检出限是指产生一个能可靠地被检出的分析信号所需要的某物质的最小浓度或含量，包括方法检出限和仪器检出限，其中仪器检出限是仪器的检出能力，而方法检出限是前处理方法和检测方法检出能力的集合。检出限是评价检测方法检出能力的重要指标，目前有多种检出限分析方法，包括三倍噪音值法、IUPAC法、色谱计量检定法、EPA法、Hubaux-Vos法以及数学模型法等，但对于上述方法的差异，以及实际应用并不明确。本研究以超高效液相色谱-荧光检测器对桔霉素的检出限为研究对象，分析比较了上述6种仪器检出限的计算方法。结果表明，桔霉素的仪器检出限在0.009~0.344 ng/mL之间，其中，因数学模型法考虑到了标准偏差的变化，其可信度相对较高。该文通过比较分析6种常见仪器检出限的计算方法，为检出限在检测过程中的实际应用提供参考。

Detection limit is defined as the minimum concentration or content of a substance which can produce a reliable analytical signal, including the method detection limit and the instrumental detection limit. The instrumental detection limit relies only on the analysis ability of instrument, and the method detection limit is a collection of the pretreatment and detection ability of instrument. Detection limit, as one of the most important parameters of method to evaluate the detection ability, can be analyzed by different calculation methods, including 3N/S, IUPAC, HPLC, EPA, Hubaux-Vos and mathematical model. However, the difference among these methods and their application were not definite. In this study, the detection limit of citrinin using ultra-high performance liquid chromatography fluorescence detector was calculated by different methods. The results showed that the instrumental detection limit of citrinin was in the range of 0.009~0.344 ng/mL. The mathematical model was reliable due to the considered variation of standard deviation. In conclusion, the comparison of characteristics of calculation methods in chromatography can provide a reference for practical application of detection limit in detection process.

国家自然科学基金面上项目（31371824）；湖北省农业科学院竞争性计划项目（2016JZXJH01）