Intraregional classification of wine via ICP-MS elemental fingerprinting.

The feasibility of elemental fingerprinting in the classification of wines according to their provenance vineyard soil was investigated in the relatively small geographical area of a single wine district. Results for the Stellenbosch wine district (Western Cape Wine Region, South Africa), comprising an area of less than 1,000 km(2), suggest that classification of wines from different estates (120 wines from 23 estates) is indeed possible using accurate elemental data and multivariate statistical analysis based on a combination of principal component analysis, cluster analysis, and discriminant analysis. This is the first study to demonstrate the successful classification of wines at estate level in a single wine district in South Africa. The elements B, Ba, Cs, Cu, Mg, Rb, Sr, Tl and Zn were identified as suitable indicators. White and red wines were grouped in separate data sets to allow successful classification of wines. Correlation between wine classification and soil type distributions in the area was observed.

Ion exchange separation of strontium and rubidium on Dowex 50W-X8, using the complexation properties of EDTA and DCTA.

A chromatographic method for separation of strontium from rubidium, using the unique alkaline-earth metal complexation ability of the carboxylic acids EDTA and DCTA is proposed. The method was developed in order to improve the effectiveness of (87)Sr/(86)Sr isotope studies with ICP-QMS. Due to the isobaric overlap of (87)Rb with (87)Sr, strontium needs to be separated from rubidium prior to sample analysis with ICP-QMS. The method involves the retention of strontium, calcium, magnesium, and rubidium on Dowex 50W-X8 resin in its NH(4)(+) form, followed by elution of the divalent cations as metal EDTA or DCTA complexes. Because divalent cations have different EDTA and DCTA complex formation constants, it is possible to separate them under the correct conditions. Neither EDTA nor DCTA form complexes with alkali metals, thus rubidium remains retained by the column and is later eluted using HNO(3). Both EDTA and DCTA elution methods were tested with different concentrations of the elements to determine the effect of increased concentration on separation efficiency. The EDTA elution procedure was proved to be effective in separating strontium from both calcium and rubidium, while the DCTA method was found to be even more effective, because strontium is separated from all the elements involved in this study.

Distribution coefficients and ion exchange behaviour of some elements with Purolite S-950 in hydrochloric acid.

Equilibrium distribution coefficients, K(d), are presented for some elements in hydrochloric acid using the phosphonated polystyrene ion exchange resin Purolite S-950. A few possible separations using this resin are demonstrated by elution curves and separations of synthetic mixtures of some elements (Ru, Rh, Mo, I, Li, Te, Si, Y).

Behaviour of Mo, Al, As, Cs, Sn, Sb, Pd, Rh, Ru, Ge, Se and Te on the macroporous resin AG MP-1 in alkaline medium.

The behaviour of Mo and some other elements on Ag MP-1 in alkaline medium was investigated. Equilibrium distribution coefficients, K(d), are presented for Mo on the anion exchangers AG 1-X2, AG 1-X4, AG 1-X8 and AG MP-1, and for some elements on AG MP-1 in alkaline medium. An anion exchange chromatographic separation of Mo from some of these elements is described and some results obtained with this method are reported.

Determination of slopes of calibration lines in multi element XRF analysis of thin films using polychromatic excitation from Mo, Au, W, and Cr anodes and one standard.

An algorithm is described for the theoretical calculation of the slopes of calibration lines for the elements of the K-series in multi element X-ray fluorescence analysis of thin films using polychromatic excitation with X-ray tubes producing widely differing primary radiation intensity profiles. The mathematical equations used to calculate slopes as a function of atomic number are based on the fundamental relationship between fluorescent intensity and atomic number, fluorescent yield, concentration and mass absorption coefficients of the analyte for primary radiation. A normalisation procedure based on a single known slope in the series ensured that the calculated slopes were correct for the particular measuring conditions.

Separation of (203)Pb by ion-exchange chromatography on chelex 100 after production of (203)Pb by the Pb(p, xn)(203)Bi--> EC.beta+ (203)Pb nuclear reaction.

Bismuth radioisotopes, produced by 50-MeV proton bombardment of a lead target in a cyclotron, are separated from the lead target material by ion-exchange chromatography on a column containing 5.0 ml of Chelex 100. After a decay period of 24 hr, the (203)Pb formed in situ is eluted from the column and then separated from (200)Tl and (201)Tl on a second ion-exchange column containing 0.5 ml of Chelex 100. Separations are sharp and carrier-free (203)Pb is obtained.

Indirect spectrophotometric determination of BIDA, DISIDA, DTPA and MDP in labelled compounds.

N-(4-(n-butyl)-acetanilide)iminodiacetic acid (BIDA), N-(2,6-diisopropylacetanilide)iminodiacetic acid (DISIDA), diethylenetriaminepentaacetic acid (DTPA) and methylene diphosphonic acid (MDP) are used in labelling kits. The contents of BIDA, DISIDA or MDP of the 99mTc-labelled compounds can be determined (indirectly) spectrophotometrically with copper, eriochrome cyaanine R (ECC) and dodecylethyldimethylammonium bromide (DEDA) in a sodium barbital buffered system at pH 8.5. The calibration curves obey Beer's Law from 0 to 40 micrograms/25 mL for BIDA and DISIDA, 0 to 60 micrograms/25 mL for DTPA and 0 to 100 micrograms/10 mL for MDP.