摘要
针对浓度荧光测量时峰值法和积分法的选择问题,在理论和实验两方面对两种方法进行比较。首先理论分析峰值法和积分法的浓度测量原理;其次利用FS920型稳态荧光光谱仪扫描纯水、柴油与其混合液样品的三维荧光光谱,根据最强荧光峰确定样品的最佳激发波长为290 nm;再次根据最佳激发波长扫描浓度较低的5种样品的二维荧光光谱,由平均光谱确定主峰和肩峰波长分别为360 nm和326 nm;然后分析比较主峰和肩峰中心扩展区间和区域内积分荧光法校正模型参数的变化规律;最后,通过留一法交叉验证7种不同方法所建浓度校正模型的精度并进行比较。实验结果表明:在低浓度下,峰值和积分荧光强度与浓度之间都具有良好的线性关系,相关系数r>0.99,与理论相符;相关系数和校正决定系数随积分范围的增大先增大后减小,在峰值附近2~10 nm范围内存在极值;就积分荧光浓度模型本身而言,主峰优于肩峰,模型灵敏度、模型误差与残差平方和随积分范围的增大而增大;在浓度配置误差范围内,峰值法和积分法浓度测量绝对误差的平均值均在0.002‰以内。
For the selection problem of peak fluorescence method （PFM） and integral fluorescence method （IFM）, the comparison of two methods was implemented in two aspects of theory and experiment. Firstly, the concentration measurement principle of PFM and IFM was analyzed. Secondly, 3D fluorescence spectra of purified water, diesel and their mixed samples were scanned by FS920 steady -state fluorescence spectrometer. According to the strongest peak, the optimal excitation wavelength is 290 nm. Thirdly, 2D fluorescence spectra of 5 low concentration samples was scanned at the optimal excitation wavelength. Main peak and shoulder peak center wavelength determined from the average spectrum is 360 nm and 326 nm. And then, the IFM calibration model parameters were analyzed for the center enlarging interval and region nearby main peak and shoulder peak. Finally, the concentration calibration models based on seven different methods were crosschecked by leave-one-out method. Experiment results show that in the case of the low con-centration ,the linear relationship between the fluorescence intensity in PFM and IFM and the sample concentration is good （Correlation index r〉0.99）, which is consistent with the theory re-sults ;Correlation index and adjusted determination coefficient first increases and then decreases with enlargement of integral range, and there is an extremum at the range of 2-10 nm nearby peak center; In terms of the IFM concentration model itself, the main peak is better than the shoulder peak, and model sensitivity, error and residual sum of squares are strictly increasing with enlargement of integral range. Within the range of concentration configuration error, average of the absolute error of PFM and IFM is less than or equal to 0.002‰.
出处
《中国测试》
北大核心
2017年第12期32-40,共9页
China Measurement & Test
基金
国家自然科学基金青年科学基金(11504320)
关键词
荧光
柴油
峰值法
积分法
浓度测量
模型校正
fluorescence
diesel
peak value method
integral method
concentration measurement
model calibration
