The Carlo-Erba NA

Verado, D.J., P.N. Froelich, and A. McIntyre. 1990. Determination of organic carbon and nitrogen in marine sediments using the Carlo Erba NA-1500 Analyzer. Deep-Sea Research 37 157-165. 

Fig. 4.13 The Carlo-Erba NA 1,500 CNS analyzer for the determination of total carbon, nitrogen,...

For phytoplankton particulate organic carbon (POC) and particulate nitrogen (PON) determination, some suspended matter was collected on precombusted (450°C) Whatman GF/F filters, dried at 60°C and stored in polystyrene Petri dishes until analysis. POC and PON were analyzed with a Carlo Erba NA 2000 elemental analyzer. The analytical error of the... 

The NA 1500 analyser supplied by Carlo Erba is capable of determining these elements in 3-9min in amounts down to lOmg L 1 with a reproducibility of 0.1%. A 196 position autosampler is available. 

PVG disks with thickness 0.4 mm. Corning Co., Code-7930, have been used. PVG has been prepared by phase separation of an alkali borosilicate glass and subsequent acid leaching. The NA measurement has been performed at 77K on a Sorptomatic 1900 (Carlo Erba Instruments). The sample has been degassed at 393 K for 8h. Adsorption and desorption isotherms were measured over a range of relative pressures P/Pq from 0 to 1.0. 

The two zeolite-rich samples were previously Na-exchanged by percolation with a 1 M Na solution, prepared from reagent grade Carlo Erba NaCl, up to complete elution of the parent cations, other than Na i.e., K, Mg, Ca. In order to minimize the amount of residual impurities in the zeolite, elution was improved using a solution made with extra pure NaCl (Aldrich Chemicals, purity 99.999%). 

The specific surface area of the freeze-dried samples of La-montmori1 Ionite, La-Ni-rnontmori1 Ionite as well as the original Na-montmori1 Ionite were measured by the one-point-method in a Carlo Erba-Sorpty 1750 system by N2 adsorption at -196°C. The results are summarized in Table 1, It can be seen that the surface area of Na-montmori1 Ionite increases substantially upon pillaring with La from 17.1 m. g-l to 35.4 m. g" . On the... 

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