Uncertainty of Determination of Chlorothalonil in Drinking Water by SPE-GC-MS

Objectives  To evaluate the uncertainty of determination of chlorothalonil in water by solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS).

Methods  Build mathematical model of chlorothalonil in drinking water to analyze and identify the source of uncertainty by JJF1059.1-2012 Evaluation and Expression of Uncertainty in Measurement. The uncertainty of chlorothalonil in drinking water determined by solid phase extraction-gas chromatography-mass spectrometry was assessed using law of propagation of uncertainty.

Results  The study showed that the rate of recovery (2.00%), repeated measurements (1.97%) and linear regression(1.50%)were key factors influencing the reliability of result from determination of chlorothalonil in water. The expanded uncertainty of chlorothalonil in water was 0.06 μg/L according to mathematical model established in the present study. After correction, the test result was(0.8±0.06) μg/L.

Conclusions  This method was applicable for the uncertainty evaluation of determination of chlorothalonil in water. It provided an important reference for the uncertainty evaluation for the semi volatile organic compounds determination in water.