Environmental Testing Services

TTO Volatile Organic Compounds in Wastewater Analysis by EPA 624.1


EPA 624.1 is used to determine the concentrations of Volatile Organic Compounds (VOCs) in wastewater.


EPA 624.1 is performed by purging low-solubility VOCs from the sample, trapping those VOCs in a sorbent tube, and then desorbing the VOCs from the sorbent tube and into a capillary gas chromatography column that is interfaced to a mass spectrometer (GC/MS).

Holding Time

All samples must be analyzed within 14 days of collection. Samples not analyzed within this period must be discarded and replaced.

Container and Preservative

Collect all samples in (2) 40-mL clear glass vials fitted with fluoropolymer-lined screw caps containing 0.25 to 0.5 mL of 1+1 hydrochloric acid (HCl), attaining a pH of 2. Fill each vial in such a manner that no air bubbles pass through the sample as the bottle is being filled, and so that no air bubbles are entrapped in it after sealing (zero headspace). Ice or refrigerate samples at ≤6 °C from the time of collection until analysis, but do NOT freeze. If residual chlorine is present, add a dechlorinating agent (e.g., 80 mg/L sodium thiosulfate, ascorbic acid, or sodium sulfite) and gently mix prior to sealing the vials.

Shipping/Transport Instructions

Samples must be chilled to >0°C to ≤6 °C at collection and kept at >0 °C to ≤6 °C until analyzed. Field samples must be packaged for shipment with sufficient ice to ensure that they will be >0 °C to ≤6 °C upon arrival at the laboratory.

Analytes and Reporting

Limits Analytes routinely reported are listed below.


Analyte CAS Number Reporting Limit
Chloromethane (Methyl chloride) 74-87-3 1 µg/L
Vinyl chloride 75-01-4 1 µg/L
Bromomethane (Methyl bromide) 74-83-9 1 µg/L
Chloroethane 75-00-3 1 µg/L
Acrolein 107-02-8 5 µg/L
1,1-Dichloroethene 75-35-4 1 µg/L
Methylene chloride (DCM) 75-09-2 1 µg/L
Acrylonitrile 107-13-1 5 µg/L
trans-1,2-Dichloroethene 156-60-5 1 µg/L
1,1-Dichloroethane 75-34-3 1 µg/L
Chloroform 67-66-3 1 µg/L
1,1,1-Trichloroethane 71-55-6 1 µg/L
Carbon tetrachloride 56-23-5 1 µg/L
1,2-Dichloroethane (EDC) 107-06-2 1 µg/L
Benzene 71-43-2 1 µg/L
Trichloroethene (TCE) 79-01-6 1 µg/L
1,2-Dichloropropane 78-87-5 1 µg/L
2-Chloroethyl vinyl ether 110-75-8 1 µg/L
Bromodichloromethane 75-27-4 1 µg/L
cis-1,3-Dichloropropene 10061-01-5 1 µg/L
Toluene 108-88-3 1 µg/L
trans-1,3-Dichloropropene 10061-02-6 1 µg/L
1,1,2-Trichloroethane 79-00-5 1 µg/L
Tetrachloroethene (PCE) 127-18-4 1 µg/L
Dibromochloromethane 124-48-1 1 µg/L
Chlorobenzene 108-90-7 1 µg/L
Ethylbenzene 100-41-4 1 µg/L
Bromoform 75-25-2 1 µg/L
1,1,2,2-Tetrachloroethane 79-34-5 1 µg/L
1,3-Dichlorobenzene 541-73-1 1 µg/L
1,4-Dichlorobenzene 106-46-7 1 µg/L
1,2-Dichlorobenzene 95-50-1 1 µg/L