激光击穿光谱检测葡萄糖溶液的实验研究

利用Nd∶YAG脉冲激光器波长为1.064μm的光束诱导葡萄糖溶液产生等离子体,并用光谱仪和ICCD来探测其光谱信号。选取碳(C:247.86 nm)作为葡萄糖的特征谱线,比较浓度为3%,6%,9%的葡萄糖溶液谱线强度的大小,得出谱线强度随浓度增大而增强的规律。在同一浓度下,通过改变ICCD延时采样的时间,获得特征谱线的强度演化曲线,实验结果表明,特征谱线的衰减时间约为300 ns。改变溶液浓度,发现特征谱线的衰减过程不受溶液浓度的影响。

Experimental Study on Glucose Solution by Laser-Induced Breakdown Spectroscopy

The glucose solution was broken down by focusing the 1.064 microm beam of a Nd : YAG laser, and the plasma was produced. The spectral signals were detected by an experimental setup including spectrograph and ICCD. The spectral line at 247.86 nm was identified as the characteristic of glucose by contrasting the spectra of glucose solution and pure water. Comparing the spectral intensities of three kinds of glucose solution with different concentrations (3%, 6% and 9%), the experimental result showed that the bigger the concentration, the stronger the spectral intensity,and the characteristic spectral intensities with the three concentrations present the trend of logarithm increase. At the same concentration, the time evolution curve of the characteristic spectra was obtained by changing the delay time of ICCD. It is concluded that the intensity of the characteristic spectra first increases and then decreases with the delay time. With the glucose solution concentration altering, the decay time of the characteristic spectra is nearly fixed, meaning that the decay time is independent of the concentration. The decay time of the characteristic spectra is about 300 ns. Furthermore, it was found that the characteristic spectral intensities of glucose solution with different concentrations reach the maximum at the same delay time.