A novel reversed-phase partition liquid chromatography-photometric detection system for the determination of trace amounts of vanadium is described. A strongly colored vanadium(V)-2-(8-quinolylazo)-5-N, N-diethylaminophenolato chelate is separated on a μBaondapak-CN column using an aqueous acetonitrile mobile phase and is detected at 540 nm(0.02 absorbance unit full-scale). Because the other common cations give no resolved peaks on the chromatogram under the conditions, the determination of vanadium at 5×10^-8 to 1×10^-6 mol dm^-3 level is free from their interferences in case of the total concentration of such cations less than 5×10^-5 mol dm^-3.

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An indirect method based on the decrease in stripping peak height of mercury (II) caused by sulfide ions is proposed for the determination of hydrogen sulfide at the low ppb level in the atmosphere. Atmospheric hydrogen sulfide is quantitatively absorbed in 20 ml of 0.4 M sodium hydroxide solution at a bubbling rate of 0.5 l min^-1. To the solution, 0.2 ml of 6.3×10^-4 M mercury (II) solution is added, and the mercury is electrodeposited onto a platinum microelectrode at -0.25 V vs. the SCE. for 3 min. After 30 s, the electrode potential is scanned at a rate of +40 mV s^-1, an anodic stripping curve being recorded. The mercury (II) peak height decreases linearly with increasing hydrogen sulfide in the range of 0.003 μg to 0.048μg. By this simple and rapid method, 0.2 ppb to 3.5 ppb (v/v) of hydrogen sulfide in 10 l air samples is determined with a coefficient of variation of about 10%.

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Collection of cobalt (II), nickel (II), copper (II), zinc(II), cadmium (II), mercury (II), and lead (II) with xanthated Sephadex (X-Sephadex) was invstigated by the batch system involving various salt solutions. Each metals were collected with X-Sephadex completely from 1 M solution of sodium nitrate, sodium chloride, and sodium bromide. Although mercury and copper were collected completely from 1×10^-1 M and 1×10^-2 M EDTA solution, respectively, the other metals were seriously affected by the presence of EDTA and the collection yields were lowered even by 1×10^-5 M EDTA. Based on these findings, the separation of mercury and lead was carried out as follows. From 500 ml sample solution containing 5.00×10^-4 mmol each of these metals, mercury was collected by stirring with 0.1 g of the X-Sephadex at pH 1.5. The X-Sephadex collecting mercury was filtered and then lead was collected with another fresh X-Sephadex from the filtrate after adjusting to pH 5.2. The respective X-Sephadex collecting mercury and lead was washed with water and the metals were dissolved with 10 ml of conc. hydrochloric acid for determination by atomic absorption. The separation of mercury or copper from other metals such as cobalt, nickel, cadmium, and lead was also successful by the similar procedure. The separation of copper and cadmium by the column system was carried out as follows. Both 5.00×10 ^-4mmol of copper and cadmium were collected together by passing 500 ml sample solution at pH 6.36.5 through a column packed with 0.2 g of X-Sephadex. Cadmium was eluted with 1×10^-2 M EDTA solution and then copper was dissolved with a hot mixture of 30 % hydrogen peroxide (0.5 ml) and 18 N sulfuric acid (2 ml). Similarily, quantitative separation of copper from lead and mercury from cadmium was also achieved.

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A method for the determination of hydrogen chloride and sulfur dioxide in the atmosphere by using an alkali filter and ion chromatography was studied. The gases were collected on an alkali filter (Whatman 41 cellulose filter impregnated with 2 % Na₂CO₃ and 2 % glycerol). The collection efficiencies of the gases in the field measurement were > 99.0 % for hydrogen chloride and 96.9 % for sulfur dioxide at a flow rate of 20 l/min. The alkali filter was extracted with the eluent solution (0.0024 M Na₂CO₃/0.003 M NaHCO₃), and Cl^-, SO₃^2-, and SO₄^2- were determined simultaneously by ion chromatography. The chloride represented hydrogen chloride and the combined sulfite and sulfate represented sulfur dioxide in the air sample. The oxidation of SO₃^2- to SO₄^2- in the solution was a problem in the spectrophotometric determination of SO₃^2- by using p-rosaniline, but, the problem was avoided in the ion chromatographic analysis. The proposed method. enabled the facile determination of atmospheric hydrogen chloride and sulfur dioxide at sub ppb levels. The analytical precision of the method was within 4 % for both hydrogen chloride and sulfur dioxide.

