Water handling systems chemical analysis

For seawater analysis, it is possible to pump the sample directly from the sea to a shipboard analyser. The sample can then be de-gassed in-line and handled in a shipboard flow system. This possibility, and the main practical, physico-chemical and interpretative aspects, were discussed in relation to the in situ spectrophotometric determination of seawater pH [9]. The attractive features and applications of shipboard flow injection spectrophotometric determinations are discussed elsewhere [10,11]. A compact, shipboard flow analysis system incorporating a LTV photoreactor has also been reported for the determination of total phosphorus in estuarine and marine waters [12]. Another way to sample seawater is to use a towed torpedo-shaped "fish," deployed off the crane arm of a hydrographic winch at a distance of 5 m from the ship, connected to a deck mounted pump by appropriate tubing. Filtration can be incorporated in-line and the filtered sample collected or pumped directly to the flow analyser [13]. This approach (Fig. 8.1) minimises contamination and preconditions the sample, as demonstrated in the chemiluminometric determination of iron(II) in surface seawater. 

Liquid anhydrous ammonia is used extensively as a coolant in heat exchange systems because of its chemical stability, low corrosiveness, and high latent heat of vaporization. However, anhydrous ammonia is readily contaminated during handling and storage. The gas chromatographic analysis of trace contaminants (O2, N2, CO, CH4, CO2, and water) in liquid ammonia was described by Mindmp and Taylor. An F M Model 5750 equipped with a Carle Microcavity Thermistor detector was used with dual columns for analysis. Table 9.3 lists the experimental parameters for both columns, which were conditioned for a minimum of 12 h at a temperature of 180°C and a... 

---