Fry C H, Hall S K, Blatter L A, McGuigan J A
Department of Physiology, United Medical School, London.
Exp Physiol. 1990 Mar;75(2):187-98. doi: 10.1113/expphysiol.1990.sp003393.
We have considered the manner in which data obtained with ion-selective electrodes should be evaluated. The potential difference recorded by such electrodes, with respect to a stable reference, is converted to a concentration by a non-linear transformation--the Nernst or Nikolsky equation. The mean and standard deviation of such estimations of concentration are then usually presented, which assumes that the latter variable is normally distributed. If, however, the recorded potential difference (PD) is the normally distributed variable and the mean value calculated, then a different value of mean concentration will be obtained. We show here that the recorded PD is indeed the normally distributed variable using data from a variety of ion-selective electrode measurements and conclude that the mean values of quoted ion concentrations have been overestimated by 6-43%.
我们已经考虑了用离子选择电极获得的数据应如何评估。相对于稳定的参比电极，此类电极记录的电位差通过非线性变换——能斯特或尼科尔斯基方程转换为浓度。然后通常会给出此类浓度估计值的均值和标准差，这假定后一个变量呈正态分布。然而，如果记录的电位差（PD）是呈正态分布的变量并计算其均值，那么将得到不同的平均浓度值。我们在此利用来自各种离子选择电极测量的数据表明，记录的PD确实是呈正态分布的变量，并得出结论：所引用的离子浓度均值被高估了6% - 43%。