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Porous maleic anhydride-divinylbenzene copolymer beads (MA) were applied for a subtractor in reaction gas chromatography. The polymers were prepared by suspension copolymerization of maleic anhydride with divinylbenzene in a glycerol solution of 0.2 % hydroxyethyl cellulose containing sodium chloride. A mixture of toluene and dioxane (1 : 1) was used as diluent in the polymerization. Three polymers which had different capacities were prepared, and their capabilities as subtractors were tested. Among the polymers, MA-II was the most effective as the subtractor. The tested column (1 m × 3 mm i. d., glass column) was composed of a part of subtractor precolumn (MA-II, 10 cm) and a part of analytical column (90 cm), and the percent capture of amines was determined by comparing their peak areas with and without the precolumn. It is well known that monomeric acid anhydrides react in general with alcohols and amines, but alcohols were not entirely subtracted on the proposed column. Primary and secondary amines except t-butylamine, t-amylamine, and diisopropylamine which have bulky alkyl groups were completely subtracted in addition to aromatic amines. Tertiary amines, hydrocarbons, ethers, ketones, aldehydes, alkylhalides, mercaptanes, esters, and epoxides were not subtracted. The subtractor column could be used more than 100 injections of 0.1 μl of butylamine without any loss of capabilities.

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A simple and rapid method was established for the separation and determination of octahedral geometric isomers of cobalt (III), chromium (III), and rhodium (III) chelates of benzoylacetone (BA) and trifluoroacetylacetone (TFA) by thin-layer chromatography and densitometry. The separation of cis and trans isomers of Co (BA)₃, Cr (BA)₃, Rh (BA)₃, and BA was achieved successfully on 1) alumina (basic), 2) Silica gel, and 3) dimethylsilyl Silica gel plates by using toluene and benzene for 1), benzene and dichloromethane for 2), and toluene, benzene, and carbon tetrachloride for 3). The separation of cis and trans isomers of Co (TFA)₃, Cr (TFA)₃ and Rh (TFA)₃ was performed on 1) alumina (basic), 2) Silica gel, and 3) dimethylsilyl Silica gel plates by using hexane and toluene for 1), benzene for 2), and toluene for 3). The separation of geometric isomers of the three TFA chelates and TFA was performed also with a mixed solvent such as hexane-dichloromethane (10 : 2.5) for 1), and hexanebenzene (10 : 10) and toluene-dichloromethane (10 : 1) for 2). The chelates on a TLC plate was determined with Shimadzu High-speed TLC Zig-zag Scanner (model CS-920). The detection limits of the isomers were in the concentration range of (28) × 10^-6 mol/l for 1 μl of sample. All the calibration curves for the twelve isomers were linear in the concentration range of (10^-510^-3) mol/l. The coefficient of variation for the determination of each isomer in BA chelates and TFA chelates was (0.262.4) % for cis isomers and (0.210.63) % for trans isomers. Good agreement was observed between the results obtained by the proposed method and the HPLC.

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A simple and rapid method for the direct determination of lead in NBS bovine liver SRM 1577 by Zeeman atomic absorption spectrometry using an inner graphite miniature-cup in conjunction with an electrothermal graphite furnace of a crucible type was developed. In order to introduce a small amount of powder samples into the graphite furnace of the crucible type, five kinds of the miniature-cups were made of an experimental basis, and examinations were carried out of these miniature-cups for the determination of lead in solid and liquid samples. The miniature-cup which has an inner diameter 3.0 mm, outer diameter 3.8 mm, height 3.0 mm, and depth 2.5 mm was the most useful. The optimal thermal programs obtained were as follows, precharring at 220°C for 60 s, charring at 600°C for 120 s, atomization at 2200°C for 7.5s, and auto cleaned at 2300°C for 3 s. The absolute sensitivity for lead was 1.8×10^-11 g and the detection limit was 5.1×10^-12 g. Analytical line used was 283.3 nm. The results for the determination of lead in the NBS bovine liver by the calibration method using the lead aqueous standard solution (0.1 N-HCl soln.) were 0.38 μg/g, and 0.32 μg/g which were good agreements with the certificated value {(0.34±0.8)μg/g}, and their coefficients of variation for 15 and 9 measurements were 7.3 % and 6.3 % respectively. This direct determination method was applied to the NBS oyster tissue and the NBS tomato leaves, and good linear relationships between absorbances of lead and sample weights have been obtained.

