Table 1.

Assigned and determined and results on the trace element concentrations in biological control materials (mg kg^-1 dw) (n = 3)

Element	Control material*
	CM CS-M-3		CRM CS-M-4
	Assigned	Determined	Assigned	Determined
Hg	2.849±0.104	2.759±0.075	0.463 ± 0.024	0.438±0.031#
Se	16.21 ± 0.85	17.43 ± 1.36	1.29 ± 0.08	1.29 ± 0.03

Notes: *Control reference materials: CM CS-M-3 (dried mushroom powder Boletus edulis) and CM CS-M-4 (dried mushroom powder Leccinum scabrum)—produced by the Institute of Nuclear Chemistry and Technology, Warsaw, Poland; WD (without data); ^#(n = 11)