Laser-Induced Breakdown Spectroscopy for Rapid Discrimination of Heavy-Metal-Contaminated Seafood Tegillarca granosa.

Guoli Ji,Xiaojing Chen,Leiming Yuan,Dehua Zhu,Xi Chen,Mingshun Yuan,Jing Jiang,Xinyu Hu,Pengchao Ye,Yijian Shi

doi:10.3390/s17112655

Abstract

Tegillarca granosa samples contaminated artificially by three kinds of toxic heavy metals including zinc (Zn), cadmium (Cd), and lead (Pb) were attempted to be distinguished using laser-induced breakdown spectroscopy (LIBS) technology and pattern recognition methods in this study. The measured spectra were firstly processed by a wavelet transform algorithm (WTA), then the generated characteristic information was subsequently expressed by an information gain algorithm (IGA). As a result, 30 variables obtained were used as input variables for three classifiers: partial least square discriminant analysis (PLS-DA), support vector machine (SVM), and random forest (RF), among which the RF model exhibited the best performance, with 93.3% discrimination accuracy among those classifiers. Besides, the extracted characteristic information was used to reconstruct the original spectra by inverse WTA, and the corresponding attribution of the reconstructed spectra was then discussed. This work indicates that the healthy shellfish samples of Tegillarca granosa could be distinguished from the toxic heavy-metal-contaminated ones by pattern recognition analysis combined with LIBS technology, which only requires minimal pretreatments.

Highlights

Due to the recent accelerated process of industrialization in developing countries, a large number of toxic heavy metals are discharged into rivers, lakes, and seas
A rapid discrimination method of toxic heavy-metal-contaminated Tegillarca granosa was investigated in this study by combining laser-induced breakdown spectroscopy (LIBS) and pattern recognition
Results show that the random forest (RF) model demonstrates the highest elemental discrimination ratio of 93.3% for different types of Tegillarca granosa

Summary

Introduction

Due to the recent accelerated process of industrialization in developing countries, a large number of toxic heavy metals are discharged into rivers, lakes, and seas. The toxic heavy metal pollution of aquatic products has become an increasingly serious issue. Toxic heavy metals disrupt the living condition of aquatic animals in natural water resources and intoxicate or kill aquaculture fish, which turns out to be a threat to the fish farming industry. Heavy metal ions accumulate in the human body from the consumption of the polluted seafood [1,2]. Many enzymes in the human body will be deactivated by heavy metals, leading to the risk of chronic poisoning.

Methods

Discussion

Conclusion