Coordinate Swapping in Standard Addition Graphs for Analytical Chemistry: A Simplified Path for Uncertainty Calculation in Linear and Nonlinear Plots

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• 作者：Juris Meija ; Enea Pagliano ; Zolt谩n Mester
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：September 2, 2014
• 年：2014
• 卷：86
• 期：17
• 页码：8563-8567
• 全文大小：207K
• ISSN：1520-6882

文摘

Uncertainty of the result from the method of standard addition is often underestimated due to neglect of the covariance between the intercept and the slope. In order to simplify the data analysis from standard addition experiments, we propose x鈥?i>y coordinate swapping in conventional linear regression. Unlike the ratio of the intercept and slope, which is the result of the traditional method of standard addition, the result of the inverse standard addition is obtained directly from the intercept of the swapped calibration line. Consequently, the uncertainty evaluation becomes markedly simpler. The method is also applicable to nonlinear curves, such as the quadratic model, without incurring any additional complexity.