Table 3.

SEM/SDD-EDS analysis of NIST SRM K411 glass

Element	SRM certificate	EDS analysis	SDa	Relative error (%)
O	0.424	0.428 (stoich)	0.022	0.9
Mg	0.0885	0.0876	0.045	−1.1
Si	0.254	0.258	0.053	1.6
Ca	0.111	0.111	0.026	0
Fe	0.112	0.114	0.031	1.8

Conditions: polished specimen; E ₀ = 20 keV; analysis following the k-ratio protocol with standards using the NIST DTSA-II software; standards included the pure elements Mg, Si, and Fe; Ca from SRM 470 (glass K412), with oxygen calculated on the basis of assumed stoichiometry of the cations

^a20 analyses