Spectrophotometric Determination of Anionic Surfactants in River Water with Cationic AZO Dye by Solvent Extraction- Flow Injection Analysis

Anionic surfactants in water were determined by a spectrophotometric flow injection technique coupled with solvent extraction. The ion associate which formed between an anionic surfactant and an cationic azo dye was extracted into an organic solvent and the absorbance was measured. The carrier was distilled water, and the reagent solution contained an cationic azo dye and sodium sulfate, the pH of which being adjusted to 5 with acetate buffer. A phase separator with a poly(tetrafluoroethylene) porous membrane (0.8μm pore size) was used to separate the organic phase. Six derivatives of cationic azo dyes and several extracting solvents were examined; a pair of 1-methyl-4-(4-diethylaminophenylazo)- pyridinium cation and chloroform turned out best. The sampling rate was 30 samples per hour. Calibration graphs were linear up to 2×10(-6)M or 3×10(-5)M of anionic surfactant when injection volume was 300 or 100μl, respectively. The relative standard deviation(n=10) was 1.5% for 300μl of 1×10(-6)M sodium dodecylsulfate. The detection limit was as little as 1×10(-8)M of anionic surfactant. Anionic surfactants in river water were determined satisfactorily

Fluorometric determination of ammonia in river water by flow injection analysis

Flow injection analysis(FIA) was examined for the fluorometric determination of ammonia in river water. Ammonia reacted with ο-phthalaldehyde(OPA) in the presence of 2-mercaptoethanol(ME) to form a fluorescent substance at pH 9.5. The reagent solution containing 10(-2) M OPA and 10(-3) M ME and the carrier fluid(distilled water) were propelled by a double plunger pump at a rate of 1.2 ml/min. The 40μl sample solution, injected into the carrier stream, was mixed with the reagent solution in a Teflon tubing (3 m, 0.5 mm i.d.) and led to a flow cell(18 μl). Fluorescence excited at λ(ex)=350 nm was measured at λ(em)=486 nm. Ions present commonly in river waters did not interfere with the determination of ammonia. An anion exchange column installed just behind a sample injection valve in the flow system was effective in eliminating interferences with amino acids. Using the proposed FIA system, trace amounts of ammonia(3150 ppb as nitrogen) in river water were determined in the rate of 40 samples per h

Liquid-liquid distribution behavior of quaternary ammonium salts

1価陰イオンを対イオンとする第四級アンモニウム塩,テトラフェニルアルソニウム塩,テトラフェニルホスホニウム塩の抽出挙動考察のために,炭素数及び形状の異なる16種の陽イオンを用いて水-クロロホルム系での抽出定数を求めた.得られた抽出定数から次の知見を得た.(1) 1価無機陰イオンの抽出性は結晶イオン半径の大きいものほど良く,過塩素酸イオン>チオシアン酸イオン>ヨウ化物イオン>四フッ化ホウ素イオン>臭化物イオン>硝酸イオン>塩化物イオン>亜硝酸イオン>水酸イオン>フッ化物イオンの順となった. (2) アルキル鎖のメチルン基一つ当たりの抽出定数への寄与分は0.59(log単位)であり,フェニル基,ナフチル基の寄与分は2.90, 4.43であった. (3) 炭素数の同じ陽イオンの抽出性は, R-N(CH(3))(3)+>R'(4)N(+)>(C(6)H(5))(4)P(+)≈(C(6)H(5))(4)As+の順となった.これらの知見を基にイオン会合体の抽出定数の推定についても考察し,計算値と実測値との良い一致をみた.The ion association extraction of quaternary ammonium ions with univalent anions was carried out. The extraction constants (log K(ex)) for these ion-as-sociates between aqueous and chloroform phases were determined. The linear relationship was obtained between log K(ex) and the number of carbon atoms in quaternary ammonium ion, and the contribution of a methylene group to the extraction constant, π(CH(2)), was on the average 0.59. The order of the extractability of inorganic anions was F(-)R'(4)N(+)>(C(6)H(5))(4)P(+)≈(C(6)H(5))(4)(-)As(+), and the differences in log K(ex) between the respective cations in this order averaged 1.2 and 1.1 in turn. The π values for C(6)H(5)- and C(10)H(7)(-) groups were 2.90 and 4.43, respectively. By using these empirical parameters, the extraction constants for several ion associates were estimated, and the extraction constants calculated were in good agreement with those obtained experimentally in this work and those reported by other workers

Spectrophotometric determination of hydrogen peroxide by FIA with Bindschedler's Green leuco base as color reagent

