NSWC/WOL/TR 75-35 



Lithium 



Lithium in seawater may be directly determined by atomic 

 absorption without separation and concentration. 



Zirconium 



Any zirconium introduced into the natural waters will be 

 rapidly hydrolyzed at the pH of the waters (seawater and fresh water) 

 to a colloidal hydrous oxide which will be readily precipitated. 

 Therefore, the concentration of soluble Zr is expected to be extremely 

 low. The co-precipitation technique with iron hydroxide at a pH of 

 9.0 to 9.5 described by Slowey et al^ is used for the concentration 

 of Zr in water. Each sample previously filtered through 0.45y filter 

 is co-precipitated three times by the addition of 12 mg of Fe + ^ per 

 liter of sample. The pH is then adjusted to 9 by the addition of 

 ammonium hydroxide. The sample is filtered through Millipore filters. 

 The precipitate is dissolved in 9N HCl and the iron extracted with 

 d iisopropylether . The sample is then evaporated to almost dryness 

 and diluted to 10 ml with 2% HF. With this procedure a sensitivity 

 of 0.1 ppm can be attained. 



Direct analysis of metals by atomic absorption generally costs 

 $15 per element. The cost will increase several times if concentra- 

 tion procedures are required. 



4.3.2.2 Explosives 



Very few reliable methods for the analysis of explosives at low 

 concentration (parts per million) in water and in sediment have been 

 developed. Procedures for several common types of explosives (TNT, 

 RDX, Tetryl, and ammonium perchlorate) were established by Hoffsommer 

 et al at NAVS URFWPNCEN based on the use of gas chromatography and the 

 ion specific electrode. A method for the analysis of HMX in water 



25 



Slowey, J. F., Hayes, D. , Dixon, B. and Hood, D. , "Distribution 



of Gamma Emitting Radionuclides in the Guld of Mexico", Symposium 



on Marine Geochemistry, University of Rhode Island, Occasional 



Publication No. 3, Aug 1965. 



Hoffsommer, J. C. , Glover, D. J., and Rosen, J. M., "Analysis of 

 Explosives in Sea Water and in Ocean Floor Sediment and Fauna", 

 Naval Ordnance Laboratory, NOLTR 72-215, 11 Sept 1972. 



50 



