FIELD TECHNIQUES--Field Preparation of Containers for Aqueous Samples



In Reply Refer To:                            December 20, 1991
Mail Stop 412


OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM 92.02

Subject:  FIELD TECHNIQUES--Field Preparation of Containers 
                            for Aqueous Samples

The purpose of this memorandum is to provide standard operating 
procedures for field rinsing and use of sample containers.  

Please note that the Office of Water Quality (OWQ) and the 
National Water Quality Laboratory (NWQL) are conducting studies to 
determine causes of observed contamination of trace-element 
samples (refer to OWQ Technical Memorandum 91.10).  The results of 
these studies may require modifications of field procedures, 
including preparation of sample containers.  Until the need for 
new procedures is documented, the following protocols should be 
adhered to for routine field rinsing of containers used for 
aqueous sample solutions.


              CONTAINERS FOR INORGANIC CONSTITUENTS
         (including major, minor, and trace elements, and
             isotopes of carbon, nitrogen, and sulfur)

PROTOCOLS
1.   All containers and their caps are to be rinsed at the field 
     site immediately prior to sample collection with the sample 
     solution that will be analyzed from that container.

     A.   Use deionized water for blank samples.

     B.   Use filtered sample solution to rinse containers 
          designated:
          o  filtered/acidified (FA, FAM, FAB),
          o  filtered/untreated (FU), 
          o  filtered/chilled (FC).

     C.   Use unfiltered sample solution to rinse containers 
          designated:
          o  raw/acidified (RA, RAM, RAB),
          o  raw/untreated (RU), 
          o  raw/chilled (RC).

2.   Teflon bottles or acid-rinsed polyethylene bottles that are 
     received uncapped from the laboratory are NOT to be used
     (field rinsing is not an acceptable method of cleaning Teflon 
     or acid-rinsed polyethylene bottles).  

     A.   Uncapped acid-rinsed polyethylene bottles are to be 
          discarded.

     B.   Uncapped Teflon bottles should be returned to the 
          laboratory.


EXCEPTIONS TO PROTOCOLS FOR INORGANIC CONSTITUENTS
     (for situations that are not clear cut or not covered 
     by this memorandum, project personnel should consult 
     with their Regional Water-Quality Specialist)

1.   Sample containers for tritium, hydrogen, or oxygen isotope 
     analysis are NOT to be prerinsed.  (Although not specifically 
     related to container preparation, please note that polyseal 
     caps--caps with conical plastic inserts--are required for 
     tritium, hydrogen, and oxygen bottles.

2.   Containers supplied by a cooperator or laboratory other
     than the NWQL MAY NOT REQUIRE field rinsing.  These 
     containers may have been specially precleaned and(or) contain 
     sample preservative.  Field personnel should follow the 
     supplier's instructions.  

3.   Rinsing sample containers with deionized (DI) water instead 
     of sample solution may be necessary or desirable under 
     certain field conditions, provided that the deionized water 
     is of a known quality that, at a minimum, conforms to the 
     standards and guidelines specified in OWQ Technical 
     Memorandum 92.01.  Cases for which a DI water rinse may be 
     appropriate:

    A.   Quantity of sample is low.  Sources for which sample 
         volume may be inadequate include:  unsaturated-zone 
         water, ground water from wells completed in low-yielding 
         sediments, or atmospheric deposition.  

         Calculations based upon data in Appendix II, 
         OWQ Technical Memorandum 92.01, indicate that sample 
         dilution from residue DI rinsate would be insignificant.

    B.   Potential exists for a positively biased analysis owing 
         to sorption of sediments to container walls during a 
         rinse with environmental sample solution (that contains 
         high concentrations of suspended materials) with 
         subsequent desorption following acidification.  

         The OWQ currently has no data that confirm or disprove 
         the possibility that analyte sorption produces 
         measurable positive or negative biases.  Studies that 
         the OWQ has planned eventually should provide more 
         definitive guidance.  Project chiefs are responsible to 
         use professional judgement and implement quality-control 
         procedures that are appropriate to ensure the level of 
         data accuracy required for their project.


                  CONTAINERS FOR ORGANIC COMPOUNDS

PROTOCOLS

1.   For organic compounds, do NOT rinse sample containers 
     provided by the NWQL.  These containers have been prepared 
     according to strict procedures appropriate for the designated 
     analysis and should be filled directly with sample solution.  

2.   Do NOT use bottles received from the laboratory for organic 
     analyses that are uncapped.  

     A.  Uncapped bottles should be discarded or returned to the 
         laboratory.

EXCEPTIONS TO PROTOCOLS FOR ORGANIC COMPOUNDS

     None.



                               David A. Rickert
                               Chief, Office of Water Quality

Key words:  field rinsing, bottle/container rinse, field 
            techniques, deionized water, inorganic elements, 
            isotopes, organic compounds.

This memorandum does not supersede any previous Office of Water 
Quality Technical Memorandum. 

Distribution: A, B, S, FO, PO