ビンドシェドラーズグリーンロイコ塩基(LBG)を色原体とし,Fe(II)を触媒としたFIA系による過酸化水素の定量法について検討した.弱酸性溶液中,Fe(II)が存在するとLBGは過酸化水素によって725nmに吸収極大を持つ緑色のビンドシェドラーズグリーン(BG(+))に酸化され,この波長での吸光度の増加を利用して過酸化水素を定量した.pH及び共存させる塩酸ヒドロキシルアミンの濃度を調節することにより,過酸化水素が0~1ppmの範囲で検量線は直線性を示す.過酸化水素0.58ppmでの10回繰り返し測定の相対標準偏差は0.4%で,検出限界は5ppb(S/N=2)であった.1時間当たりの分析速度は30検体であった.市販の各種水あめ中のグルコース(3~96%)を,グルコースオキシターゼで反応させた後,FIAで測定した.A FIA method for the determination of hydrogen peroxide with a Bindschedler's Green leuco base (LBG) as color reagent and iron(II) as catalyst is described. LBG was oxidized by hydrogen peroxide to Bindschedler's Green (BG(+)) which showed a maximum absorbance at 725 nm. The increase in the absorbance at 725 nm was measured for the determination of hydrogen peroxide. The reagent solution (1) consisted of 10 mM hydrochloric acid containing 1 mM LBG, and the reagent solution (2) consisted of 0.1 M acetate buffer (pH 4.6) containing 50 mM ammonium iron(II) sulfate and 0.65 M hydroxylamine hydrochloride. Reagent solutions (1) and (2), and a carrier solution (deionized water) were propelled by two double plunger pumps (flow rate: 0.8 ml/min), and a sample solution (50 μl) was injected into the carrier stream. After mixing the reagent solution (1) and (2) in the preheating coil, the mixture stream was mixed with the carrier stream in the reaction coil (37℃). The linear relationship between the peak height and the concentration of hydrogen peroxide was obtained in the range of 0 to 1 ppm. The relative standard deviation of 0.58 ppm hydrogen peroxide was 0.4% (n=10). The detection limit was 5 ppb (S/N=2). The sampling rate was 30 samples per hour. The glucose in the range of 0 to 10 ppm was determined by the FIA method after the reaction with glucose oxidase

Spectrophotometric determination of nitrate ion using nitrosation/FIA

N, N-Bis (2-hydroxypropyl) aniline (BHPA) reacts with nitrite ion in an acidic medium to form a red product, which has the maximum absorption at 500 nm. On the basis of this color reaction, FIA of nitrate was established. Nitrate ion could be reduced to nitrite ion by passing through the reduction column(2 mm×30 cm) packed with copperized cadmium {Cu(Cd) : particle size, about 0.5 mm}, which was installed just behind the sample injection valve. The carrier solution(10(-3) M EDTA, pH 8) and the reagent solution (8×10(-4) M BHPA, 0.35 M HCl, 0.15 M H(3)PO(4)) were propelled at the flow rate of 0.7 ml/min by using a double-plunger pump. The sample(120 μl) was injected into the carrier stream by using a 6-way injection valve. The reaction coil(0.5 mm×2 m) was kept in a thermostatically controlled water bath(80℃). The cooling coil(0.5 mm×50 cm), which was installed just behind the reaction coil, was kept in a water bath (tap water temperature). A calibration curve was linear up to 2×10(-4) M nitrate. The detection limit corresponding to S/N=2 was 10(-6) M nitrate, and the relative standard deviation (10 injections) was 0.4%, and the sampling rate was 40 samples per hour. Nitrate in river water at concentrations of 10(-5) M level was determined

Solvent extraction-spectrophotometric determination of copper with 2-nitroso-5-dimethylaminophenol and zephiramine

2-Nitroso-5-dimethylaminophenol (nitroso-DMAP) reacts with copper(II) ion to form a 1:2 complex in an aqueous solution. In the presence of zephiramine (tetradecyldimethylbenzylammonium chloride), a 1:3 complex is formed and can be extracted into chloroform. The excess of nitroso-DMAP co-extracted with complex anion into organic phase can be removed by adding an adequate amount of chloride ion at about pH 12. Maximum absorption wavelength of the copper complex in the organic phase is 468 nm, at which the molar absorptivity was found to be 3.6×10(4) l mol(-1) cm(-1). This method was applied to determine micro amounts of copper in iron and steel samples and aluminium alloys. The procedure is as follows. An adequate amount of the sample was dissolved in aqua regia. The resulting solution was evaporated nearly to dryness. The residue was re-dissolved in distilled water to give an adequate volume. Five milliliters of the sample solution were taken into a stoppered test tube. Ascorbic acid and potassium chloride solutions were then added. Dichlorocopper(I) ion was extracted with chloroform solution of zephiramine. The organic phase was shaken with an aqueous solution containing hydrogen peroxide, nitroso-DMAP, potassium chloride, and potassium hydroxide to form the copper complex of nitroso-DMAP and to remove the excess of reagent in the organic phase. The absorbance at 468 nm was measured against the reagent blank

Continuous flow method for the determination of phosphorus using the fluorescence quenching of Rhodamine 6 G with molybdophosphate