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A simple and rapid method is described for the direct determination of cadmium in the NBS bovine liver, SRM 1577 by Zeeman atomic absorption spectrometry using the graphite miniature-cup in conjunction with an electrothermal furnace of a crucible type.As cadmium is volatile element, the organic matrix was not completely decomposed at a fixed temperature.The residual matrix interfered with the linearity of calibration and the precision. Inorder to decompose the organic matrixes, a few kinds of acids were examined.An addition of 5 μl of 4 N-H₂SO₄ before the start ofthe thermal program showed the remarkable improvements in the linearity of calibration and the precision. The optimal thermal programs obtained were as follows: dried at 110 °C for 60 s, charred at 240 °C for 120 s, atomized at 2100 °C for 5 s, auto cleanedat 2250°C for 3 s. The cadmium calibration curves showed a good linearity of 00.14 ng. The absolute sensitivity i. e. cadmium weight which shows 0.0044 of absorbance, was 0.003 ng. The result of determination of cadmium in the NBS bovine liver by means of the standard addition method was 0.25 μg/g which was a good agreement with the certificated value { (0.27 ±0.04) μg/g}. The coefficient of variation for 14 measurements was 9.6 %.

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Solvent extraction and spectrophotometric determination of phosphorus, arsenic (V), and arsenic (III) with molybdate and ethyl violet have been studied. Molybdophosphate and molybdoarsenate were extracted into a mixed cyclohexane-4-methyl-pentane-2-one solvent (1 : 3 v/v). The absorbance of the organic phase at 602 nm was measured and each calibration curve was found to be linear in the range 01 μg of phosphorus and 02 μg of arsenic (V), respectively. The molar absorptivity of phosphate is almost equal to that of arsenate; the value is 2.8× 10⁵l mol^-1 cm^-1 (1) In the presence of sodium thiosulfate, only phosphorus existing as orthophosphate was extracted into the organic phase. (2) In the absence of oxidizing or reducing agents, phosphorus existing as orthophosphate and arsenic (V) were extracted. (3) In the presence of potassium dichromate, phosphorus existing as orthophospate and arsenic existing as arsenic (III) and (V) were extracted. From the absorbance of the organic layer obtained by the procedure (1), phosphorus was determined. From the difference in the absorbance between the two organic layers obtained by the procedure (2) and (1), and by the procedure (3) and (2), arsenic (V) and arsenic (III) were determined, respectively. River and hot spring waters up to 10 ml were transferred into stoppered test tubes and acidified with sulfuric acid, and heated in a water bath (above 90°C) for 40 min, and subsequently these were analyzed according to the procedures (1), (2), and (3). Phosphorus and arsenic in river and hot spring waters at the several 10 ppb amounts were determined by the proposed method.

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A spectrophotometric method is described for the determination of palladium (II) with Sulfochlorophenol S (abbreviated as SCPS). SCPS reacts with palladium in acidic medium to form a blue colored complex. The maximum absorption of the complex is at 643 nm (against the reagent blank). Recommended procedure is as follows: Into a 25 cm³ volumetric flask transfer a sample solution containing less than 64 μg of palladium. Add 10 cm³ of 2× 10^-4 mol dm^-3 SCPS solution, 1 cm³ of 0.25 mol dm^-3 perchloric acid, and 1 cm³ of 2.5 mol dm^-3 sodium perchlorate solution; dilute to about 20 cm³ with distilled water. Support the flask in boiling water for five min. Cool to room temperature, dilute to the mark with water. Measure the absorbance at 643 nm against the reagent blank prepared with the same method to do the sample. Beer's law was applied in the range up to 64 μg of palladium. The apparent molar absorptivity was 4.2 × 10⁴ dm³ mol^-1 cm^-1, and the Sandell's sensitivity of the reaction was 0.002₅ μg cm^-2. Chloride, nitrate, and sulfate did not interfere at 3000-fold ratio to palladium. Fluoride and tartrate (1000-fold to palladium), platinum (IV) (200-fold) did not interfere with the determination.

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Ammonia reacts with phenol, sodium nitroprusside, sodium hypochlorite, and sodium hydroxide (condition A) producing a blue colored indophenol (630nm), but aniline is transferred to the same indophenol blue with phenol, sodium hypochlorite, and sodium hydroxide (condition B). p-Aminophenol is trasferred with phenol and sodium hydroxide (condition C). The relative reaction rates of ammonia, aniline, and p-aminophenol were 0.725, 0.308, and 1.00, respectively. These three indophenol blues had a same absorption spectrum and no interference with each other. Mixed sample containing three substances whose each concentration was 10^-8mol/ml could be determinated separately by selection of the coloring condition A, B, or C within 3 % deviation. Other amino compounds were classified into the three coloring conditions as follows. Sulfanilic acid, dimethyl aniline, mono methyl amine, and o-, m-and p-phenylenediamine belonged to the condition A. Methyl aniline, p-amino benzoic acid and o- and m-toluidine belonged to the condition B. Hydroxylamine hydrogenchloride, N, N'-dimethyl-p-phenylenediamine ando-and p-aminophenol belonged to the condition C.

