分光光度法测定水体叶绿素a含量的测量不确定度分析

The evaluation of uncertainty in measuring chlorophyll a with spectrometry

采用分光光度法测定湖泊、水库水体中叶绿素a含量,评定其测量不确定度.根据水体中藻类数量的多寡,按1L和0.1L2个采样量采样.影响水体叶绿素a测量不确定度的因素包括分析取样量、样品前处理、仪器吸光度读数、玻璃量具、比色皿光程等.按照测量不确定度的传播规律建立数学模式,通过对各标准不确定度分量分析计算,求出合成不确定度(uc)和扩展不确定度(U).结果表明,样品量在1L和0.1L时,U分别为0.214mg/m3和2.32mg/m3.

Using spectrometry to measure chlorophyll a of lake, reservoir, and evaluating its uncertainty. According to alga amount of water, we choosed 2 sample volume (1 L and 0.1 L). Impacting factors of measuring uncertainty include: the amount of the sample water,the samples handling before analysis, the reading of spectrometry, glass utensils and the thickness of colorimeter. Based on uncertainty regulations to establish the mathematics mode and calculate each standard uncertainty, we got combined standard uncertainty (uc) and expanded uncertainty (U). Results of U were: 0.214 mg/m3 (1 L of sample volume),2.32 mg/m3 ( 0.1 L of sample volume).