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A fully automated flow injection (FI) system utilizing the extraordinary oxidation power of bromine monochloride (BrCl) for the transformation of dissolved mercury species to Hg(2+) and oxidation of dissolved organic carbon (DOC) has been developed and coupled to cold vapor (CV) atomic fluorescence spectrometry (AFS) for highly sensitive mercury detection. The system can be applied to natural waters, sea water as well as freshwater and provides a detection limit as low as 16 pg Hg l(-1) from a sample volume of 7 ml. The relative standard deviation is about 4-10%. A 3-fold measurement of one sample is completely processed within 15 min. Dissolved organic carbon, chloride and iodide ions are tolerated in concentrations of 15 mg DOC l(-1), >21 g Cl(-)l(-1), and 10 mg I(-)l(-1). Validation of the proposed method yielded a good recovery of total mercury in a moorland water sample and in the certified reference material ORMS-3, river water. Investigation of eight real water samples with mercury concentrations in the range of 0.3-1.4 ng l(-1) also confirmed the suitability of the proposed method.

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PURPOSE: In this manuscript, the safety and efficacy of adjuvant interferon alfa 2b treatment of uveal melanoma is described. PATIENTS AND METHODS: A total of 39 patients (23 male and 16 female, mean age 56.5 years, range 35-78 years) with uveal melanoma were treated with interferon alfa 2b, 3 million units three times a week subcutaneously for 1 year after therapy of the primary tumor. In all patients age, gender, primary melanoma data, therapeutic interventions, treatment side effects and outcome were documented. RESULTS: Of the 39 patients, 31 (80%) finished the treatment as scheduled after 1 year. In 18 patients (46%) the initial dose had to be reduced due to leucopenia, thrombopenia, cardiac symptoms, elevated of liver function or vertigo (WHO grade I-III). In eight patients, therapy had to be withdrawn because of serious side effects (five patients) and the appearance of metastases (three patients). Neither a univariate approach nor a multivariate approach could show a protective effect of interferon treatment on survival. CONCLUSIONS: Adjuvant treatment of uveal melanoma with interferon alfa should be abandoned until the question of dose and administration for cutaneous melanoma is solved.

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Low lead levels in the femurs of mice fed with a lead-depleted diet have been determined by use of electrothermal atomic absorption spectrometry with Zeeman-effect background correction. The method is based on the use of Mg(NO3)2/Pd as matrix modifier which enables significant reduction of the spectral interferences prevalent if chemical modifiers based on NH4H2PO4 with either Ca or Mg are used for samples rich in Ca3(PO4)2 matrix. The method was developed and validated by use of the NIST standard reference material 1486 bone. Bones were decomposed in a pressurized microwave-heated system using 70% nitric acid. Forty-three mice femurs, with a mass of 74.62 +/- 12.54 mg, were dissolved in concentrated nitric acid. The lead results found in SRM 1486 (1.25 +/- 0.15 microg g(-1), n = 9) were in good agreement with the certificate (1.335 +/- 0.014 microg g(-1)). Recoveries of 200 ng lead added to the SRM before or after digestion were 99.0 +/- 1.4% and 98.5 +/- 1.6%, respectively. The lead detection limit in bone samples is 0.06 microg g(-1) dry mass. This method is, therefore, suitable for the determination of very low lead levels (0.06-0.20 microg Pb kg(-1) bone) in the femurs of mice fed a diet with lead level of < 20 microg kg(-1).

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A graphite-furnace AAS method using the stabilized-temperature platform furnace (STPF) concept, mixed palladium and magnesium nitrates as chemical modifier and Zeeman background correction has been applied to the direct determination of As, Cd, Pb and Se in highly mineralized waters used for medicinal purposes. These contain 20-40 g/l. concentrations of salts, mainly sodium and magnesium chlorides, bicarbonates and sulphates. The use of a pre-atomization cool-down step to 20 degrees in the graphite-furnace programme reduced the background absorption. Increasing the mass of magnesium nitrate modifier to 5 times that originally proposed improved the analyte peak shape. Under these conditions, no interference was found in analysis of the chloride/bicarbonate type of water, but the sodium and magnesium sulphate type of water had to be diluted, and even then an interference remained. Calibration with matrix-free standard solutions was used, but use of spike recovery is strongly recommended for testing the accuracy. The limits of determination (4.65sigma) of the proposed method for undiluted samples are 2.0 mug/l. for As, 0.05 mug/l. for Cd, 1.0 mug/l. for Pb and 1.5 mug/l. for Se.

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