Table 2.

Tissue concentrations (ng/g) and relative tissue concentrations (eq. 2) of methylphenidate and ritalinic acid in stickleback and water louse from study 2. Start sampling occurred 60 min after dosing. Values are shown as mean ± s.d. (range). Ranges are not given for single values. End sampling occurred on the final sampling day. LOQ limit of quantification, NA not applicable

	Start (ng/g)	Start relative tissue concentration	End (ng/g)	End relative tissue concentration
Stickleback (muscle tissue)
10 °C methylphenidate	0.18 ± 0.05 (0.13–0.28)	1.2 ± 0.5 (0.7–2.1)	< LOQ	NA
20 °C methylphenidate	0.12 ± 0.02 (0.10–0.14)	0.5 ± 0.1 (0.4–0.7)	< LOQ	NA
10 °C ritalinic acid	< LOQ	NA	< LOQ	NA
20 °C ritalinic acid	< LOQ	NA	< LOQ	NA
Water louse (whole-body)
10 °C methylphenidate	0.1	0.6	0.2 ± 0.1 (0.1–0.3)	7.5 ± 3.2 (4.0–10.4)
20 °C methylphenidate	0.2	1.1	0.1	50.0
10 °C ritalinic acid	< LOQ	NA	< LOQ	NA
20 °C ritalinic acid	< LOQ	NA	< LOQ	NA