摘要:

The reaction between cyclohexan-1,2-dione bissalicyloylhydrazone and titanium(IV) has been studied spectrophotometrically. An orange complex (λ = 470 nm, ε = 1.49 × 1041.mol−1.cm−1) is quickly formed at pH 1–2.5 in a 3+2 V/V ethanol/water medium. Interferences (more than 65 species) have been investigated. In presence of some masking agents most of metal ions do not interfere. The orange complex has been satisfactorily used for the determination of titanium in amphibolites, granites, suspended matter, Portland cement, bauxite, cast iron and duraluminium alloy. The results are compared with those obtained using AAS and ICP methods.

ISSN:0003-2719    

DOI:10.1080/00032719308017981

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The electron impact mass spectra of fifteen 4-substituted PBN's and PBN itself have been obtained using the probe method. Strong molecular ion peaks were observed in most cases. Fragmentation follows two major pathways depending on the polarity of the substitutent: thetert-butyl bond breaks to produce either thetert-butyl cation or isobutylene. The latter route is analogous to the well known McLafferty rearrangement. Fragmentation to produce thetert-butyl radical is a minor route. Electron-donating polar substituents appear to enhance fragmentation to isobutylene.

ISSN:0003-2719    

DOI:10.1080/00032719308017982

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A preconcentration method is described for traces of copper, cadmium and lead from pure zinc metal by use of activated carbon. Ammonium salt of dithiophosphoric acid-o, o-diethylester is used to complex Cu, Cd and Pb. These chelates are sorbed on activated carbon. The traces sorbed on the carbon are determined by direct current arc atomic emission spectrography. The analytical error in the concentration range of 10−3–10−4% is less than 6% and relative standard deviation is below 10%.

ISSN:0003-2719    

DOI:10.1080/00032719308017983

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Two equations for justifying whether a FIA peak is a gamma peak or an exponentially modified Gaussian (EMG) peak or neither of them have been presented. From these two equations, the peaks of flow injection extraction and FIA with single-line and two-line manifolds obtained in this paper are gamma peaks.

ISSN:0003-2719    

DOI:10.1080/00032719308017984

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The interaction of 38 nonionic surfactants containing various hydrophobic moieties with dimethyl-β-cyclodextrin (DIMEB) was studied by charge transfer chromatography. DIMED modified the retention behaviour of each surfactant, however, the strength of interaction varied considerably. Both the lipophilicity and specific hydrophobic surface area of surfactants significantly influenced the strength of interaction. The presence of ester bond and double bond in the hydrophobic moiety of surfactants has impact on the complex formation.

ISSN:0003-2719    

DOI:10.1080/00032719308017985

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Suppressed ion-chromatography using Na2CO3/NaHCO3as eluent was applied to the determination of chloride, sulphate, nitrate and bromide in highly mineralised waters. The effect of different concentrations of hydrogen carbonate on the retention times of the determination of the four selected anions was studied. Depending on the total concentration of ionic species, dilution of the sample is recommended to obtain retention times approaching those of the anion standard. The stability of sample composition was not affected by the presence of iron(III) ions (up to 15 mgL−1).

ISSN:0003-2719    

DOI:10.1080/00032719308017986

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The described alkali flame ionization detector (AFID) differs from other designs by introducing the alkali salt into the detector in the form of an aerosol. The preheated, desolvated alkali aerosol salt is introduced into a dual hydrogen gas flame assembly. This detector shows no evidence of fatigue due to the constant delivery of salt into the detector, compared to the fixed alkali supply found in other versions, which can be depleted by vaporization and become easily contaminated. This AFID design also allows for operation as an FID by implementing a simple pneumatic procedure. This paper deals with the performance and optimization of the detector using a dual alkali salt aerosol flame design for organonitrogen and organophosphorus compounds. Detection limits were 23.5 pgN/sec for alachlor, 185 pgN/sec for dinoseb, and 4.83 pgP/sec to 10.1 pgP/sec for various pesticides studied. Selectivity ratios are tunable to 6.6 × 106gP/gC, 4.0 × 104gN/gC and 2.3 × 103gP/gN by establishing the appropriate detector gas flow rates.

ISSN:0003-2719    

DOI:10.1080/00032719308017987

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0003-2719    

DOI:10.1080/00032719308017970

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor