3, 1, 1, 1, ,1,2

Study on the Physical Meaning and Determination Method of "Detection Limit" in Analytical Chemistry

3, 1, 1, 1, ,1,2

 基金资助: 国家自然科学基金面上项目.  21575129

 Fund supported: 国家自然科学基金面上项目.  21575129

Abstract

In this paper, we studied the physical meaning, measurement methods and potential problems of detection limit in analytical chemistry. The limitation of classical detection limit was also discussed. We studied the detection of thrombin by fluorescence quenching of Pt nanoparticles, based on the specific binding of thrombin aptamer to thrombin. We found a negative correlation between the measured signal and the logarithm of the concentration. In addition, the similar negative correlation was found in the determination of glucose by a glassy carbon electrode biosensor, based on CuGeO3 nanowires and glucose oxidase. The detection limit of the above two method conflicted with the classical detection limits. It appeared abnormal that the better the determination precision, the worse the detection limit.

Keywords： Detection limit ; Physical meaning ; Determination

YANG Chun, ZHENG Shan, LIU Yang, SHI Yaying, HUANG Chaobiao. Study on the Physical Meaning and Determination Method of "Detection Limit" in Analytical Chemistry. University Chemistry[J], 2018, 33(5): 51-55 doi:10.3866/PKU.DXHX201801012

1 经典分析方法的检出限的物理意义及测定方法

1.1.1 检出限的物理意义

IUPAC规定：当EISE-lnα符合图1所示的关系曲线时，则延长曲线弯曲前后的直线部分之交点所对应的被测离子的活度(由于测定过程中控制被测溶液与标准溶液的离子强度一致，可直接视为浓度)，即为该离子选择性电极的检出限。

图1

EISE-lnα符合图2所示的关系曲线，则当校正曲线偏离线性关系$\frac{18}{n}\text{mV}$时所对应的被测离子浓度即为检出限。

图2

1.1.2 检出限的测定

1.2.1 检出限的物理意义

1975年，IUPAC规定[1]：原子吸收光谱分析的检出限为当吸光度为试剂空白(噪音)的标准偏差的3倍时所对应的被测离子的浓度或质量。

参考文献 原文顺序 文献年度倒序 文中引用次数倒序 被引期刊影响因子

IUPAC Pure and Applied Chemistry 1976, 45, 107.

IUPAC. Compendium of Analytical Nomenclature.分析术语纲要, 1998.

Zhang W. ; Shi Y. ; Zheng S. ; Liu Y. ; Huang C. J. Electroanal. Chem. 2017, 784, 85.

Yong P. ; Li H. ; Xiang F. ; Li Z. Russ. J. Electrochem. 2013, 49, 642.

/

 〈 〉