Table 1.

Elemental and isotopic analysis of reference materials for method validation.

Material	n (m)	Mg ± 1SD (mg L−1)	n (m)	Measured δ26MgDSM3 ± 2SD (‰)	Measured δ25MgDSM3 ± 2SD (‰)	Reported δ26MgDSM3 ± 2SD (‰)	Reported δ25MgDSM3 ± 2SD (‰)	References
CPI Mg	-		25	−1.41 ± 0.11	−0.73 ± 0.06	−1.39 ± 0.08	−0.73 ± 0.04	[30]
Seronorm serum L-1	2(2)	20.1 ± 0.4	5(2)	0.08 ± 0.10	0.03 ± 0.05	0.12 ± 0.11	0.06 ± 0.06	[30]
						0.13 ± 0.11	0.06 ± 0.06	[31]
						0.08 ± 0.06	0.04 ± 0.05	[25]

n = number of measurements performed, m = number of separate aliquots digested. 1SD = standard deviation, 2SD = standard deviation multiplied by two.