塑料标准样品结合偏最小二乘法在激光诱导击穿光谱法元素定量分析领域的研究  

Plastic Reference Material(PRM)Combined With Partial Least Square(PLS)in Laser-Induced Breakdown Spectroscopy(LIBS)in the Field of Quantitative Elemental Analysis

作　　者：王斌[1,2] 郑少锋 甘久林 刘曙[3] 李伟才 杨中民 宋武元[4] WANG Bin;ZHENG Shao-feng;GAN Jiu-lin;LIU Shu;LI Wei-cai;YANG Zhong-min;SONG Wu-yuan(State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,Guangzhou 510641,China;State Key Testing Laboratory of Consumer Products,Huangpu Customs Technology Center,Dongguan 523070,China;Technical Center for Industrial Product and Raw Materical Inspection and Testing,Shanghai Customs,Shanghai 200135,China;Guangzhou Customs District Technology Center,Guangzhou 510623,China)

机构地区：[1]华南理工大学,发光材料与器件国家重点实验室,广东广州510641 [2]黄埔海关技术中心,国家消费品安全检测重点实验室,广东东莞523070 [3]上海海关工业品与原材料检测技术中心,上海200135 [4]广州海关技术中心,广东广州510623

出　　处：《光谱学与光谱分析》2023年第7期2124-2131,共8页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2018YFF0215400);国家标准样品研复制计划项目(S2017055)资助。

摘　　要：激光诱导击穿光谱法以其快速、高效、无害、全谱直读、几乎不需要样品制备等优势,广泛用于元素定量分析领域,为了建立简单易行的分析方法,利用自行研制的聚丙烯塑料(PP)标准样品(RM),结合偏最小二乘法(PLS),运用激光诱导击穿光谱方法(LIBS),建立了Pb和Cr元素的PRM-PLS-LIBS分析模型。PP标准样品是按照国际标准要求进行研制,Pb和Cr的含量梯度根据各个国家和地区的限制要求,设定范围在0~1000 mg·kg^(-1),具体数值由定值结果结合不确定度给出,并且该套标准样品均匀性和稳定性良好,应用该标准样品建立的Pb和Cr的标准曲线的相关系数分别为0.9992和0.9989,检出限分别为35和28 mg·kg^(-1),已经达到定量分析能力。为了提高定量分析模型的准确度,需要对标准曲线的数据进一步优化。在数据量较小的情况下,通过对基线类型的多重优化,比较了偏最小二乘法(PLS)和经典最小二乘法(CLS)。实验数据表明,PLS的校正均方根误差(RMSEC)和校正系数(Corr.Coeff)都明显优于CLS。通过优化Pb和Cr的分析波长范围和基线类型,校正曲线的给定值与预测值之间的校正系数达到1.0000,进一步提高了模型的准确度。随机选取一套PP标准样品,对校正曲线进行验证。取高含量样品(PP-306)和低含量样品(PP-302)进行测定,将Pb和Cr的测定数据代入PCRM-PLS模型中,PP-306中Pb和Cr的测定值分别为998和96 mg·kg^(-1),PP-302中Pb和Cr的测定值分别为980和95 mg·kg^(-1),都在给定值范围内,方法有效可靠。Laser-induced breakdown spectroscopy was widely used for quantitative elemental analysis of the field for its rapid,efficient,harmless,full spectrum advantage of direct reading and almost do not need sample preparation.In order to establish a simple method,developed by using polypropylene(PP)plastic reference material(RM),combined with partial least squares(PLS),using laser-induced breakdown spectroscopy(LIBS),the PRM-PLS-LIBS model of Pb and Cr was established.PP reference materials were developed by the requirements of international standards.The content gradient of Pb and Cr were set in the range of 0~1000 mg·kg^(-1)according to the limitation requirements of various countries and regions.The certification results combined with uncertainty gave the specific values,and the certified reference material had good homogeneity and stability.The correlation coefficients of the standard curves of Pb and Cr were 0.9992 and 0.9989,respectively,and the detection limits were 35 and 28 mg·kg^(-1),respectively,which had reached the quantitative analysis ability.In order to improve the accuracy of the quantitative analysis model,it was necessary to optimize the data of standard curve further.Partial least squares(PLS)and classical least squares(CLS)were compared by multiple optimizations of baseline types for small data volume.Experimental results showed that the root mean square error of calibration(RMSEC)and correction coefficient(Corr.Coeff)of PLS were better than that of CLS.By optimizing the analytical wavelength range and baseline type of Pb and Cr,the correction coefficient between the given value and the predicted value of the correction curve reached 1.0000,which further improved the model’s accuracy.A set of PP-certified reference materials were then selected to verify the calibration curve.High content samples(PP-306)and low-content samples(PP-302)were taken for determination,and Pb and Cr determination data were substituted into the PRM-PLS model.The Pb and Cr determination values in PP-306 were 998 and 96 mg

关 键 词：塑料 标准样品 偏最小二乘法 激光诱导击穿光谱法 

分 类 号：O657.31[理学—分析化学]