摘要:

A kinetic-spectrophotometric method is presented for the determination of trace amounts of selenium (0.010 – 0.500 μ.ml−1), based on the catalytic effect of Se(IV) on the reduction of Gallocyanine by sodium sulfide, which yields a colorless product. The reaction is followed spectrophotometrically by measuring the absorbance change at 620 nm and 30 °C. The detection limit is 0.002 μ.ml−1. Se(VI) can be reduced with hot hydrochloric acid to Se(IV), allowing determination of total selenium. The variables which affected the reaction rate were fully investigated and the optimum conditions were established. The relative standard deviation for 50 ng.ml−1of selenium was 2.5% (n=6). The method was applied to determination of Se(IV) in real samples.

ISSN:0003-2719    

DOI:10.1080/00032719508000326

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A simple, sensitive and specific quantitative HPLC method for the analysis of the fungicide folpet in grapes is described. The method is based on a simple extraction step, high performance liquid chromatographic separation using HPLC-RPC8 column and UV detection. Using this approach, residue quantities down to 0.005 mg/kg were analyzed.

ISSN:0003-2719    

DOI:10.1080/00032719508000327

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A high surface area silica has been modified with 3-(Trimethoxysilyl)-1-propanethiol groups. The silica retains its surface area after the treatment. The characteristics of this modified silica and its application to the preconcentration separation of cobalt and nickel prior to determination by Graphite Furnace Atomic Absorption Spectrometry (GFAAS) are described. Both batch and column methods were studied. The experimental parameters such as the effect of pH of the sample and eluent, flow rate of eluent, the column and the amount of silica on sorption and elution has been investigated.

ISSN:0003-2719    

DOI:10.1080/00032719508000328

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A model to estimate the tolerance level of interfering substances for analytical procedures, applying the linear simple regression, is proposed. The confidence interval on the analytical signal for the selected concentration value to check the interference, is calculated using the calibration data set. The tolerance levels of molybdenum, aluminium and iron in the spectro fluorimetric determination of boron with Alizarin Red S by means of direct, synchronous and first- and second-derivative methods, are estimated. The adequate selection of an analyte concentration for the interferent test is discussed.

ISSN:0003-2719    

DOI:10.1080/00032719508000329

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719508000330

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719508000332

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor