Recovery tests of 25 volatile organic compounds (VOCs) spiked into drinking water were performed under various test conditions to evaluate the effects of cooling experimental apparatuses and solvents and diluting water samples during preparation of calibration standard solutions and water samples on analytical precision for testing the VOCs in drinking water using a purge and trap-gas chromatography/mass spectrometry (PT-GC/MS). As a result, compounds with small Henry's constants (i.e., compounds with high volatility) were more affected in trueness and repeatability when cooling was not applied during the test operations. In addition, when the water sample was diluted, the trueness and repeatability was decreased even if cooling was applied during the test operations. Therefore, it is important to conduct test operations with cooling experimental apparatuses and solvents, and without diluting the sample water to obtain better analytical accuracy in VOC analysis of drinking water samples using PT-GC/MS.
