Mineral Elements Analysis And Preliminary Research Of Element Fingerprint Information Of Four Commercial Fishes In Coastal Area Of East China Sea

With the rapid economic development, industrial pollution has induced varied degrees of heavy metal pollution in coastal water, whose transfer and enrichment in the food chains will result in serious harm to the consumers. So safety problem of aquatic products has been increasingly prominent. U.S., EU and other major aquatic products importers, as well as some domestic provinces and cities havd began to implement market access system and establish tracing platform of aquatic product origin to ensure that aquatic sources can be verified. And there is regional diversity among commercial fishes from different origins. Therefore, the establishment of mineral element fingerprint information in commercial fishes can be used for monitoring pollution hazard and assessment of nutritional value, as well as identifying the origin of products, which are important to the establishment of commercial fishes origin tracing platform, consumer health, crude material supervising in processing factory, the healthy development of aquaculture and so on.Firstly, two analytical methods, MD-FAAS and MD-GFAAS, were established and respectively employed to the quantitative analysis of K, Na, Ca, Mg, Cu, Fe and Pb, Cd, Cr in sea-fish. In MD-FAAS, the optimization of pre-treatment, instrument parameters was carried out, and interference of the coexist ions, effect of acid medium, organic reagents and surfactant on sensitivity of measured elements were also investigated. Then,0.02%SDS and0.06%SDS were respectively added in the analysis of Cu, Fe and K, Ca, Mg which enhanced the sensitivity of these elements. In MD-GFAAS, pre-treatment conditions, instrument parameters, temperature program of GFAAS and the addition of matrix modifiers were optimized. The results showed that favorable linear correlation of the elements(r2:0.9983～0.9998) was obtained, and the characteristics such as simple pretreatment, high sensitivity, favourable ability of anti-interference were both observed in two methods. The precision (RSD<5%) and recovery ratio (86.67%～110.91%) also met the requirements of analysis.Secondly, this study respectively established two methods based on microwave digestion-inductively coupled plasma mass spectrometry (MD-ICP-MS) for the simultaneous analysis of20mineral elements(Mn, Co, Cu, Fe, Zn, Se, Rb, Sr, Mo,etc.) and the analysis of trace element iodine, which included the optimization of pre-treatment conditions and instrument parameters, selection of monitoring isotope, interference test and elimination of interferences, influence of organic media on sensitivities and so on. Then1.0%and2.5%of methanol were respectively added in the multi-element analysis and trace I analysis, which improved the sensitivity of elements with high ionization potential, such as As, Hg, Se, I. As the results showed, favorable linear correlation(r2:0.9995～0.9999) was obtained, and the characteristics such as simple pretreatment, high sensitivity, low limit of detection, remarkable efficiency and accuracy of analysis, favourable ability of anti-interference were both observed in two methods. The precision (RSD<6%) and recovery (81.74%～109.51%) of them also met the analytical requirements.Subsequently, the performance of analytical methods were compared, and MD-FAAS was selected for the determination of4macroelements(K, Na, Ca, Mg) in commercial sea-fish samples (pomfret, hairtail, squid, pseudosciaena polyactis) from three maritime origins(Zhoushan, Wenzhou, Ningbo). And MD-ICP-MS was employed for the multi-element analysis of20elements (Mn, Co, Cu, Fe, Se,etc) and the determination of I. Elements composition in different samples was subsequently obtained. Then, mineral elements distribution characteristic, safety assessment which based on related standards and risk assessment model were carried out for different commercial sea-fishes. The results showed that, in same species, Mn, Co, Zn, Rb, Sr, Mo, Ba, Bi and some other mineral elements content had a significant difference between three maritime origins, which proved the origin identification of fishes based on element fingerprint was feasibility. In addition, the mineral elements content also differed between species. And except the indeterminacy of inorganic arsenic content and that risk value of As was relatively large (risk class V), content of other elements fitted the criterions and the risk values of Fe, Cu, Mn, Zn, Pb, Hg, Cr, Cd were in the acceptable range.Finally, three kinds of multivariate statistical analysis methods, Principal Component Analysis (PCA), Partial Least Squares Discriminant Analysis (PLS-DA) and Probabilistic Neural Network (PNN) were used to analyse the information of elements composition in four commercial fishes from different origins. Then, origin discriminant was performed on the basis of mineral element fingerprint characteristics. The results showed that PCA can fully distinguish the commercial fishes from different areas, and the elements which played most important role in origin diversity were also found. The discriminant models established by PLS-DA, PNN can both forecast the origin of four commercial fishes precisely, validation results showed that the accuracy both reached100%. Without regard to the species, the discriminant models of multi-fish established by PLS-DA and PNN can both distinguish the commercial fishes from different areas. The accuracy of them respectively reached97.92%and100%. Therefore, the origin discriminant technique based on mineral element fingerprint can be a efficacious application in four kinds of commercial fishes from three origins.