热解炭化病死猪残留重金属的激光诱导击穿光谱检测可行性分析

Feasibility of LIBS in detecting heavy metal residues in diseased dead pig treated by pyrolytic carbonization

利用激光诱导击穿光谱（LIBS）分析方法具有的快速无污染优势，选择有代表性的病死猪为研究对象，探讨LIBS对病死猪中残留重金属元素的预测可行性。为了消除水分和有机基体对LIBS分析灵敏度的影响，对病死猪采取高温热解炭化前处理，分别比较了健康猪肉鲜样、健康猪肉真空抽湿压片样和病死猪热解炭化压片样在320～440nm范围的LIBS光谱信息。结果显示，猪肉中含有丰富的ca等矿质元素及有机质成分C，N等；真空抽湿可以消除水分的影响从而提高LIBS分析重金属的灵敏度，而热解炭化可以大大减弱含水量和有机质成分对金属元素的干扰，能够探测出更多的元素谱线信息，同时进一步提高重金属Cu，Pb和Cr的检测灵敏度。表明LIBS能对解热炭化病死猪中的残留重金属成分进行探测，并有望结合化学计量学分析方法实现猪肉中重金属含量的快速检测。

Laser induced breakdown spectroscopy（ LIBS） is an emerging method in analyzing compositions of substance.The most figure of merit of LIBS lies in fast and environmental-friendly characteristic,especially in detecting the quality and safety,such as heavy metal residues,in agricultural products.In this work,diseased dead pig was chosen as the target to verify the feasibility of LIBS in predict the heavy metal residues in pork.To improve the sensibility of LIBS,samples of pork from diseased dead pigs were treated by pyrolytic carbonization,shattered and pressed to pellets.At the same time,original healthy fresh pork without any treatment and healthy pork treated by vacuum drainage for producing dry samples and finally pressed.The three varies of samples were detected by LIBS at the same experimental parameters.The results showed that vacuum drainage can eliminate the effect of water content,and increase the LIBS sensitivity.In addition,pyrolytic carbonization can decrease the effect of both water and organic matrix,and LIBS sensitivity can be further improved.LIBS signal of some heavy metals,such as Cu,Pb and Cr,is clear in samples after pyrolytic carbonization.This work demonstrated that it is promising to detect the heavy metals in pork treated by pyrolytic carbonization,and this method can evaluate the safety of pork.