Uncertainty Evaluation of Measurement Results for the Determination of HCH in Groundwater Samples by Gas Chromatography

Based on , the measurement results of HCH in groundwater samples by gas chromatography （GC） were collected and the measurement uncertainty was evaluated. The sources of uncertainty produced in analysis process were discussed and the sampling volume for HCH extraction, volume fixing for HCHextracted sample solution, sample volume introduced in GC instrument, measurement of the calibration standard solutions and the repetitive measurements of the instrument, etc. were considered as the main sources of the measurement uncertainty. The uncertainty expression parameters and mathematical models for calculating each parameter were also proposed. And the expanded uncertainty was obtained from synthesize standard uncertainty multiplied by expanded factor of 2 under the confidence level of 95%.