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A rapid and sensitive method for the determination of beryllium in geological samples by atomic absorption spectrometry is presented. The sample {(0.10.5)g, containing less than 80 mg of aluminum} was decomposed with HClO₄, HNO₃, and HF, then evaporated to dryness. The evaporation was repeated with HClO₄ and H₃BO₃ solution, then dissolved in diluted HCl. Aluminium solution, EDTA solution, and acetylaceton solution were added, and the pH was adjusted to 5.06.5 by adding NaOH solution, then the solution was extracted with MIBK. Beryllium in MIBK layer was determined by nitrous oxide-acetylene flame. If the content of beryllium is less than 0.05μg, the MIBK layer was back-extracted with diluted HCl, and the beryllium was determined by carbon tube atomizer. If the sample containes refractory minerals, the sample was fused with a mixture of Na₂CO₃ and H₃BO₃, and the melt was dissolved in diluted HCl, then beryllium was determined after MIBK extraction. The limit of detection is 0.1 ppm by nitrous oxide-acetylene flame and 0.001 ppm by carbon tube atomizer. The relative standard deviation in the determination of 0.006 μg to 5.0 μg of beryllium is 2 % to 17 %. The method is satisfactorily applied to the variety of geological reference samples.

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The proposed gravimetric sample reduction with a kitchen mixer was fast, simple, and reliable. A homogeneous and representative aliquot was easily obtainedat once with a reduction factor of one hundred or more. The known weight of chopped and frozen sample was taken in a plastic mixer and a roughly equal amounts of water was added and weighed. From the mixed suspension, a minute amounts of aliquotwas taken by weight into a sealed Teflon vessel for the decomposition with nitric and perchloric acids at elevated temperature. The sample solution thus obtained was diluted by weight with water and served for flame atomic absorption and emission spectrometric measurements of inorganic constituents in vegetables using one-drop method. The standard solutions were also prepared gravimetrically.

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A system has been developed for the determination of nitrite and nitrate ions by flow injection analysis. The flow lines were made from polytetrafluoroethylene (PTFE) tubing. For the nitrite determination a 650 μl of sample is injected into a stream of 0.04 % (w/v) p-aminoacetophenone (p-AAP) solution in 47 mM hydrochloric acid, and flows down a mixing coil (1 mmφ×1 m) in a thermostated bath at 45°C. The mixture meets a stream of 0.11 % (w/v) m-phenylene-diamine dihydrochloride (m-PD) solution in 1.2 mM hydrochloric acid. After the mixing coil (1 mmφ× 1 m, 45°C), the absorbance at 456 nm is measured by a spectrophotometer with a 10-mm flow-through cell (8 μl) against water as reference. For the nitrate determination a 650 μl of sample is injected into 1.2 mM EDTA carrier solution (pH 9.8) and passed through a copperized cadmium column {3 mmφ×70 mm, particle size: (0.52) mm} to convert quantitatively nitrate to nitrite. Then, the carrier solution is merged into the stream of a mixed reagent solution of 0.02 % (w/v)p-AAP and 0.055 % (w/v) m-PD in 24 mM hydrochloric acid. After the mixing coil (1 mmφ× 1 m, 45°C), the absorbance is measured at 456 nm. Sampling rate was 30 samples per hour. The relative standard deviations (n= 10) were 0.97 % and 0.89 % for 10 μg/l and 30 μg/l of nitrite-nitrogen, respectively, and 0.95 % and 0.66 % for 0.1 mg/l and 0.3 mg/l of nitrate-nitrogen, respectively. A detection limit was 0.4 μg/l and 2 μg/l for nitrite- and nitrate-nitrogen, respectively.

