The determination of the rodenticide tetramethylenedisulfotetramine (TETS) in drinking water is reportable through the use of automated sample preparation via solid phase extraction and detection using isotope dilution gas chromatography-mass spectrometry. The method was characterized over twenty-two analytical batches with quality control samples. Accuracies for low and high concentration quality control pools were 100 and 101%, respectively. The minimum reporting level (MRL) for TETS in this method is 0.50 μg L−1. Five drinking waters representing a range of water quality parameters and disinfection practices were fortified with TETS at ten times the MRL and analyzed over a 28 day period to determine the stability of TETS in these waters. The amount of TETS measured in these samples averaged 100 ± 6% of the amount fortified suggesting that tap water samples may be held for up to 28 days prior to analysis.
