Department of Analytical Chemistry, University of Granada, Granada, Spain.
Anal Bioanal Chem. 2011 Nov;401(9):2881-9. doi: 10.1007/s00216-011-5366-8. Epub 2011 Sep 6.
An approach based on IUPAC methodology to estimate the limit of detection of bulk optode-based analytical methods for anions has been developed. The traditional IUPAC methodology for calculating the detection limit was modified to be adapted to particular cases where the calibration curves have a sigmoidal profile. Starting from the different full theoretical models for every co-extraction mechanism of the analyte in the membrane in bulk optodes, several particular simplified models at low analyte concentration were obtained and validated. The slope of the calibration curve at low analyte concentration was calculated from the first derivative of the simplified equation and, subsequently, the detection limit was estimated. This fitted-for-purpose estimation strategy was applied to anion quantification for in-house bulk optode-based analytical methods, and the estimated limits of detection were compared with those obtained by applying classical geometrical methodology. This way of establishing the detection limit yields values that maintain their true statistical and probabilistic aspects. It can be easily applied to any analytical system which yields non-linear calibration curves at low analyte concentration.
已经开发出一种基于 IUPAC 方法的方法来估计基于 bulk optode 的阴离子分析方法的检测限。对传统的 IUPAC 检测限计算方法进行了修改，以适应校准曲线具有 S 形轮廓的特殊情况。从 bulk optode 中膜中分析物的每种共萃取机制的不同全理论模型出发，获得并验证了几个在低分析物浓度下的简化模型。从简化方程的一阶导数计算低分析物浓度下校准曲线的斜率，然后估算检测限。该特定用途的拟合估计策略应用于基于 bulk optode 的内部分析方法对阴离子的定量，并且将估计的检测限与通过应用经典几何方法获得的检测限进行了比较。这种建立检测限的方法产生的结果保持了其真实的统计和概率方面。它可以很容易地应用于任何在低分析物浓度下产生非线性校准曲线的分析系统。
