maximum of 603 nm to 650 nm with a marked increase in absorbance. This indicates the formation of ternary complex. Beer's law was obeyed over a range of 0.8×10-6 M to 8×10-6 M for lanthanum. The molar absorptivity was 1.07×105 cm-1 mol-1 l under optimum conditions (the suitable pH range was 6.07.0, the concentration of MTB was a 5-fold molar excess over lanthanum and that of polymeric surfactant was a 2-fold molar excess over MTB). The enhancement of the absorbance and bathochromic shift of the absorption maxima for the systems of CAS- and ECR-beryllium were observed by the addition of this polymeric surfactant.View full abstractDownload PDF (678K) -
Hiroshi NISHIDA1981 Volume 30 Issue 6 Pages 412-414
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSLead (II) interfered seriously in the spectrophotometric determination of copper(II) with trithiocyanuric acid (TTCA) and nonionic surfactants; the absorbance of copper increased with an increase in the concentration of lead(II). However, in the absence of copper (II), lead(II) did not form a complex with TTCA. Therefore a mixed complex of copper (II) and lead (II) may be formed with TTCA. This reaction was applied to the determination of a small amount of copper(II). The recommended procedure is as follows: To an acidic solution containing less than 40μg of copper(II), add 0.7 ml of lead nitrate solution (1.6 mg ml-1), 2 ml of Tween 20 solution (0.1 g ml-1) and 2.0 ml of TTCA solution (4 mg ml-1). Adjust the pH 3.2 with sodium acetate solution (0.25 M) and dilute to 25.0 ml with water. Allow to stand for 60 min and measure the absorbance at 360 nm against the reagent blank. Beer's law was obeyed for (140) μg of copper. The apparent molar absorptivity was 3.6×104l mol-1 cm-1 and about four times that in the absence of lead(II). Less than 1 mg of Ca(II), Mg(II), Cd(II), Ni(II), Co(II), Mn(II), Fe(II), Zn(II), Al(III), Cr(III) and 0.02 mg of Pb(II), Pd(II) and Bi(III) did not interfere. Since the slope of the calibration curve was varied with variation of lead(II) concentration, the standard addition method was adopted for the determination of (120)μg copper in solutions containing lead; in this manner, less than 0.3 mg of lead(II) did not interfere.View full abstractDownload PDF (542K) -
Eiko NAKAMURA, Hiroshi NAMIKI1981 Volume 30 Issue 6 Pages 414-416
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSMercury standard solutions {(5500)μg/l} containing (83000) mg Fe/l of colloidal Fe(OH)3 were prepared from HgCl2 solution and colloidal Fe(OH)3 solution. These mercury solutions were stocked a glass bottle and were analyzed the mercury concentration periodically by atomic absorption method using a freshly prepared mercury standard solution in 0.1N HNO3 as the reference. At iron concentrations 800 mg/l, 80 mg/l, and 40 mg/l, mercury solutions of 5μg Hg/l were stable at least for ten months, while the 5μg/l mercury solution containing iron at a concentration of 8 mg/l decreased in the mercury concentration by 50 % during one month. The 500μg /l mercury solution containing collidal Fe(OH)3 at 3000 mg Fe/l was also stable by 100 times dilution with water. This method is not only easy in preparation but also very convenient because a standard solutions of lower concentrations can be prepared by diluting a concentrated standard solution with only water without addition of any reagents.View full abstractDownload PDF (523K) -
Toshiaki NOMURA, Mamoru OKUHARA, Kanako MURATA, Osamu HATTORI1981 Volume 30 Issue 6 Pages 417-418
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe change in oscillation frequency of a piezoelectric quartz crystal immersed in organic solvents was studied with special interest to analytical applications. The change in oscillation frequency depended upon the specific gravity and viscosity of the solvents. When the electrolyte was dissolved into the solvents, the frequency decreased with increasing amount of the electrolyte added depending upon the increase of the specific conductivity. In addition, the frequency of the crystal immersed in the organic solvent containing oxinate chelates changed depending upon the kind of complexes. From these behavior, the detector of a piezoelectric quartz crystal seems to have various applications especially as a detector for liquid chromatography.View full abstractDownload PDF (393K) -
Tsutomu FUKASAWA, Masaaki IWATSUKI, Kenji KAWANA1981 Volume 30 Issue 6 Pages T55-T60
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSHygroscopic properties of airborne particulates, weld fumes, and membrane filters, conditions for controlling their adsorbed moisture, and precise weighing were studied. A desiccator equipped with a miniature fan for agitating the atmosphere was used to control the adsorbed moisture of the samples. The humidity in the humidistat was adjusted with a sulfuric acid solution, and the temperature was controlled by dipping the lower part of the desiccator in water of a thermostat. The dried or moist materials described attained to equilibrium weights within about 12 h in an atmosphere of 20°C, 50% humidity. The moisture adsorption was similar to the BET type due to multilayer adsorption: The adsorbed moisture on the materials increased abruptly with increasing humidities over 70%, and variation of the moisture was small under lower humidities than 50%. Weld fumes were less hygroscopic than the airborne particulates. Standing these materials during more than 12 h in the atmosphere of (20±1)°C and (50±1)% humidity are recommended for their precise weighing. More than about 100 mg of the sample can be weighed within 1 % of relative precision. The membrane filters tested, and minor sample of the particulates or fume collected on a membrane filter can be weighed within 0.1 mg of precision by use of a counterpoise.View full abstractDownload PDF (1053K) -
Kenjiro HAYASHI, Yoshiaki SASAKI, Shoji TAGASHIRA, Kazuharu ITO1981 Volume 30 Issue 6 Pages T61-T64
