Determination of uranium in urine - measurement of isotope ratios and quantification by use of inductively coupled plasma mass spectrometry.

For analysis of uranium in urine determination of the isotope ratio and quantification were investigated by high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS). The instrument used (ThermoFinniganMAT ELEMENT2) is a single-collector MS and, therefore, a stable sample-introduction system was chosen. The methodical set-up was optimized to achieve the best precision for both the isotope ratio and the total uranium concentration in the urine matrix. Three spiked urine samples from an European interlaboratory comparison were analyzed to determine the (235)U/(238)U isotope ratio. The ratio was found to be in the range 0.002116 to 0.007222, the latter being the natural uranium isotope ratio. The first ratio indicates the abundance of depleted uranium. The effect of storage conditions and the stability for the matrix urine were investigated by using "real-life" urine samples from unexposed persons in the Netherlands. For samples stored under refrigeration and acidified the results (range 0.8 to 5.3 ng L(-1) U) were in the normal fluctuation range whereas a decrease in uranium concentration was observed for samples stored at room temperature without acidification.

Determination of butyltins in harbour sediment and water by aqueous phase ethylation GC-ICP-MS and hydride generation GC-AAS.

Sediment and water samples have been collected between 1992 and 1995 for evaluating butyltin contamination in two marinas from the coastal area in The Netherlands, two years after the ban of TBT. Sediments extracts were analysed by capillary gas chromatography-inductively coupled plasma-mass spectrometry. Sediment concentrations for TBT showed no trend of decrease between 1992 and 1995 and were extremely high in the marina secluded from tidal action; 17.5 +/- 8.0 microg g(-1) and much lower for the marina with tidal action; 0.117 +/- 0.073 microg g(-1). High ratios between TBT and DBT in the sediments indicate that degradation mechanisms in the sediments are of minor importance. Dissolved butyltin compounds were analysed in water by means of gas chromatography-atomic absorption spectrometry. Water concentrations of TBT showed no clear trend of decrease between 1992 and 1995 and were high in the marina secluded from tidal action; 139 +/- 166 ng litre(-1) but much lower for the marina with tidal action; 48 +/- 98 ng litre(-1). An active degradation mechanism during summer periods was indicated by low (<1) TBT/DBT ratios in the water phase of the marina secluded from tidal action.

Radioimmunoassay for Lys8, Asn9, neurotensin 8-13: tissue and subcellular distribution of immunoreactivity in chickens.

A sensitive and specific radioimmunoassay (RIA) for Lys8, Asn9, neurotensin 8-13 (LANT-6) has been developed which utilizes 125I-labeled LANT-6 and rabbit antisera raised towards conjugates of synthetic LANT-6 and bovine thyroglobulin. The antiserum described (TG-22) allows the detection of ca 100 fmol of LANT-6 and crossreacts less than 0.01% with chicken or bovine NT. Dose-response relationships for the native (chicken) and synthetic peptides were indistinguishable. Using this assay the distribution of immunoreactive LANT-6 (iLANT-6) through various tissues of the chicken was studied and compared with that of chicken NT (iNT) determined by RIA. Both iNT and ILANT-6 were found primarily in the brain and gastrointestinal tract, however, their regional distributions were found to differ. Subcellular distribution studies in homogenates of chicken brain indicated that both iNT and iLANT-6 were associated with synaptosome-like and vesicle-like particles. In homogenates of small intestine, pancreas and colon iNT and iLANT-6 appeared to be within osmotically sensitive, sedimentable particles. Analyses using high pressure liquid chromatography established that chicken iLANT-6 co-eluted with the synthetic peptide and that similar substances were present in extracts of rat brain and intestine. These results are consistent with "messenger' roles for these peptides.