Abstract：In this work, the content of copper in the shell of preserved eggs were determined directly by Laser induced breakdown spectroscopy (LIBS), and the characteristics lines of Cu was obtained. The samples of eggshell were pretreated by acid wet digestion, and the real content of Cu was obtained by atomic absorption spectrophotometer (AAS).Due to the test precision and accuracy of LIBS was influenced by a serious of factors, for example, the complex matrix effect of sample, the enviro nment noise, the system noise of the instrument, the stability of laser energy and so on. And the conventional uni-variate linear calibration curve between LIBS intensity and content of element of sample, such as by use of Schiebe G-Lomakin equation, can not meet the requirement of quantitative analysis. In account of that, a kind of multivariate calibration method is needed. In this work, the data of LIBS spectra were processed by partial least squares (PLS), the precision and accuracy of PLS model were compared by different smoothing treatment and five pretreatment methods.The result showed that the correlation coefficient and the accuracy of the PLS model were improved, and the root mean square error and the average relative error were reduced effectively by 11 point smoothing with Multiplicative scatter correction (MSC) pretreatment. The results of the study show that, heavy metal Cu in preserved egg shells can be direct detected accurately by laser induced breakdown spectroscopy, and the next step batch tests will been conducted to find out the relationship of heavy metal Cu content in the preserved egg between the eggshell, egg white and egg yolk. And the goal of the contents of heavy metals in the egg white, egg yolk can be knew through determinate the eggshell by the LIBS can be achieved, to provide new method for rapid non-destructive testing technology for quality and safety of agricultural products.
Key words：Laser induced breakdown spectroscopy(LIBS);Direct detection;Partial least squares(PLS);Eggshell;Cu;Accuracy
胡慧琴，徐雪红，刘木华，涂建平，黄 乐，黄 林，姚明印*，陈添兵，杨 平 . 激光诱导击穿光谱结合偏最小二乘法直接检测皮蛋壳中的Cu含量 [J]. 光谱学与光谱分析, 2015, 35(12): 3500-3504.
HU Hui-qin, XU Xue-hong, LIU Mu-hua, TU Jian-ping, HUANG Le, HUANG Lin, YAO Ming-yin*, CHEN Tian-bing, YANG Ping. Determination of Cu in Shell of Preserved Egg by LIBS Coupled with PLS . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2015, 35(12): 3500-3504.
