摘要:

In this paper the absorption spectra of 4f electron transitions of the system of holmium with 2-isobutylformyl-1,3-dione-indan and TX-100 have been studied by normal and derivative spectrophotometry. The molar absorptivities are 98 (at 450 nm) and 21(at 460 nm) 1.mol−1. cm−1, respectively. The use of the second derivative spectra, eliminates the interference by other lanthanides and improves the sensitivity for holmium determination. The derivative molar absorptivity is 558 1. mol−1.cm−1. The calibration graph was linear up to 25μg/ml of holmium. The relative standard deviation evaluated from ten independent determinations of 8.0 μg/ml holmuim is 1.0%. The detection limit, obtained from the sensitivity of the calibration graph and for 3 Sb(Sb= standard deviation of a blank without holmium, n = 11), was found to be 0.31 μg/ml of holmium. The quantification limit, obtained for 10 Sb, was 1.0 μg/ml of holmium. A method has been developed for determining holmium in a mixture of lanthanides by means of the second derivative spectra and the analytical results obtained are satisfactory.

ISSN:0003-2719    

DOI:10.1080/00032719608002241

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A new on-line precolumn preconcentration method for the determination of EPA priority pollutants (PAHs) in river and sea water has been developed. The retention time for each PAH in the precolumn has been determined for several percentages of organic solvent (acetonitrile) in the sample. This is very important because recoveries show a great dependence on this parameter.

ISSN:0003-2719    

DOI:10.1080/00032719608002242

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A new method for the direct determination of trace mercury in aqueous solution with high selectivity and sensitivity is reported. In the presence of Triton X-100 and NH3.NH4Cl medium, a new chromogenic reagent p-azobenzenediazo- aminoazobenzene sulfonic acid (ADAAS) forms a red complex with mercury(II). The molar absorptivity is 1.76×105l. mol−1cm−1at 528 nm. Beer's law is obeyed in the range of 6.0×10−8- 6.0×10−6mol/L for Hg(II). Only cadmium interferes in the determination of mercury, and it can be eliminated by masking with nitrilotriacetic acid. The proposed method has been successfully used for the determination of trace amounts of mercury in waste water.

ISSN:0003-2719    

DOI:10.1080/00032719608002243

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Derivatives of some nitrogen-sulfur mixed donor and tetraaza macrocycles withvic-dioxime units incorporated into dichloro glyoxime have been used in order to investigate if nickel, cobalt and copper ions can be quantitatively determined via a potentiometric titration method.

ISSN:0003-2719    

DOI:10.1080/00032719608002244

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Iron(II) chelate complexes of 1,10-phenanthroline (Phen), 4,7-dimethyl-1,10-phenanthroline (DMPhen), 3,4,7,8-tetramethyl-1,10-phenanthroline (TMPhen) and 4,7-diphenyl(batho)-1,10-phenanthroline (DPPhen) were prepared and identified by means of absorption and infrared spectroscopy. The characteristic elution of these complexes on an Inertsil ODS column as well as their separation was investigated by ion-paired reversed phase chromatography. Some parameters influencing the separation such as composition of eluent, counter ion species and their concentrations were also studied. It was found that acetonitrile/water (80/20, v/v) containing 0.06 M HC1O4gave the best separation for each complex.

ISSN:0003-2719    

DOI:10.1080/00032719608002245

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608002246

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608002230

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor