[Environmental lead exposure in the Venetian population from 1976-1992]. / Esposizione ambientale al piombo nella popolazione dell'area veneziana dal 1976 al 1992.

Blood lead levels observed in the general population of Venice and the surrounding area are reported for the period between 1976 and 1992. A time dependent decrease of blood lead levels is evident and parallels the step wise decrease of lead levels in gasoline which took place between 1981 and 1991. The observed lowering time trend of blood lead levels could possibly be ascribed, perhaps not negligibly, to technological improvements, the development of new analytical procedures and the continuous practice of quality control.

Determination of Cd, Co, Cu, Mn, Ni, Pb, and Zn by Inductively Coupled Plasma Mass Spectroscopy or Flame Atomic Absorption Spectrometry after On-line Preconcentration and Solvent Extraction by Flow Injection System

The concentrations of Cd, Co, Cu, Mn, Ni, Pb, and Zn in natural and sea waters are too low to be directly determined with by flame atomic absorption spectrometry (FAAS) or graphite furnace atomic absorption spectrometry (GFAAS). Specific sample preparations are requested that make possible the determination of these analytes by preconcentration or extraction. These techniques are affected by severe problems of sample contamination. In this work Cd, Co, Cu, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS) or by atomic absorption spectrometry, in fresh and seawater samples, after on-line preconcentration and following solvent elution with a flow injection system. Bonded silica with octadecyl functional group C18, packed in a microcolumn of 100-μl capacity, was used to collect diethyldithiocarbamate complexes of the heavy metals in aqueous solutions. The metals are complexed with a chelating agent, adsorbed on the C18 column, and eluted with methanol directly in the flow injection system. The methanolic stream can be addressed to FAAS for direct determination of Cu, Ni, and Zn, or collected in a vial for successive analysis by GFAAS. The eluted samples can be also dried in a vacuum container and restored to a little volume with concentrated HNO3 and Milli-Q water for analysis by ICP-MS or GFAAS.

Analytical problems in mercury analysis of seafood.

It is generally accepted that seafood represents one of the major sources of mercury to man. In this work two interlaboratory proficiency tests are described for the analysis of mercury in seafood. Thirty-seven public control and food industries laboratories participated in the first test, while 29 participants were included in the second one. Moreover, in order to clarify whether sampling of different edible muscle tissues of the same fish could affect the analytical results, the top, the central and the bottom portion of 28 fishes were examined. The different portions of fish showed no significant difference in mercury concentrations. Two different wet digestion methods (microwave oven and reflux in quartz vessels) were also tested in the case of 11 fishes. A systematic difference was observed between the two sets of results obtained with these digestion methods.