Id | Sample description | AVG (n = 2) [mg kg−1 Cu] | RSD [%] | Remarks |
A B C D E F G
| PE reference, batch (1) PE pigment starting material Cake Intermediate pigment, treated with MTBE Cake Intermediate pigment, treated with MTBE, H2O and H2SO4 Base material LDPE 1965 PE reference, batch (2) ERM-EC680m Low-density olyethylene Limit of Detection Cu | 4.6 47 3.9 13 0.05 16 12.5 0.1 | 14 18 13 9 (“125”) 100 10
| High deviation; processing background High deviation High deviation Low deviation Background Concentration/raw Very high deviation also compared with A Processing background Used as internal control sample (Cu not certified) |