C were found among the four grinding methods. We estimated plastic abrasion to be 1.65 mg. Our results show that the use of ball milling for homogenising samples for C and N stable isotope analysis does not affect animal muscle samples with a commonly used amount of material (∼50 mg). Finally, we provided a graphical recommendation on the minimum amount of sample to be ground by milling without incurring in plastic contamination bias.
Balzani et al. (2026) studied this question.