Analysis of Heavy elements, Cr, As, Hg, Cd, Pb in soil sample by ICP-MS and ICP-OES and study of the distribution by Geochemometrics

In this study distribution and effect of heavy elements, Pb, Cd, Hg, As, Cr on soil samples of Saduq in Yazd province was investigated. 335 soil samples were taken in Saduq, SS for Saduq, No for Nodushan and KH for Khezrabad was taken according to standard sampling methods. Sample digestion was done according to ASTM D4698 by 4-acid and fusion methods [1]. Analysis was done by ICP-MS, ICP-OES and AF and resulted data were processed by Geochemometrics methods. The concept of Geochemoemtrics contain Geo means the Earth and Chemometric which is a new method for receiving the most profitable data from a huge mass of complicated data [2]. PCA is the most useful mathematical method in chemometrics. The most important results of PCA algorithm are Score and Loading Plots and Biplot diagram which all help to have a better interpretation from gathered data. KNN method is used for classification and determination of the coherence between data [3]. The analysis of principle components was done according to heavy metals and three main components are PC1=22.94%, PC2=19.42% and PC3=16.91% which contain more that 59% of the change. Distribution of samples was studied according to the Score plots of the first and second principle components and SS158, SS156, SS154 in Saduq, NO-L29 and NO-S-10 in Nodushan and KH-S-23 in Khezrabad has got a significant variance. The effect of elements on samples was investigated by Biplot diagram and results show that AS and Cd has got an effect on distribution of NO-S-10, NO-L-29 and KH-S-23 respectively. According to the studies about T2-Hotelling the significant difference in KH-S-23, NO-L-29, NO-S-10, SS154, SS141 was obvious. KNN was used to study the correlation and clustering of elements and results show that Cd and Pb have got relative correlation in this region. In this plot B and Cr were placed in a different classification in compare with other elements also Hg and Cd are in this classification and have got closer correlation with As and Pb in comparison with Cr and B. Results show that ICP-MS and ICP-OES analyses have got good accuracy and precision and the method is applicable in determination of trace elements in Geology. The method was presented to the Geology reference laboratory.