摘要:

Molybdenum(V) has been found to react with thiocyanate and N1-hydroxy-N1,N2-diphenylbenzamidine (HDPBA) to form a 1:3:1(Mo:SCN−:HDPBA) complex with a molar absorptivity of 13100 M−1cm−1at 470 nm. The complex is quantitatively extractable into 2.5% (v/v) amyl alcohol in benzene from 4–6 M hydrochloric acid solutions and the system obeyed Beer's law in the concentration range of 0.5–9.6 μg mL−1of Mo. Optimum conditions for the extraction and determination of molybdenum have been established and a precise, sensitive and highly selective method has been developed for the determination of molybdenum(V) by solvent extraction and spectrophotometry. The method has been successfully applied to the determination of molybdenum in standard steels and synthetic matrices.

ISSN:0003-2719    

DOI:10.1080/00032719508002774

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

An improved and sensitive gas chromatographic method has been established for the determination of four dialkyl thiophosphates including dimethyl phosphorothioate, diethyl phosphorothioate, dimethyl phosphorodithioate and diethyl phosphorodithioate. The method is based on the derivatization of the thiophosphates with pentafluorobenzyl bromide, using hexadecyltrimethylammonium bromide as a phase transfer catalyst. The resulting derivatives were separated on an SE-54 capillary column and detected by an electron-capture detector. Several parameters affecting the derivatization of the related thiophosphates were investigated. Determinations of the thiophosphates were attainable at pmol levels. The detection limits (signal to noise ratio of 5) of dimethyl phosphorothioate, diethyl phosphorothioate, dimethyl phosphorodithioate and diethyl phosphorodithioate in aqueous sample were at about 8.3, 6.0, 5.7 and 5.6 nM, respectively. Application of the method to the analysis of the thiophosphates spiked in plasma, after simple ultrafiltration treatment, proved to be feasible.

ISSN:0003-2719    

DOI:10.1080/00032719508002775

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Cation exchange behaviour of Zn(II) on Dowex 50 W × 8 (H+form) resin has been studied in mixed solvents and non-aqueous HBr system. 20–90% organic solvents like Acetone, Methanol, Tetrahydrofuran, 1,4-Dioxane, Ethanol in conjunction with 0.2M or 0.5M HBr were used as eluants. Separation of zinc from binary mixtures containing Ga(III), Th (IV), Ce(III), Fe(III), Ba(II), Co(II), Cu(II), Mn(II), Ni(II), Ca(II), Ti(IV), Li(II), Na(I), K(I) have been studied. Separation of zinc from multicomponent mixtures have been accomplished. The proposed method has been applied for the analysis of alloys, environmental and pharmaceutical samples.

ISSN:0003-2719    

DOI:10.1080/00032719508002776

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719508002777

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719508002763

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor