CHAPTER 13 



SHIPBOARD CHEMISTRY 



13-1 GENERAL REMARKS.— Shipboard 

 chemistry employed in the analysis of sea 

 water samples is basically the same as that 

 carried out ashore. The seagoing chemist, 

 however, works under certain difficulties and 

 is subjected to some hazards that do not plague 

 his shore based counterpart. Obviously he 

 must be constantly alert to prevent damage to 

 delicate equipment, resulting from ship's mo- 

 tion, with possible injury to himself and his 

 shipmates. He must have sea racks to stow 

 many types of glassware, chemicals, samples, 

 and apparatus. His laboratory space is, of 

 necessity, limited and must be used to the 

 utmost. Efficient arrangement of equipment 

 will reduce unnecessary work and is vital to 

 the chemist and his assistants who may be 

 working in teams to keep ahead of a backlog 

 of samples. 



As explained in previous chapters, the most 

 common method of obtaining sea water samples 

 is by means of Nansen bottles. The samples 

 are analyzed by the methods given in this 

 chapter. Nearly all analyses for various con- 

 stituents involve comparison by one method or 

 other with a standard or sample of known value. 



Additional information on the methods given 

 may be found in the references listed at the 

 end of part I. 



13-2 GENERAL LABORATORY EQUIP- 

 MENT. — Shipboard chemistry laboratories 

 require certain basic equipment regardless of 

 the types of anah'ses being performed. This 

 equipment also is utilized for biological and 

 geological work at sea. Lists of equipment 

 needed to carry out specific analyses are given 

 with each method described in tliis cliapter. 



13-3 Laboratory Furniture. — The properly 

 equipped laboratory requires permanently in- 

 stalled workbenches, storage cabinets, drawers, 

 shelves, tables, and sinks. Workbenclies slioulcl 

 be of the proper height (approximately 36 

 inches) for laboratory work. The bench tops 

 must be of acidproof composition. This may 

 be commercial laboratory bench topping or 

 heavy wood top coated with black acid- 



resistant paint. Storage cabinets and drawers 

 should be compartmented to prevent excess 

 motion of stored materials. They should be 

 equipped with adequate retaining latches to 

 prevent them from fljnng open during heavy 

 seas. Shelves are necessary over the areas on 

 the workbenches and tables where chemical 

 titrations are run. These shelves are fitted with 

 sea racks to hold the large bottles or carboys 

 of standard solutions to which the titration 

 burettes are connected. A table, or a table- 

 height (about 30 inches) portion of the work- 

 bench is necessary for titrations and other 

 analyses that the chemist must run while 

 seated. The laboratory must have one or more 

 sinks One sink must be big enough to wash 

 large pieces of glassware and small oceanog- 

 raphic instruments. The sinks should be stain- 

 less steel and must have acidproof drainboards, 

 drains, traps, pipes, seacocks, and overboard- 

 discharge outlets. They should be furnished 

 with hot and cold fresh-water taps and a salt- 

 water tap. 



It is recommended that the laboratory deck 

 be covered with acidproof paint or an acid 

 resistant plastic (vinyl) tile. 



13-4 Distilling Apparatus. — Distilled water 

 is required to carry out almost all shipboard 

 analyses of sea water samples. This is es- 

 pecially true in the preparation of standard 

 solutions for salinity and dissolved oxygen de- 

 terminations. Small ships without evaporators 

 or those with only small emergency evaporators, 

 will have to carry several carboys of distilled 

 water. Electric distilling apparatus of the 

 Barnstead type will provide sufficient distilled 

 water, using fresh water from the ship's tanks, 

 on those ships equipped with steam evaporators. 

 The still produces very pure water when prop- 

 erly operated in accordance with the instruc- 

 tions provided by the manufacturer. The 

 distillate should be collected in 1-gallon, clear 

 glass bottles which have been thoroughly washed 

 and then rinsed with distilled water. It must 

 be remembered that a single drop of salt water 

 will contaminate a whole bottle of distilled 



H. O. 607 



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