“After Wilcoxon-Mann-Whitney test and correlation analysis, 10 … (P, V, Cr, Ni, Cu, Zn, As, Se , Pb, U) and 7 element ratios (U/Ba, Ba/Pb, Cd/Mn, Co/…/Cr, P/V, Cd/V) were found to be evidently different between heroin samples from "Golden …" and "Golden Triangle".”