摘要:

Column-switching ion chromatography was adopted in developing a method for simultaneous determination of multiple components in food. The chromatographic base line was not influenced by column switching. Food samples containing acetate, sorbate, benzoate, saccharin, Cl−, PO43-, and citrate have been determined simultaneously by this technique. Experimental conditions are given.

ISSN:0003-2719    

DOI:10.1080/00032719608001526

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Methods for determining chromium (VI) at the ppb level, in tap water and ground water, were developed. These make use of anion exchange resin beads or anion exchange membrane filters to preconcentrate the Cr(VI) and separate it from interfering cations. The color is developed by reaction with diphenylcarbazide and the quantitation is carried out using a portable UV/Vis spectrometer, in the liquid or solid phase, or by visual color matching. These methods are suitable for use in the field.

ISSN:0003-2719    

DOI:10.1080/00032719608001527

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Tellurium was determined spectrophotometrically at 635 nm and pH 5.3 based on its catalytic reduction of Toluidine Blue in the presence of Te(IV) by using a flow -injection system. Under the optimized experimental conditions, the detection limit is 60 ng/ml of tellurium ion and the linear range is 80–3800 ng/ml (110 μl, injection). The relative standard deviation of 10 replicate measurements is 1.5% for a 1.5 μg/ml of tellurium. The sampling rate is 25 h-1.

ISSN:0003-2719    

DOI:10.1080/00032719608001528

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An ICP-OES method for applying a macroporous ploy(vinylethy-lenediamine) chelating resin to preconcentrate and separate trace Ga(III), In(III), Bi(III), Sn(IV) and Pb(II) ions from solution samples is established. The analyzed ions of 0.05–0.5 ug/ml can be enriched by the resin of 0.07-g amount at a 1.0 ml/min of flow rate at pH 5, and can be also desorbed with a 10 ml of 3 M HClO4from the resin column, with recoveries over 96%. The chelating resin reused 7 times can still adsorb quantitatively the Ga, In, Bi, Sn and Pb ions, and a 500-fold excess of Fe(III), Al(III), Mn(II), Cu(II), Ni(II), Zn(II) and Cr(III) caused little interference with the enrichment and determination of these ions. The RSDs of the proposed method are in the range 1.2–5.5% for each analyzed ion. The recoveries of added standard in real solution samples are between 94% and 100%, and the concentration of each ion in a mineral sample detected by the method is in good agreement with the analyzed value by ETAAS method.

ISSN:0003-2719    

DOI:10.1080/00032719608001529

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The effect of an aluminum matrix on the determination of B, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Si and Zn was studied. These elements are expected to be present in high purity Al base materials. 45 spectral lines of these elements were scanned in a spectral window of 60 pm. Background equivalent concentrations were calculated and compared with existing data. Interference free spectral lines, one for each element, have been recommended to be used for analysis. Depression effects due to the Al matrix were calculated at the selected lines.

ISSN:0003-2719    

DOI:10.1080/00032719608001530

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Elemental analysis by Fast Atom Bombardment - Mass Spectrometry (FAB-MS) of biological and food samples has been used by several authors. However, the emission processes in FAB-MS in inorganic analysis have not yet been thoroughly investigated. In the present work, we have studied the effect of the probe material on the positive ion emission of elements found in different matrices, the probe materials that we have investigated are aluminum, gold, graphite and vitreous carbon. The nature of the probe material has a strong effect on the ion emission of several analytes. A vitreous carbon probe was found to provide the strongest analytical signal, its surface has a low porosity and therefore it can be easily cleaned for trace element determination. The composition of the sample matrix also has a strong effect on the analyte ion emission. A high concentration of proteins or of sodium suppresses the analyte signal. We have examined different modifications of the biological matrix to improve the analyte signal.

ISSN:0003-2719    

DOI:10.1080/00032719608001531

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608001532

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608001515

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor