California Water Science Center

Organic Matter Research Laboratory


Brian Bergamaschi
Research Lead

Jacob Fleck
Lab Supervisor

Angela Hansen
Lab Manager

Amaryl Griggs
Lab Technician

Quratulain Ahmed
Lab Technician

USGS Organic Matter Research Lab

How to collect and submit a sample to the Organic Matter Research Lab

What analysis method do you need? See the Analysis Methods page for a cross-reference of lab analysis codes, detection limits, NWIS codes, and method reference publications.

Sample integrity must be maintained throughout the sampling process, from field collection to delivery of samples to the laboratory. Please refer to the USGS National Field Manual (NFM) for guidance on water sampling.

See an example of a properly completed Chain of Custody (COC) Form to help ensure accurate paperwork for your project.

1. Collect your samples

  1. Samples should be collected in either a Teflon or glass container.
  2. Containers and equipment should be washed in accordance with organic carbon cleaning instructions in USGS Field Manual 3.2.2.
  3. NEVER use methanol to clean equipment used for the collection of organic carbon.

2. Prepare your samples

Most of the equipment necessary to prepare samples is available through USGS 1Stop. See table below for item descriptions and 1Stop item numbers. Hold times are ASAP for optical and 7 days for DOC.

Item Description USGS 1Stop #
40 mL pre-combusted glass amber septum VOC bottle N1560
125 mL pre-combusted glass amber bottle Q28FLD
GFF filters, combusted, 25mm, 0.3 µm or Syringe filters, 0.45 µm Q441FLD


All samples should be filtered (0.3 um GF/F or 0.45 um syringe filter) and chilled.

  1. Use baked glass microfiber filters (0.3 micron or 0.45 micron).
  2. Using gloved hands set up filtration apparatus based on equipment manufacturer instructions.
  3. Begin filtering.
  4. Pass 100-200 mL through the filter.
  5. Use this initial filtrate to rinse the filtration unit and as a flush for the filter, discard filtrate.
  6. Continue filtration after initial flush and collect filtrate.
  7. Fill a pre-combusted glass amber bottle to the shoulder.
  8. Clearly label sample according to the USGS protocol.

Sample volumes

For DOC we require a minimum of 40mL of sample but prefer to receive at least 125mL if possible for QA, reruns etc. If concentrations are high, we can receive less as we will dilute the samples for analysis.

For optical scans, we also request a minimum of 40mL. For low level samples we would prefer at least 125mL as well to meet analytical needs.


Prior to shipment to the laboratory for analysis, store samples in a cool place at 4°C, away from sunlight to limit the effect of photodegradation, biological activity and to ensure sample integrity.

3. Ship your samples

Prepare the shipping coolers

Pack glass vials and bottles in bubble wrap or foam sleeves on ice (keep chilled at <4°C). For each cooler shipped to the lab, complete a Chain of Custody (COC) form. Sampling personnel should verify that all items listed on the form are included in the container of samples to be shipped and must note any information regarding known problems that may affect sample integrity. The completed form should then be signed and dated by the person responsible for shipping the container. Seal the COC form in a zip-type bag.

Shipping information

Inform the Organic Matter Research Laboratory that a container was shipped and indicate the method of shipment. Please ship priority overnight to attn: Angela Hansen with delivery Monday-Friday.


If you determine that any information on the COC form is incorrect after shipping or if you have any questions, contact the Lab Manager,

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Page Last Modified: Thursday, 29-Dec-2016 23:05:43 EST