利用单光束光声光谱实验装置,分别测量了葡萄糖溶液、蔗糖溶液和蜂蜜溶液在可见光波段的光声光谱,并与分光光度法测得的数据进行了比较。上述溶液的光谱特征表明:不同种类的溶液,光谱背景强度和轮廓有明显差异。三种溶液的光谱在485和655nm处都有较强峰,但二者的强度比在不同溶液中有一定差异。另外,葡萄糖还在475,576和630nm处有特征峰;蔗糖在632nm处出现明显特征峰;这些光谱特征为鉴别天然蜂蜜中是否有葡萄糖或蔗糖掺假提供了依据。比较同种溶液的两种光谱发现:光声信号强度随波长的变化更灵敏,说明在物质成分检测中,光声光谱法具有更高的灵敏度。
The photoacoustic spectrum of glucose,sucrose and honey solutions in the visible range are measured by using the single-light photoacoustic spectrometer,and are compared with the spectra from spectrophotometry method.The spectral characteristics of the above solutions show that the spectral background intensity and spectral profile have some differences for different kinds of solutions.The spectra of the three kinds of solutions all have strong peak value at 485 and 655nm,but the intensity ratios between the two peaks are different.Besides,there are characteristic peak at 475,576 and 630nm for glucose,and the sucrose has apparent characteristic peak at 632 nm,these characteristic peaks can be used for detecting whether the natural honey has been added glucose or sucrose.By comparing two kinds of spectrum of the same solution,the intensity of photoacoustic spectrum is more responsive to the wavelength,indicating photoacoustic spectrometry has a higher sensitivity in the test of material composition.