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Wet chemical analysis as a standard analytical method and fluorescent X-ray spectrometry as a rapidanalytical method were studied in order to establish the determination procedure for chlorine in slags. The results obtained are summarized as follows. (1) Mercury thiocyanate-spectrophotometry can be applied as a wet chemical method. After slag samples have been fused with the fusing agent involving sodium carbonate and boric acid, the melt is extracted with 6 N nitric acid and iron (III) sulfate-ammonium solution and mercury (II) thiocyanate-alcohol solution are added to the solution. The concentration of chlorine is obtained by measuring the absorbance (460 nm) of the iron (III) thiocyanate color in the solution. The analytical procedure can be applied for chlorine of an amount of more than 1 % and it is also possibly applied for chlorine of an amount of less than 1 % if a larger amount of the sample is taken and the ratio of the reagents to the sample is changed. (2) In fluorescent X-ray spectrometry, glass beads are prepared by fusing slag samples with lithium borate. Using the glass beads, chlorine is determined from the X-ray intensity at Cl K_α. Calibration curve has a good linearity in the chlorine concentration range of 0.4 % to 10 % and analytical values were reproducible. The accuracy (σ_d) is 0.49 % for six kinds of samples containing 6.4 % to 11.0 % (mean : 9.4 %) of chlorine. (3) The consuming time for the analysis of one sample is about 30 min by mercury thiocyanate-spectro-photometry and is about 10 min by fluorescent X-ray spectrometry, respectively.

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The ion-exclusion chromatography (IEC) for the simultaneous determination of NO₃^-, NO₂^-, and NH₄⁺ in biological nitrification-denitrification process water was investigated. This method consists of the combination of the IEC on a cation exchange resin in the H⁺ -form with UV-detection for determining NO₃^-and NO₂^- and the IEC on an anion exchange resin in the OH^--form with coulometry-detection for determinig NH₄⁺. These IEC systems are coupled with a“delay coil tube” (1 mm i. d. × 10 m long) to separate NH₄⁺ peak from a “ghost peak” of cations such as Na⁺, K⁺, Mg²⁺, and Ca₂⁺ caused by the imcomplete cation exchange reaction in the H⁺-form cation exchange resin column. The liquid chromatograph equiped with one delively pump (1 ml/min), dual sample injector (0.1 ml each), H⁺-cation exchange resin column (9 mm i. d. × 110 mm long), OH^--form anion exchange resin column (9 mm i. d. × 550 mm long), UV detector (210 nm), and flow coulometry detector (OH^- detection) was used. The same sample solution is simultaneously injected onto each column with each sample loop, and chromatographed by the ion-exclusion. Only one kind of eluent (10 % methanol-water) was used for the separation of NO₃^-, NO₂^-, and NH₄⁺. The simultaneous determination of NO₃^-, NO₂^-, and NH₄⁺ in the actual samples was accomplished within 30 min with satisfactory results.

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Solvent extractions of cadmium(II) in aqueous sodium thiocyanate solution and 1 mol dm^-3 Na(SCN, C10₄) constant ionic media have been studied at 298 K. The extraction with methylisobutylketone(4-methy1-2-pentanone) was poor but that with trioctylphosphine oxide in hexane was effective if the concentration was above 1×10^-2 mol dm^-3. By a chelate extraction method, the stability constants of the thiocyanate complexes were determined and the extraction equilibria with these solvating type extractants were analyzed by using these constants. From a comparison of the results with those of zinc(II), it was concluded that though cadmium(II) complexes are more stable than those of zinc(II), their extractability is much inferior to that of the latter.

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The effect of pH on the collection of mercury(II) and methylmercury was investigated with nine commercially available carbonaceous materials. Specific surface area and C, H, O, N, and S in these materials were determined. Activated carbon (powder, granular, or felt) was the best adsorbent for mercury. Satisfactory recoveries were also obtained with carbon black from solutions of pH 1 to 14. In spite of the small specific surface area of anthracite, it gave fair recoveries of mercury.

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Cobalt(II) is extracted into chloroform as the ternary complex consisting of cobalt(II), zincon and zephiramine cation. By the addition of pyridine, the quaternary complex of cobalt is extracted, of which molar absorptivity is about four times that of the ternary complex. The difference of absorbances of extracts of the quaternary and ternary complexes is proportional to the concentration of cobalt. Copper(II), nickel(II) and zinc(II) at 5, 3 and 2 times the amount of cobalt, respectively, do not interfere with the determination. Iron(III) and manganese(II) decompose zincon, and interfere seriously.

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A flotation method which utilizes a zirconium hydroxide-sodium oleate-air system at pH 9.1±0.1 is described for the separation of sub-microgram levels of antimony(III), bismuth(III) and tin(IV) in water. The time required for the preconcentration was about 20 min per sample after 20 min of stirring.

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