| Synonym(s): |
Semivolatiles in Water |
| Requisition Form |
G-22 |
| Test Description |
Semi-volatile organic compounds by GC-MS, EPA method 525.2 |
| Pre-Approval Needed |
N/A |
| Supplemental Information Required |
N/A |
| Supplemental Form(s) |
N/A |
| Performed on Specimens from (sources) |
Environmental |
| Sample/Specimen Type for Testing |
Drinking Water |
| Minimum Volume/Size Required |
Narrow-mouth (or wide mouth) amber glass with Teflon (PTFE) cap liner; 1 quart (1 L) |
| Storage/Preservation Prior to Shipping |
- Add 50 mg of sodium sulfite (Na2SO3) to the empty container (dechlorinating agent)
- 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.
- Sampling equipment must be free of plastic tubing, gaskets or other parts that may leach interfering analytes into the sample.
- Fill half the container with sample water. Mix gently until sodium sulfite is completely dissolved.
- Add 3 to 4 mL 6N HCl in order to achieve a pH of < 2. (HCl is used as a preservative)
- Finish filling the container (to shoulder) and seal. A small amount of head space is acceptable.
- Mix for one minute.
- Store samples in the dark from time of collection until extraction (Iced (4°C)).
|
| Transport Medium |
N/A |
| Specimen Labeling |
- Label each bottle with a water proof 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).
- Store samples in the dark from time of collection until extraction.
|
| Method |
EPA 525.2 |
| Turn-around Time |
Samples must be extracted by the lab within 14 days of collection. |
| Interferences/Limitations |
- Be careful not to add too much Na2SO3to the sample because this may cause interference in the analysis
- Sampling equipment must be free of plastic tubing, gaskets or other parts that may leach interfering analytes into the sample.
- 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.
- Organic acids in field samples will co-elute with the target compounds. The organic acids spectra will affect the target compound spectral purity.
- Some polycyclic aromatic hydrocarbons (PAH), including the labeled PAHs used in this method as internal standards, are rapidly oxidized and / or chlorinated in water containing residual chlorine.
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| 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 |
1) Laboratory QC duplicates are required for samples. One in ten samples should be collected in triplicate. For the sample to be triplicated, add the words “+DUP” The sample and duplicates will be submitted with the one analysis form.
2) 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 10 mg of Na2SO3.
- For example: a sample with 7 mg/L chlorine would require 70 mg of Na2SO3.
- Be careful not to add too much Na2SO3 to the sample because this may cause interference in the analysis.
3) If you must collect a sample for prometon, you will NOT add the acid.
Make sure that the submission form is labeled well stating “PROMETON, NO ACID”.
Contact the laboratory at (512) 776-7587 for currently supported analyte list.
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