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运用激光诱导击穿光谱(LIBS)技术对皮蛋壳中Cu元素直接进行检测,获得样本中Cu元素的特征谱线信息,采用湿法消解结合原子吸收分光光度计(AAS)测量样品中Cu元素的真实含量。由于LIBS检测的精度和准确度受到样品基体复杂,环境噪声,系统噪声,激光能量稳定性等一系列因素的影响,采用传统的单变量赛伯-罗马金拟合方式对样品的LIBS相对强度和浓度进行线性拟合不能满足定性分析的要求,因此,采用一种多变量的分析-偏最小二乘(PLS)对LIBS光谱数据进行了处理,比较分析了不同点数平滑处理和五种预处理方法对PLS建模精度和准确度的影响。分析得出采用11点平滑结合多元散射校正(MSC)预处理能有效地提高PLS建立的模型的相关系数,降低均方根误差和平均相对误差,有效提高了模型的准确性。研究结果表明,激光诱导击穿光谱技术能够准确地直接检测皮蛋壳中重金属Cu的含量,下一步的工作将对皮蛋进行批量试验,寻找出蛋壳与蛋清、蛋黄中重金属Cu的数量关系,实现通过LIBS检测皮蛋壳便可知蛋清、蛋黄中重金属含量的目标,为农产品质量安全提供新的快速无损检测技术方法。
The Cu element in shell eggshell was directly detected by laser-induced breakdown spectroscopy (LIBS), and the characteristic line information of Cu element in the sample was obtained. The content of Cu in the sample was measured by wet digestion combined with atomic absorption spectrophotometer (AAS) Real content Because the accuracy and accuracy of LIBS detection are affected by a series of factors such as complex matrix, ambient noise, system noise and laser energy stability, the LIBS relative intensity and LIBS Therefore, a kind of multivariate analysis-partial least squares (PLS) was used to process the spectral data of LIBS. The different point smoothing and five kinds of pretreatment methods were compared Impact on PLS modeling accuracy and accuracy. The results show that using 11-point smoothing and multivariate scatter correction (MSC) pretreatment can effectively improve the correlation coefficient of PLS model, reduce the root mean square error and average relative error, and improve the accuracy of the model effectively. The results show that laser-induced breakdown spectroscopy can accurately and directly detect the contents of heavy metal Cu in the preserved eggshell. The next step is to conduct a batch experiment on the preserved eggs to find out the relationship between the quantity of Cu, The detection of egg shell by LIBS can be egg whites, egg yolk in the heavy metal content of the target for the quality and safety of agricultural products to provide a new rapid non-destructive testing methods.