摘要:

A flow injection system is proposed for the rapid and sensitive determination of ultra trace amounts of osmium as osmium tetroxide. The method is based on the catalytic effect of osmium on the oxidation of gallocyanine by hydrogen peroxide at 30°C. The effect of important parameters, such as pH, reagent concentration, and flow rate, sample volume, temperature and length of the reaction coil are reported. Osmium in the range of 0.010 - 100 ng.ml−1can be determined at a rate of 35 ± 5 samples per hour. The limit of detection was 0.003 ng.ml−1. The relative standard deviation for the determination of 1.00 ng.ml−1of Os(VIII) is 1.5%. A system is proposed for elimination of potential interferences. The method was applied to the determination of osmium in real samples.

ISSN:0003-2719    

DOI:10.1080/00032719608001467

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A method to determine phytic acid within urine in the range 0.15–2 mg/l is reported. The method is based on the ICP atomic emission spectrometric determination of phosphorus, after previous separation and concentration of phytic acid using the anionic resin AG1-X8. The method has been applied successfully to determine phytic acid in synthetic urine and human urine.

ISSN:0003-2719    

DOI:10.1080/00032719608001468

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The sensitivity of the phenolphthalein spectrophotometric method for the determination of the purity of β-cyclodextrin (β-CD) was studied under different conditions. The alkalinity of the phenolphthalein colorimetric solution and the concentration of phenolphthalein in the colorimetric solution affected the sensitivity of the spectrophotometric readings and the linear range of the calibration curve. The optimum conditions for a basic working solution at pH 10.53 were that 5 ml of phenolphthalein working solution and 5 ml of sodium borate working solution were made up to a total 50 ml of phenolphthalein colorimetric solution, and the optimum conditions for a basic working solution at pH 11.23 were that 5 ml of phenolphthalein working solution and 3 ml of sodium borate working solution were made up to 50 ml total solution. Because of the instability of the absorbance of phenolphthalein solutions, it is suggested that at over 98% purity, β-CD should be determined by other more accurate methods.

ISSN:0003-2719    

DOI:10.1080/00032719608001469

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The recovery of palladium(II) from acidic aqueous solutions and sea water using 4-phenylthiosemicarbazide (HPTS) and oleic acid surfactant (HOL) has been studied by ionic flotation. Hydrogen ion concentration, foreign ions, temperature and reagent concentrations have been investigated for attaining the maximum efficiency of palladium(II) flotation. HPTS is used to develop a rapid and sensitive method for the spectrophotometric microdetermination of Pd(II). Various analytical parameters have been evaluated. Beer's law is obeyed over 2.0–14.5 ppm concentration range. The molar absorptivity of the formed 1:1 species is 0.49 x 104L mol−1cm−1at 300 nm. The ligand protonation constant and the stability constants of its complexes with Pd(II) have been determined potentiometrically. The method is successfully applied to determine directly the added Pd(II) to sea water without flotation. Square-planar geometry was proposed for the isolated solid complex. Also, the flotation mechanism is suggested.

ISSN:0003-2719    

DOI:10.1080/00032719608001470

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The “in-line” and “on-line” linearity terms of a linear calibration are defined. “On-line” linearity, which is calculated from the standard deviation of the slope, is proposed as a performance characteristic for the analytical method. The relation between the precision of an analytical result, and the analytical sensitivity and “on-line” linearity of the corresponding chemical calibration is established. The simplified equation that is obtained makes it possible to rapidly estimate the standard deviation with a sufficient degree of freedom, even when few analysis replicates are available. An indication is also given of the suitable equation for a more accurate calculation. The use of the two linearities, both “in-line” and “on-line”, is discussed, concerning the determination of the linear calibration range, for those techniques with which curvatures are obtained when the concentration of the standard analyte exceeds a particular value.

ISSN:0003-2719    

DOI:10.1080/00032719608001471

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608001472

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608001473

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608001474

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608001456

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor