NSWC/WOL/TR 75-3 5 



4.3.2 Dissolved Constituents 



4.3.2.1 Metallic Ions 



Determination of metallic ions in water from the dissolved 

 explosion products can be accomplished by many methods. A recent 

 study shows that atomic absorption appears to be the best technique 

 for the analysis of trace metals in marine waters. ^2 Th e method is 

 simple, rapid, and applicable to a large number of metals in surface 

 waters, domestic and industrial wastes, and saline waters. 



However, the concentration of the metals in the water samples 

 may be below the practical limits of detection by atomic absorption 

 (Table 5) . Although the recently developed graphite furnace technique 

 has increased the limits of detection by several orders of magnitude, 

 severe problems have been encountered in the direct analysis of trace 

 metals in seawater with this technique. Therefore, when trace metals 

 are present in low concentration, they must be concentrated in some 

 manner before analysis by atomic absorption analysis (see Section 

 4.2.3) . 



Table 5 



SENSITIVITY OF ATOMIC ABSORPTION 



*The maximum permissible concentration in water without constituting 

 a hazard in the marine environment. 



**The concentration that produces an absorption of 1%. 



22 



Lai, M. G., "Evaluation of Analytical Techniques for the Determina- 

 tion of Trace Elements in Marine Waters", Naval Ordnance Laboratory, 

 NOLTR 74-116, 24 July 1974. 



48 



