Pardue H L
Department of Chemistry, Purdue University, West Lafayette, IN 47907-1393, USA.
Clin Chem. 1997 Oct;43(10):1831-7.
The formal definition of sensitivity associates the term with the change in the response of a system for a small change of the stimulus causing the response, i.e., the ratio of the response of a system to the stimulus causing it. One interpretation of sensitivity associates the rate of change of the response for a small change of the stimulus as the slope of a calibration plot of response vs stimulus. An alternative interpretation associates sensitivity with the smallest value of the stimulus that can be resolved with a given degree of confidence, i.e., the detection limit. Applications of the first usage to analytical chemistry date at least to the beginning of this century; applications of the second interpretation are of more recent origin. The accompanying paper argues in favor of the second interpretation on the basis that, among other things, the "slope" interpretation conflicts with the formal definition of sensitivity and is meaningless as a descriptor of the performance of a measuring system. In this paper I offer arguments to support my belief that the slope definition of sensitivity is consistent with both formal definitions and accepted usage in analytical chemistry and, more importantly, that it is an invaluable descriptor of one of the most important characteristics of any analytical method. I include information to support my belief that proper use of the slope definition yields much more information than is available in the "detection limit" interpretation.
灵敏度的形式定义将该术语与系统响应随引起响应的刺激的微小变化而发生的变化相关联，即系统响应与引起该响应的刺激的比率。对灵敏度的一种解释是，将响应随刺激的微小变化的变化率视为响应与刺激校准图的斜率。另一种解释是将灵敏度与在给定置信度下能够分辨的最小刺激值相关联，即检测限。第一种用法在分析化学中的应用至少可以追溯到本世纪初；第二种解释的应用则是较新的起源。随附的论文支持第二种解释，理由之一是，“斜率”解释与灵敏度的形式定义相冲突，并且作为测量系统性能的描述符毫无意义。在本文中，我提出论据来支持我的观点，即灵敏度的斜率定义与分析化学中的形式定义和公认用法均一致，更重要的是，它是任何分析方法最重要特征之一的宝贵描述符。我还提供信息来支持我的观点，即正确使用斜率定义所产生的信息比“检测限”解释中可得的信息要多得多。
