Particulate Organic Carbon Supplement

In Reply Refer To:
Mail Stop 412                                 May 22, 2000

Office of Water Quality Technical Memorandum 2000.07

Subject:  Particulate Organic Carbon Supplement

Office of Water Quality (OWQ) Technical Memorandum 2000.05 released on
April 28, 2000, introduced the new lab and field methods for particulate
carbon and gave a list of materials that will be needed with these new
methods.  After field trials, we can now recommend an additional filtering
apparatus that is suitable to use with these methods in addition to the
Teflon DOC-25 filtration apparatus specified in the previous memo.  The
filtering apparatus designated in this memo is a vacuum flask and a filter
funnel similar to those often used for other small volume filtering
operations.  Either filtering apparatus will produce good results for
particulate organic carbon samples and the costs are roughly the same.  The
parts recommended for the vacuum filtration procedure are:

    Polypropylene filtering flask (VWR # 29417 or equivalent)
    25-mm polysulfone filter funnel w/200 ml reservoir (VWR # 28144-754 or
equivalent)
    Nalgene hand vacuum pump (VWR # 54903 or equivalent)

This vacuum filtration apparatus is not usable if you choose to capture the
filtrate for a DOC sample.  If you want to use the filtrate that passes
trough the glass fiber filters DOC analysis, DOC-25 must be used.



                    Janice R. Ward /s/
                    Acting Chief, Office of Water Quality

This memorandum is a supplement to the OWQ Technical Memorandum 2000.05.

Distribution: All WRD Employees