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Biomedical subjects

J Bettmer

Publications and source records attributed to J Bettmer.

4 recordsLinked to original sources
PubMed2002

Rapid separation of elemental species by multicapillary GC.

Multicapillary gas chromatography has been applied to the speciation of organomercury compounds. Basic investigation of the fundamental properties of multicapillary columns, to evaluate their potential and limitations as a rapid separation unit, are presented. For analysis of methylated and ethylated mercury compounds a complete separation can be performed within 45 s under isothermal conditions. The adaptation of the technique for use with a purge and trap system and with an element-selective plasma-emission detector results in a compact and effective system for mercury speciation. Results from analysis of certified reference materials were in good agreement with certified values within the significance levels.

Journal Article↗
PubMed2001

Removal of interfering elements in ICP-QMS for the determination of Pt, Rh, and Pd by chemically modified sample introduction capillaries.

New on-line methods developed for the determination of Pt, Rh, and Pd by inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS) include separation of elements which might lead to spectral interference in the quadrupole instrument. The fused-silica capillaries generally used for transport of the sample to mu-flow nebulizers have been chemically modified with ion-exchanger compounds to remove interfering elements such as Cu, Pb, or Hf. Characterization of the modification procedures by atomic-force microscopy showed that the quality of the quartz material and the kind of modification had a decisive influence on the yield of surface modification, and thus the exchange capacity of the capillaries.

Journal Article↗
PubMed2000

Modification of capillaries coupled to micro-flow nebulizers: a new strategy for on-line interference removal in inductively coupled plasma mass spectrometry.

The application of interference removal within modified silica capillaries for the introduction of liquid samples by a micro-flow nebulizer into an inductively coupled plasma quadrupole mass spectrometer is described using the example of (103)Rh and its mass interferences resulting from (63)Cu (ArCu(+)), (87)Rb (RbO(+)), (87)Sr (SrO(+)) and (206)Pb (Pb(2+)). A strong cation exchanger was covalently bound to the capillary surface and its ability to interact with cations in aqueous solution was investigated. At pH 7. 0 the interfering elements can be selectively adsorbed within the capillaries without hampering the elution of Rh. The capillaries are easily regenerated by flushing with 10(-3) M hydrochloric acid in order to exchange retained cations for protons. Calibrations show no significant difference between the absence and presence of interfering elements, so the detection limit for Rh of 6.0 ng l(-1) (3sigma) is not influenced by adding up to a 100-fold excess of interferents. The method developed is compared with a mathematical correction model for inductively coupled plasma mass spectrometry using the example of Rh determination in particulate car exhaust fumes and the results obtained are discussed.

Calibration↗