Chlorophenoxy herbicides – Drinking Water

Laboratory Fee Schedule
Procedure #:  EZZ0079A 



Chlorophenoxy acid herbicides in Water

Requisition Form


Test Description

Chlorophenoxy herbicides, EPA method 515.4

Pre-Approval Needed


Supplemental Information Required


Supplemental Form(s)


Performed on Specimens from (sources)


Sample/Specimen Type for Testing

Drinking Water

Minimum Volume/Size Required

Two amber glass bottle with Teflon (PTFE) cap liner; 40 mL

Storage/Preservation Prior to Shipping

  • Add 2 mg of sodium sulfite (Na2SO3) to the empty container (to dechlorinate).
  • Open the tap and allow the system to flush until the water temperature stabilizes, at least 5 minutes. 
  • When sampling from a water tap, remove the aerator so that no bubbles will be trapped in the sample. Turn flow down to a smooth, pencil thin stream.
  • Remove cap from the bottle, tilt, and place under stream. 
  • Fill the container with water taking care not to flush out the sodium sulfite and seal. 
  • Mix by repeatedly inverting for 15 seconds. DO NOT SHAKE.
  • Duplicates are required; collect one duplicate for every ten samples.
  • Store at <10°C. DO NOT FREEZE.
  • Store samples in the dark.

Transport Medium


Specimen Labeling

  • Label each bottle with a waterproof marker.
  • Pre-printing labels is acceptable.  
  • Sample identification must match submission form.

Shipping and Specimen Handling Requirements

  • Ship according to Dangerous Goods Regulations, IATA, and/or CFR 49.
  • Store at <10°C. DO NOT FREEZE.
  • Store samples in the dark.


EPA 515.4

Turn-around Time

Samples must be extracted by the lab within 14 days of collection.


Matrix interferences may be caused by contaminants that are coextracted from the sample. The extent of matrix interferences may vary considerably from sample to sample. Interferences by phthalate esters can pose a major problem in pesticide analysis when using an electron capture detector (ECD). These compounds generally appear in the chromatogram as large peaks. Common flexible plastics contain varying amounts of

phthalates that are easily extracted or leached during laboratory operations.

Common Causes for Rejection

Insufficient quantity, unacceptable specimen type or source, improper shipping conditions, expired media or collection container, discrepancies between specimen label and submission form, and/or incomplete or missing submission form

Additional Information

Contact the laboratory at (512) 776-7587 for currently supported analyte list.