ClPestdw

Synonym(s):

Chlorinated pesticides and PCBs in Water

Requisition Form

G-22

Test Description

Chlorinated pesticides and polychlorinated biphenyls (PCBs) in drinking water, EPA method 508.1

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.
• Fill half the container with sample water. Mix gently until sodium sulfite is completely dissolved.
• Add 3 to 4 mL 6N hydrochloric acid (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
• Store at 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 508.1

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.

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, 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 only 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.

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