Fully automatic on-line separation preconcentration system for electrothermal atomic absorption spectrometry: determination of cadmium and lead in sea-water.

An automatic separation preconcentration system coupled to an electrothermal (graphite furnace) atomic absorption spectrometer is described. The preconcentration step is performed on a chelating resin microcolumn (Chelex-100) placed in the injection tip of the autosampler. A time based manifold with two- and three-way solenoid valves commanded by an eight channel microcomputer programmable controller is used for column conditioning, preconcentration and washing steps; no manual operations are involved. Elution is performed by the programmable graphite furnace autosampler and achieved in only one step. Operations involving complete and partial injection of the eluate into the graphite furnace are also discussed. The system was applied to the determination of Cd and Pb in near shore sea-water from Patagonia, Argentina. Detection limits of 1 and 8 ng l-1 were obtained for Cd and Pb respectively. Analysis of a certified reference material (CASS-3) showed good agreement with the certified values.

A survey of some trace elements in seaweeds from Patagonia, Argentina.

Cadmium and lead concentrations were determined in some common algal species living in the southernmost coasts of Argentina. Two different sampling areas were chosen: Gulf Nuevo, a locality being influenced by a developing industrial city, and Bay Camarones, a traditional harvest area for seaweed exploitation. Selected species of the genera Lessonia, Macrocystis and Gigartina, all of commercial interest, were collected from the harvest area, and analyses showed low levels of the metals in these species. Accumulation of Pb and Cd was also evident in other common brown seaweeds from the industrial site. Analysis of Al was included in this study due to an aluminum works near one of the sampling sites. High values of this metal ranging between 300 and 3000 mg Al/kg (dry basis) were recorded in the industrialized area. Amongst all of the species studied, Colpomenia sinuosa from Gulf Nuevo exhibited the highest values of aluminum. This preliminary survey showed that, except for Al, the levels of Cd and Pb were lower than those reported in same species of seaweeds from the polluted marine waters of the rest of the world.

Atomic absorption spectrometric determination of inorganic and organic arsenic in some marine benthic algae of the southern atlantic coasts.

Arsenic in the inorganic and organic forms was analyzed in species of marine macro-algae growing in the South Atlantic Ocean. Species of the genera Lessonia, Gigartina, Adenocystis, Leathesia and Colpomenia were investigated. Arsenic accumulation was found in all species studied. Total As content ranged from 5.3 to 56.9 microg As g(-1) and the levels of the inorganic forms ranged from 0.2 to 2.0 microg As g(-1). The complete analytical procedure was validated against a standard reference material (NBS, SRM 1572, citrus leaves) and the value obtained was in good agreement with the certified value. Some commercial seaweed products were also analyzed.