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe color of aluminum-aluminon lake in the solution was altered by kinds of added dispersants and their concentrations. The dispersibilities of gum arabic, starch and several surfactants for the lake were examined and it was concluded that nonionic surfactant such as Triton X-100(TX-100) was most useful dispersant. From the absorption maximum of the lake (λmax)-ET value relationship in the various solvents and the increase in stability of the lake by the addition of TX-100 in water, it may be assumed that the phenyl or carboxyl groups in aluminon is linked by a hydrogen bond to the polyoxyethylene chains in the micelle surface or in the micelle mantle. The recommended procedure for the determination of aluminum is as follows: Take an aliquot of sample solution (under 40 μg of Al). Add 3 cm3 of 1 % aluminon, 1.5 cm3 of 1 mol dm-3 acetate buffer (pH=4.8) and boil the solution. Then add 1.5 cm3 of 20 % TX-100 and make the solution to 30 cm3 with water. Measure the absorbance at 537 nm against the reagent blank. The color of the solution was stable within 1 d after coloration. The molar absorptivity of complex was 2.2×104 and obeyed Beer's law between 6.5×10-7 mol dm-3 and 5.0×10-5 mol dm-3 of aluminum. The proposed method was applied to the determination of aluminum in a seaweed and the result was in good agreement with that obtained by the Pyrocatechol Violet method.View full abstractDownload PDF (597K) -
Akemi YASUI, Hideo KOIZUMI, Chuichi TSUTSUMI1981 Volume 30 Issue 6 Pages T65-T71
Published: June 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSAdding interference suppressing reagent-atomic absorption spectrophotometric method was studied on application to dry ashed food sample solutions. Calcium in the composite matrix model solutions (corn, brown rice, barley, apple, soy bean, sweet pepper, KAWANORI, spinach, NAGAKONBU, URUKA, IKA-SHIOKARA and NARAZUKE) which contained calcium, phosphate, potassium, magnesium and sodium, was determined with or without adding interference suppressing reagent by using both acetylene-air flame and acetylene-nitrous oxide flame. In AAS method using acetylene-nitrous oxide flame, interference was most overcome by measuring at solution containing more than 250 ppm of potassium, more than 500 ppm of sodium, or more than 10000 ppm of lanthanum or strontium. But, this flame is not so easy to use, and the cost is relatively high. In AAS method using acetylene-air flame, interference by phosphate was completely overcome by measuring at solution containing appropriate concentration of strontium or lanthanum according to PO4/Ca ratio. It was effective to measure at solution which contained 1000 ppm, 3000 ppm, 6000 ppm of strontium, and 10000 ppm of lanthanum about sample solutions of P/Ca 02, 1020 and 2060, respectively. Calcium in NBS SRM (Wheat Flour and Rice Flour) and corn was determined by both AAS methods. The results were agreed with the certified values. Proposed AAS method using acetylene-air flame is simple, rapid and accurate, and able to apply for most food samples except for "SHIOKARA" which contains more than 200 fold of sodium to calcium.View full abstractDownload PDF (1201K) -
Toshiyuki HOBO, Masaaki YAMADA, Shigetaka SUZUKI, Shun ARAKI, Akira SH ...1981 Volume 30 Issue 6 Pages T71-T76
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSIn order to achieve a reliable identification of amino acid enantiomers by using gas chromatography, sequential use of enantiomeric phases have been evaluated. It is based on that the elution order of D- and L-amino acid esters is reversed when the chirality of the phase is reversed. For this kind of works, the reliability of retention values is essential. Therefore, we have first measured the retention indices and separation factors of various protein and nonprotein amino acid enantiomers on N-lauroyl-L-valine-t-butylamide (phase-L) and N-lauroyl-D-valine-t-butylamide (phase-D). These phases have shown the highest separability among the phases ever reported. The columns used were whisker walled glass capillary columns. It was revealed that the retention indices on phase-L show little difference over the experimental temperature range while those on phase-D show gradual increase with the temperature rise. The separation factors on both phases decreased with the temperature increase. The reproducibility of the retention indices were good enough for the peak identification. It should be noted that there are differences between the retention indices on the two phases, which should be elucidated later. The determination of the optical purities of the phases and identification of the moieties of an antibiotic were done successfully for the application experiments. For the identification, it was also useful to check the separation factors.View full abstractDownload PDF (1037K) -
Tatsuro TARUI, Hiroshi TOKAIRIN1981 Volume 30 Issue 6 Pages T76-T79
Published: June 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe determination of mercury in crude oil at concentrations above 5 ng/g level was performed by cold vapor atomic absorption spectrometry after decomposition by sulfuric and nitric acid in a closed system. It was found that carbonization of crude oil was accelerated and the decomposition by nitric acid could be carried out much easier if the sample was sufficiently mixed up with sulfuric acid. The digestion by nitric acid was first performed at (90100)°C for about 2 h. When the elevation of the decomposed gas ceased, the temperature was gradually elevated until the sulfuric acid fumed out and the distillates were collected in a pressure equalizing funnel. By repeating the addition of nitric acid (first 20 ml and then 10 ml, 10 ml, 5 ml and 5 ml, successively) and heating of the solution, (23) g of crude oil was completely decomposed within 7 h. Mercury cyclohexanebutyrate was used as a standard of organic mercury compounds. The overall recovery was 101 % when 200 ng of mercury was added to 2 g of light gas oil. Mercury contents of ten different crude oils were determined by the present method.View full abstractDownload PDF (622K)
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