Yoshiaki Sasaki

The ion-pair formation between dodecylsulfate and ammine-complexes of copper(II), nickel(II), zinc(II), palladium(II) and platinum(II), and the extraction behavior of the ammine-complexes by using sodium dodecylsulfate

A micellar solution of sodium dodecylsulfate (SDS) exhibits the property of being separated into two phases due to a temperature change or the addition of salts. The ammine-complexes of copper(II), nickel(II) and palladium(II) reacted with the dodecylsulfate anion to form the corresponding ion-pair, and were extracted into the SDS gel phase. The SDS plays the roles of a pairing-ion for the ammine-complexes and of an extraction medium. The ion-pair extraction mechanism was investigated; the extractability of metals was given by the function of the solubility products of the ion-pairs. This method was applied to the mutual separation of Ni(II)/Cu(II) and Pd(II)/Pt(II). The driving force for the extraction was an electrostatic interaction between the cationic complex and the surfactant anion. The use of the SDS gel as ion-exchanger is also expected.

Spectrophotometric determination of copper(II) with carbon disulfide, a secondary amine and triton X-100

Abstract Copper(II) is determined by non-extractive spectrophotometry as a complex of butylene dithiocarbamate formed in situ by reaction between carbon disulfide and pyrrolidine in aqueous Triton X-100 medium. This method is similar to that with butylene dithiocarbamate as starting material in the sense of simplicity, sensitivity, precision and accuracy. Pyrrolidine is the best of seven secondary amines tested in this way for copper determinations.

Simultaneous kinetic determination of secondary amines and their isomers by a spectrophotometric stopped-flow method based on the formation of dialkyldithiocarbamates

Abstract Secondary amines react with carbon disulphide to form stable dialkyldithiocarbamates at high pH in aqueous Triton X-100 solution. The formation rates of dimethyl-, diethyl-, di- n -propyl-, diisopropyl-, di- n -butyl- and diisobutyldithiocarbamates and pyrrolidinedithiocarbamate were measured by a stopped-flow spectrophotometric method. The reaction rates were a function of the pH of the solution and depended on the size and structure of the amines. The rate of isoalkylamines was far slower than that of the n -alkyl analogues. Individual concentrations of amines were determined in a mixture of di- n - and diisopropylamine and in a mixture of diiso- and di- n -butylamine.

Separation of cadmium from a large amount of zinc by chloroform extraction with ethylxanthate

Abstract Traces of cadmium are quantitatively extracted with potassium ethylxanthate into chloroform from 0.25 mol dm -3 ammonia buffer (pH 9.5), which masks zinc.

Slotted composite right/left-handed strip lines for leaky wave antenna applications

Slotted composite right/left-handed (CRLH) strip lines (SLs) are proposed for leaky wave antenna (LWA) applications in which their radiation patterns are required to be controlled with beam steering function. The dependence of the leakage power from a slot on one of the ground planes of the CRLH SL is studied numerically for a balanced slotted CRLH SL and a possibility of achieving the optimum slot dimensions for wave-number-independent radiation is shown. A slotted CRLH LWA operating at 10.0 GHz with the Taylor radiation pattern with the backward radiation is demonstrated and the validity of the numerical data is confirmed.

Extraction—spectrophotometric determination of palladium with n-butylxanthate

Abstract Palladium (6–180 nmol) is extracted quantitatively with potassium n -butyl-xanthate into benzene from an aqueous phase containing EDTA, and determined spectrophotometrically at 290 nm. The molar absorptivity of the complex is 7.5 × 10 4 dm 3 mol -1 cm -1 .

Extraction—spectrophotometric determination of manganese(II) with xanthates

Abstract Manganese(II) (0.04–2 μmol) is extracted into chloroform from an aqueous phase at pH 6.5–9.0, containing a large excess of (n-butyl) xanthate and measured spectrophotometrically at 457 nm. The apparent molar absorptivity is 5.5 × 103 dm3 mol-1 cm-1. The extractability of the manganese complexes decreases in the order n-butyl = benzyl- ⪢ n-propyl- ⪢ ethyl- ⪢ methyl-xanthate. Interfering ions can be removed by a preliminary extraction with ethylxanthate. Ni, Co, Zn, Cd, Pb, Hg(II), Fe(III), As(III), Ce(III), Se(IV), V(V), Mo(VI), and the alkali and alkaline earth metals do not interfere.

Determination of thallium in gold deposits by graphite furnace AAS.

金中のタリウムを定量する際に,金試料の王水溶液を直接黒鉛炉AASにより測定すると塩化物イオン及び金イオンが著しく妨害する.そこで,前処理法について検討した.その結果,王水に溶解した金試料溶液中の金(III)を亜硫酸水又は亜硫酸ジメチルで金属金に還元した後沈殿分離し,次いで,濾液を蒸発乾固して塩化物イオンを除去すればよいことが分かった.この前処理法でAu/Tlの重量比が25000の王水溶液からタリウムを回収率96.7%,相対標準偏差3.2%(n=4)で分離定量できた.又,金めっき皮膜中の微量タリウムの定量も可能であった.