猪饲料中Cu元素的空间限域LIBS检测  

Laser-Induced Breakdown Spectroscopy Detection of Cu Element in Pig Fodder by Combining Cavity-Confinement

作　　者：吴书佳 姚明印[2,3] 曾剑辉 何梁 付港荣 曾瑜琦 薛龙 刘木华[2,3] 黎静 WU Shu-jia;YAO Ming-yin;ZENG Jian-hui;HE Liang;FU Gang-rong;ZENG Yu-qi;XUE Long;LIU Mu-hua;LI Jing(College of Software,Jiangxi Agricultural University,Nanchang 330045,China;College of Engineering,Jiangxi Agricultural University,Nanchang 330045,China;Key Laboratory of Modern Agricultural Equipment,Jiangxi Province,Nanchang 330045,China)

机构地区：[1]江西农业大学软件学院,江西南昌330045 [2]江西农业大学工学院,江西南昌330045 [3]江西省现代农业装备重点实验室,江西南昌330045

出　　处：《光谱学与光谱分析》2023年第6期1770-1775,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(31960363)资助。

摘　　要：近年来,猪饲料重金属超标问题屡禁不止,严重危害食用人群健康与环境安全。国家标准中所采用的干灰化-原子吸收光谱法存在耗时长、需破坏样品、试剂易造成环境污染等问题。激光诱导击穿光谱(LIBS)以其快速、近乎无损、无需复杂制样的检测特性被誉为化学分析领域的“未来巨星”。传统LIBS技术在应用于猪饲料安全品质检测时具有特征光谱强度弱,检测精度较低等缺陷,针对该缺陷,提出LIBS技术与空间限域相结合,采用空间限域方法提高分析谱线强度,从而实现更低浓度样品的检出,实现对猪饲料样品中Cu元素含量进行快速绿色检测。以CuⅠ324.75 nm为分析谱线,在优化后的能量下,对比不同延时时间下加载不同高度和直径的圆柱形空间限域腔对分析谱线影响,再选取对分析谱线整体增强效果最佳的空间限域腔对7组不同浓度猪饲料样品进行LIBS光谱采集,结合采用国家标准方法获取的7组猪饲料样品中Cu元素参考浓度对LIBS系统检测灵敏度进行分析。结果表明,加载空间限域腔对分析谱线强度引起增强的同时不会对背景光谱造成明显影响,分析谱线强度增强因子最大值为5.16,空间限域腔直径为5.0 mm、高度为2.0 mm情况下对分析谱线整体增强效果最佳。在上述最佳试验参数基础上,以Cu元素在324.75 nm处特征光谱峰值强度为参考,对猪饲料进行定量分析。结果发现加载空间限域腔后不同浓度下猪饲料样品中Cu元素浓度与分析谱线强度之间线性关系相较于传统LIBS提升明显,其单变量定标模型R^(2)从0.742提升至0.996,检测限从6.21 mg·kg^(-1)降低至1.61 mg·kg^(-1)(《饲料添加安全使用规范》中猪类Cu元素日粮推荐含量为3~6 mg·kg^(-1)),检测灵敏度提高了2.86倍。研究表明,采用空间限域与LIBS技术相结合,可以大幅提升系统检测精度与灵敏度,使待测元素检测限降低至国家要求以下,�In recent years,the problem of excessive heavy metals in pig fodder has been repeatedly banned,which has seriously endangered the health of people who eat pork and the environment’s safety.The dry ashing-Atomic Absorption Spectroscopy as the national standard text method faces problems such as being time-consuming,sample destruction,and environmental pollution caused by reagents.Laser-induced breakdown spectroscopy(LIBS)is known as the“future superstar”in chemical analysis for its fast,nearly non-destructive,and no need for complex sample preparation.Traditional LIBS technology has the disadvantages of weak characteristic spectrum intensity and low detection accuracy when applied to pig fodder safety and quality inspection.In response to this defect,it is proposed to combine LIBS technology with cavity-confinement and use the cavity-confinement method to improve the intensity of the analysis spectrum.In this way,the detection of lower concentration samples and the rapid green detection of Cu element content in pig fodder samples are realized.Take CuⅠ324.75 nm as the analysis line,under the optimized energy,it compares the influence of loading cylindrical cavity-confinement cavity with different heights and diameters under different delay times on the analysis line.Then it selects cavity-confinement cavity which has perfect overall enhancement effect of the analysis line to collect the LIBS spectrum of 7 groups of pig fodder samples with different concentrations.Then the sensitivity of the LIBS system was analyzed in combination with the reference concentrations of Cu elements in seven groups of pig feed samples obtained using national standard methods.The results show that loading the cavity-confinement cavity causes enhancement of the analyzed spectral lines’intensity without significantly affect for the background spectrum.Under the maximum enhancement factor of the analysis spectral line intensity is 5.16,the diameter of the cavity-confinement cavity is 5.0 mm,and the height is 2.0 mm.The overall enh

关 键 词：激光诱导击穿光谱 空间限域 猪饲料 铜 检测灵敏度 

分 类 号：O657.3[理学—分析化学]