摘要
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。
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 environment 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 accu- racy 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 sa{ety of agricultural products.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2015年第12期3500-3504,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(31460419
31271612)
江西省重大科技项目(20143ACB21013)
大学生创新计划项目(201410410010)
江西省2014远航工程项目资助
关键词
激光诱导击穿光谱
直接检测
偏最小二乘
皮蛋壳
CU
准确度
Laser induced breakdown spectroscopy（LIBS）
Direct detection
Partial least squares（PLS）
Eggshell
Cu
Accuracy
