VOCs Drinking Water

Laboratory Fee Schedule

Procedure: EZZ0085A



Synonym(s): VOCs in Water
Requisition Form G-22
Test Description Volatile organic compounds VOCs by GC-MS, EPA method 524.2
Pre-Approval Needed N/A
Supplemental Information Required Measure and record the chlorine residual.  If the chlorine residual is >5 mg/L, additional dechlorinating agent is required. For every mg/L of chlorine above the initial 5 mg/L add an additional 5 mg of ascorbic acid. For example: a sample with 7 mg/L chlorine would require 35 mg (25 + 5 + 5) of ascorbic acid. Be careful not to add too much dechlorinating agent to the sample because this may cause interference in the analysis.
Supplemental Form(s) N/A
Performed on Specimens from (sources)


Sample/Specimen Type for Testing Drinking Water 
Minimum Volume/Size Required Collect two vials of drinking water and two vials of reagent water for a field blank with every sample. 
Glass screw-top vial equipped with a Teflon (PTFE) faced silicone septum; 40 mL  
Storage/Preservation Prior to Shipping
  • Affix pre-printed sample labels to vials. DO NOT write on labels until after all samples are collected and vials are sealed.
  • Add 25 mg of ascorbic acid to an empty vial (to dechlorinate). 
  • Adding HCl to sample vials prior to sample collection is NOT permitted.
  • Open the tap and allow the system to flush until the water temperature stabilizes, at least 5 minutes. Turn flow down to a smooth, pencil thin stream.
  • Remove cap from the bottle, tilt, and place under stream.
  • Fill the vial half full. DO NOT SHAKE.
  • Next, add sufficient 6N HCl in order to achieve a pH of < 2. (HCl is used as a preservative) (Don’t measure the pH in the sample bottle! Verify the amount of preservative to achieve proper pH for each sample in a separate container.)
  • Complete filling the vial and seal.
  • Mix for one minute. Invert the bottle repeatedly but DO NOT SHAKE.
  • Invert the container and verify that no bubbles are present.  
  • Store samples away from any organic solvent vapors and avoid direct sunlight or intense light.
Transport Medium N/A
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.
  • Ship on ice (4°C).
Method EPA 524.2
Turn-around Time Samples must be analyzed by the lab within 14 days of collection.
Interferences/Limitations Avoid collecting this type of sample in any situation where you can smell petroleum or solvent type fumes.
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

Collecting Field Blanks:

  • A field blank consisting of two vials is required when collecting all VOC samples to rule out air contamination. Treat the field blank in the same manner as the water sample.
  • The field blank is collected at the same location and time that the water sample is collected.
  • Label the containers to indicate that it is a field blank (“FB” or “Field Blank”).
  • Add ascorbic acid to each empty vial.
  • Add laboratory grade reagent water instead of sample water. Once the container of laboratory reagent water is opened for this field blank, it can’t be used again.
  • Add HCl to a pH <2.
  • Complete filling the vials and seal.
  • Mix for one minute. Invert the bottle repeatedly, do not shake.

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