分光光度法快速测定玉米叶片中的叶绿素

Spectrophotometric Determination of Chlorophyll Concentrations in Maize Leaves

以玉米叶片为材料,利用双波长双光束紫外可见分光光度计,用最大决定系数增量回归算法,研究了叶片叶绿素a、b及SPAD值同时、快速测量方法。结果表明,用3个波长点建立的模型可以达到良好的预测效果,预测叶绿素a、b及SPAD值的相关系数分别为0.9919、0.9816和0.9757;标准差分别为1.52、0.43和1.96;预测相对标准差分别为4.64%、5.50%和4.88%。同时研究了仪器波长误差和带宽变化对测定结果的影响,发现波长偏移超过0.2nm,误差快速增大,且波长向长波方向偏移时对测量的影响要大于向短波方向偏移的影响;仪器带宽变大,预测误差也就越大。

Based on double-wavelength/double-beam ultraviolet-visible spectrophotometry and MAXR （maximum R2 improvement） regression procedure, a method for rapidly and synchronously determining the concentrations of chlorophyll a, chlorophyll b and the value of soil and plant analytzer development （SPAD） in maize leaves was introduced. By establishing the quantitative analysis model which includes three wavelengths information, the satisfactory results were obtained. With this model to predict the contents of above 3 components of unknown maize samples, the correlation coefficients of prediction are 0. 9919,0. 9816 and 0. 9757; the standard errors of prediction are 1.52, 0.43 and 1.96 ; the relative standard errors of prediction are 4. 6%, 5.5% and 4.9% respectively. The results of the model to predict the contents of above 3 components were changed with the shift of wavelength and the variety of bandwidth of spectrophotometer. The relative standard errors of prediction are changed worse quickly when the shift of wavelength was more than 0.2 nm and the results by the positive shift of wavelength were worse than by the negative shift of wavelength, and the results would be worse as broaden or narrow of bandwidth in spectrophotometer.