. 2023 Jan 24;9(3):e13174. doi: 10.1016/j.heliyon.2023.e13174

Table 6c.

Validation method for quantitative analysis of essential and toxic metals in saltpetre samples.

Sample	OREAS45EA Standard Reference Material	Measured value (mg kg⁻¹)
Ca	360	17700–40700
K	530	16200–52400
Fe	235100	2300–3100
Zn	31.40	4.6–10
As	3.70	2.7–11.1
Cd	0.03	0.01–0.02
Hg	0.010	0.008
Pb	14.30	0.85–1.25