Determination Of Metal Ions In Water And Uncertainty Analysis

In this paper for domestic water cationic K, Na, Ca, Mg, Fe, Al, respectively for determination of chemical analysis and using icp-aes analysis, and compares the two methods of analysis of accuracy and precision. Draw many times after repeated measurement accuracy when the difference is not big, can meet the requirement analysis. In respect of precision icp-aes is much higher than that of chemical analysis method. But chemical analysis methods operation trival, EDTA titration of calcium magnesium in operation should be uniform titration; Flame photometer need to keep the air pressure in the process of measurement and the fuel pressure constant, and often use a standard solution calibration readings; Potassium thiocyanate spectrophotometry to measure iron always facing reagent. These chemical operation for the operator individual ability demand is high, poor reproducibility. Operation process is short, icp-aes determination results is more stable, low production cost, improve the production efficiency, experiment report issued a more rapid, stable and accurate.The uncertainty of hardness in the domestic water calculation, a detailed quantitative analysis, it is concluded that the selected water hardness, the final result was 216.8 + /- 1.2(mg/L). In the process of measurement, calibration of EDTA standard solution concentration and determination of influence on the repeatability of measurement results, and thus reduce the introduction of the uncertainty of calibration EDTA standard solution concentration to reduce the uncertainty of measurement results of the method is most obvious. Of icp-aes determination of water cationic Cu, Pb, zinc, Cr, Co, Ni, Fe, Mn, Al metal ions, such as the uncertainty analysis, obtained in the process of measurement, the least squares curve fitting and repeatability of measurement results for the determination of impact is bigger, so should pay attention to in the work of the working curve fitting measurement, compared with the experienced standard curve should be paid attention to.