Evaluation on Uncertainty of Determining Magnesium in Drinking Water by Flame Atomic Absorption Spectrophotometry

Objectives According to the content of magnesium in drinking water with flame atomic absorption spectrophotometry, analyze and assess factors influencing the uncertainty in testing process.

Methods Based on the theory of evaluating uncertainty, the sources of uncertainty in whole testing process were analyzed and calculated.

Results The main sources of uncertainty were from developing standard solution (including the preparation of standard stock solution, and the dilution of standard solution) and standard curve fitting, the degree of sample dilution and preparation and repeated sample measurements.

Conclusions The test results of magnesium in drinking water were C_Mg=(0.395±0.012) mg/L, k=2 (confidence level≈95%).