Detection Of Typical Heavy Metals In Pork By Dual-pulse Laser Induced Breakdown Spectroscopy

Pork has huge production and consumption in the whole world especially in China.There is the possibility of pigs polluted by heavy metals in the breeding,slaughtering,circulation process,and heavy metals residue in pork is the essential examination item of the hygiene and food safety.Laser induced breakdown spectroscopy(LIBS)is an emission spectrum which can meet the demand of green online detection.This paper presents a feasible methodology to detect heavy metals such as Cd,Pb,and Cr in pork samples by dual-pulse laser induced breakdown spectroscopy(DP-LIBS).In order to probe into the enhanced effect of microwave testing Cd and Pb,this work tests standard material of pork samples by microwave assisted dual-pulse laser induced breakdown spectroscopy(MA-DP-LIBS).The main achievements of this work are summarized as follows:Combining with LIBS spectrum data and concentration of Cd,Pb,Cr for quantitative analysis.After testing pork samples with optimized parameters by LIBS,the concentration of Cd and Pb,Cr were obtained by anodic stripping voltammetry(ASV)and atomic absorption spectrometry(AAS)separately.Then multivariate analysis was carried out on the data.In view of the corresponding model,choosing the best pretreatment method from standard normal variable transformation(SNV),first derivative(FD),second derivative(SD),multiple scattering correction(MSC)and mean centralized(MC).Then set up partial least squares(PLS),interval partial least squares(i PLS)and synergy interval partial least squares(Si PLS)model successively,and compares LIBS spectrum data inspection standard for RMSECV,RMSEP,RC and RP.The results show that the three models can analyze Cd,Pb,and Cr in pork samples,which provide reference for detecting heavy metals in pork by LIBS.In combination with microwave assisted heating paratus for detecting Cd and Pb in standard material of pork samples by LIBS.The results show that MA-DP-LIBS has remarkable enhancement effects for most elements,and it can reduce the detection limit of Pb,but Cd will be covered by other elements under MA-DP-LIBS testing.The results show that MA-DP-LIBS has enhancement effects for Pb in standard material of pork samples.