Continuous flow method was examined for the determination of phosphorus. The molybdophosphate formed between orthophosphate and molybdate in hydrochloric acid medium diminished the fluorescence of Rhodamine 6 G. Carrier solution (distilled water) and reagent solution were propelled by double plunger pump P(1) and P(2) (flow rate : 0.98 ml/min), and sample solution(160μl) was injected into the carrier stream. The two streams were mixed in 20 cm long Teflon tubing (1 mm i.d.), and the mixture was flowed through a flow cell(18μl), at which the fluoresence of Rhodamine 6 G was detected(λ(ex) =350 nm, λ(em)=580 nm). The reagent solution consists of 0.035 M molybdenum and 1×10(-5) M Rhodamine 6 G in 0.8 M hydrochloric acid. Co-existing ions generally existing in river and sea waters did not interfere the determination of phosphorus. The calibration curve was linear from 0 to 45 ppb of phosphorus. The method was applied to sea water. The sampling rate was 20 samples per hour

Spectrophotometric determination of boron by flow injection analysis

H-レゾルシノール{1-(2,4-ジヒドロキシ-1-フェニルアゾ)-8-ヒドロキシナフタレン-3,6-ジスルホン酸}とホウ酸との反応を利用したホウ素の吸光光度フローインジェクション分析について検討した.ダブルプランジャー型ポンプを用い,一方にキャリヤー液(イオン交換水)を流し,もう一方に反応試薬溶液(H-レゾルシノールとEDTAを含むpH5.5の酢酸アンモニウム緩衝液)を流し,キャリヤー液流中に試料水を注入した.キャリヤー液と反応試薬液は反応コイル中で混合した.錯体の生成を促進するために,反応コイルを恒温槽中(100℃)で加熱する.その後混合液はフローセル(36μl)に導かれ,ホウ素錯体の吸光度を測定した(波長510nm).ホウ酸と反応する試薬についてはH酸(1-アミノ-8-ヒドロキシナフタレン-3,6-ジスルホン酸)誘導体14種類について検討した結果,温レゾルシノールを用いることにした.河川水,海水中に普通存在する程度の金属イオン及び無機陰イオンは定量を妨害しない.0.1M程度のナトリウムイオン,カリウムイオンは負の誤差を与えるが,海水は20倍に希釈して測定するのでこれらイオンの妨害は問題とはならなかった.検量線は0～夏PP田の範囲で直線性を示し,検出限界は5ppb(S/N=2)であった.又ホウ素108ppbでの10回繰り返し実験の相対標準偏差は0.53%であった.毎分0.6mlで送液し試料注入量320μl,反応コイル0.5mm i.d.×16mとしたときの分析速度は1時間当たり約30試料である.Spectrophotometric determination of boron existing as boric acid in water was examined with H-resorcinol {1-(2, 4-dihydroxy-1-phenylazo)-8-hydroxynaphthalene-3, 6-disulfonic acid} by flow injection analysis. Carrier solution (deionized water) and reagent solution were propelled by double plunger pump (flow rate : 0.6 ml/min), and sample solution (320 μl) was injected into a carrier stream. The reagent solution was prepared by dissolving 0.096 g of H-resorcinol in 1 1 of ammonium acetate buffer solution (50 g/l, pH 5.5) containing 3.72 g of EDTA. The two streams were mixed in 16 m long Teflon tubing (0.5 mm i.d.), and the mixture was flowed through a flow cell (36 μl; 1.5 mm i.d.×20 mm), at which the absorbance of boron-H-resorcinol complex was detected (λ=510 nm). The linear relationship between the peak height and concentration of boron was obtained in the range of 0 to 1 ppm. The detection limit was 5 ppb (S/N=2). The sampling rate was 30 samples per hour. Generally ions co-existing in river and sea waters did not interfere with the determination of boron by adding EDTA solution

Determination of cobalt by ion-pair liquid chromatography with 2-nitroso-1-naphthol-4-sulfonic acid

Cobalt was spectrophotometrically determined as an anionic metal complex of 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-NW acid) on a reversed-phase high-performance liquid chromatograph. An ODS column(4.6 mm i.d.×100 mm) was used, and the mobile phase consisted of 1.4×10(-2) M tetrabutylammonium bromide and phosphate buffer (pH 8,5×10(-3) M) in a mixture of 52 vol% methanol and 48 vol% distilled water. To 7.5ml of sample solution, 1 ml of citrate buffer solution(2 M, pH 5.4) and 1 ml of nitroso-NW acid(4×10(-3) M) were added. After 10 min, 0.5 ml of 2×10(-3) M EDTA was further added, and the resultant solution was diluted to 10 ml with distilled water. One hundred μl of the solution was injected on to the column. Detection was made on a UV detector at 368 nm. The calibration curve was linear in the range of (125)×10(-7) M of cobalt. By the proposed method, cobalt contents in four commercial nickel salts, Ni(NO(3))(2) · 6H(2)O, NiSO(4) (NH(4))(2) SO(4)·6H(2)O, NiSO(4)·6H(2)O, and NiCl(2)·6H(2)O, were determined to be (0.0030.06)% with relative standard deviation of 1.3% (seven determinations of the nitrate salt)