Water Quality--Preservation and Shipment of Water Samples for the Determination of Mercury. 
 

In Reply Refer To:                           September 28, 1984
WGS-Mail Stop 412



QUALITY OF WATER BRANCH TECHNICAL MEMORANDUM 84.18 

Subject:  Water Quality--Preservation and Shipment of Water 
          Samples for the Determination of Mercury. 

Effective October 1, 1984, all water samples for the determination 
of mercury must be contained in 250 mL acid-rinsed glass bottles 
with polyseal-lined caps and be preserved by the addition of 
1 ampoule of nitric acid/potassium dichromate solution.  To 
accomodate the volume of the preservative, the sample volume 
should not exceed about 200 mL.  The preserved sample in its glass 
bottle should be placed in the poly-foam sleeve provided with each 
container, the sleeve should be taped closed with nylon strap 
tape, and the sample placed in double, sealed, polyethylene bags.  
The bagged sample should be packed and shipped in a water-tight 
cooler.  Samples for mercury determination do not require 
chilling, but they may be shipped in the same cooler with chilled 
samples. 

Standard sample volumes of 200 mL will have a preservative 
concentration equivalent to 5 percent nitric acid and 0.05 percent 
potassium dichromate.  Samples will have a distinct yellow color 
and should be designated either FAM or RAM corresponding to 
filtered or whole-water samples. 

In his memorandum of September 10, 1984, to Regional Hydrologists, 
Regional Research Hydrologists, District Chiefs, and Project 
Offices, the Analytical Services Coordinator announced 
availability of ampouled nitric acid/potassium dichromate solution 
and acid-rinsed glass bottles for preserving and containing water 
samples for the determination of mercury.  Bottles and ampoules 
will be made available in units of 25, free of charge, upon 
request to the Central Laboratories.  Due to limited supply, 
Districts are urged to limit their requests to reasonable 
projected needs for not more than 6 months in advance. 

The logical basis for using an oxidizing agent in conjunction with 
a strong acid to preserve water samples for the determination of 
mercury was discussed in the Briefing Paper, "Mercury: Sampling 
Constraints and Health Considerations," transmitted by Quality of 
Water Branch Technical Memorandum 84.04, November 30, 1983. 

If there are further questions concerning preservation and 
shipment of water samples for mercury determination, please 
contact Herman Feltz at FTS 928-6834. 




                                 David A. Rickert 

WRD Distribution:  A, B, FO, PO 

This memorandum supplements Quality of Water Branch Technical 
Memorandum 84.16.