• 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)).

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

• 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.

• 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. 

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.