Parameters of 15 REEs and lead detection methods (ug/g).

Table 1: Parameters of 15 REEs and lead detection methods (ug/g).

Elements	SD	Linear correlation coefficient	Detection limit	Elements	SD	Linear correlation coefficient	Detection limit
La	0.0040	0.9995	0.0119	Dy	0.0010	0.9996	0.0030
Ce	0.0107	0.9994	0.0320	Ho	0.0006	0.9993	0.0018
Pr	0.0013	0.9993	0.0039	Er	0.0004	0.9994	0.0011
Nd	0.0044	0.9998	0.0133	Tm	0.0004	0.9992	0.0012
Sm	0.0013	0.9996	0.0039	Yb	0.0008	0.9993	0.0025
Eu	0.0007	0.9996	0.0022	Lu	0.0006	0.9990	0.0017
Gd	0.0010	0.9996	0.0031	Y	0.0083	0.9993	0.0250
Tb	0.0000	0.9993	0.0000	Pb	0.6696	0.9994	2.0088