Comparison of quantification strategies for one-point standard addition calibration: The homoscedastic case

• Published in: Analytica chimica acta 2012-02, Vol.716, p.108-111
• Main Authors: Brown, Richard J.C., Gillam, Thomas P.S.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Calibration; Chemistry; Comparison; Exact sciences and technology; Extrapolation; Mass ratios; Mathematical analysis; Precision; Standard addition; Strategy
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2011.12.041

The precision characteristics of two quantification methods for one point standard addition calibration have been quantified and compared. [Display omitted] ► When using one-point standard addition calibration two quantification strategies are possible. ► This work has compared the precision characteristics of these two methods: extrapolation and use of analytical intensities. ► It has been determined that the precision ratio of the two strategies is dependent on surprisingly simple parameters. ► For conventional standard addition the relevant parameter is the sample to standard mass ratio. ► For sequential standard addition the relevant parameter is the sample to standard analyte content ratio. Two quantification strategies for one-point standard addition calibration have been compared mathematically. One strategy involved the extrapolation of measurement points to their intercept with the x-axis to determine the analyte content in the unknown sample, and the other strategy is based upon direct calculation of the analyte content in the unknown sample using the instrumental responses obtained during measurement. The cases of both conventional standard addition calibration (C-SAC) and sequential standard addition calibration (S-SAC) have been considered. The homoscedastic situation has been considered, where the absolute precision of the instrumental response is constant. It has been determined that the precision ratio of the two strategies is dependent on surprisingly simple parameters: such as the sample to standard mass ratio (for C-SAC) and the analyte content ratio (for S-SAC).