| 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) |
Environmental
|
| 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.
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