Eizen Ishii

Determination of sulphate and phosphate by flow-injection analysis using a barium chloranilate packed column

SummaryA flow-injection analysis of sulphate using a reaction column packed with barium chloranilate (BaCh) is described. The chloranilate ion released by the reaction is monitored at the isosbestic point (310 nm) of chloranilate. An aqueous solution of 2-propanol (60%) is used as the carrier solution at a flow-rate of 1 ml . min−1. The linear dynamic range of the detection system is approximately 2.5×10−6∼1.0×10−3 mol/l per 10 μl sample injection. The time required for a determination is only 20 s per sample injection. The method has also been applied to the amplified determination of phosphate by reaction with molybdate resulting from the decomposition of molybdophosphate (H3PO4.MoO3) extracted.

Photometric determination of selenium with ferrocene

A sensitive spectrophotometric method for the determination of selenium has been developed. The method depends on a redox reaction between selenious acid in 8M hydrochloric acid and a chloroform solution of ferrocene. One mole of selenious acid produces 4 moles of ferricenium ions, which are then oxidized by bromine water. The resulting iron(III) is reduced to iron(II) and determined with 1,10-phenanthroline. The relative standard deviation for 20 mug of selenium was 1.1%. The apparent molar absorptivity of the final solution, referred to selenious acid, is 4.23 x 10(4) 1. mole(-1). cm(-1) at 512 nm. This method has been used to determine selenium in copper metal.

Electrochemical gas sensors using electrolytic films of poly(ethylene oxide)/Zn, Cu, Ni trifluoromethane sulphonates for flow injection analysis of nitrogen dioxide

Abstract Au/poly(ethylene oxide)nM(CF3SO3)2/M (M = Zn, Cu, Ni) galvanic gas sensors, consisting of a disk 13 mm in diameter and 1.1 mm thick, have been developed by using a polymeric electrolyte film (0.1 mm thick). The polymeric films are made by mixing with an acetonitrile solution both M(CF3SO3)2 and poly(ethylene oxide) (m.w. ≈ 6 × 105). The working electrode (25 nm thick) is made by sputtering gold in an argon atmosphere. Of the three kinds of sensors, the zinc one (n = 55) shows the greatest sensitivity. For the zinc cell, the maximum response appears within 3 s after the sample (2.6 ml) is injected into the nitrogen carrier stream, flowing at a rate of 28 ml min−1; the response returns to the baseline within 3 min at the longest. The maximum current flowing in the external circuit is linearly related to the concentration of NO2 in the range 0.02–1 ppm at ambient temperature.

Comparative study of barium salts of 2,5-dihalo-3,6-dihydroxy-p-benzoquinone as reagents for the spectrophotometric determination of sulphate

Abstract The spectrophotometric determination of sulphate employing barium salts of fluoranilic, bromanilic or iodanilic acid was studied. The synthesis of fluoranilic and iodanilic acids and the preparation of the barium salts of the haloanilic acids as reagents are described. Suitable reaction conditions for linear calibration were established. The molar absorptivities for the reaction products of the Ba haloanilates with sulphate were between 1.87 × 10 4 and 2.78 × 10 4 1 mol −1 cm −1 at their absorption maxima. The relative standard deviation at 5 μg of sulphate was

Densitometric detection of fluorescence enhanced by using a transparent polymer film in TLC.

薄層クロマトグラフィーの蛍光デンシトメトリー検出において,展開直後のプレートを,透明な高分子フィルムで覆い,その状態で展開溶媒{アセトンートルエン(1:8)混液}を熱風を用いて一定量揮散させた後に測定すると蛍光強度が増加し,更に安定することを見いだした.溶媒の揮散時間を15分とし,フィルムの材質にはポリ塩化ビニリデンを,固定相にはシリカゲルを用いた.試料としてダンシル化ジエチルアミンを用いた場合の蛍光強度は,溶媒を完全に揮散させた後に測定する通常の方法と比較すると,17倍増加し,検出下限は15pmol/zoneであった.

Chemical amplification method for the determination of selenious acid with bismuthiol II

SummaryAn amplification method is described for the determination of selenious acid with bismuthiol II. A 9.4 fold amplification is achieved.

Determination of copper(II) by kinetic-catalytic oxidation of ferrocene

This paper reports on the photometric determination of copper (II) with 1,10-phenanthroline by the iron (III) formed from the oxidative decomposition of ferricenium ions