Assessment of Spatial Variability of Heavy Metals in Metropolitan Zone of Toluca Valley, Mexico, Using the Biomonitoring Technique in Mosses and TXRF Analysis

Table 3

Comparison between measured and reference elements concentration for the IAEA: Standard reference material: IAEA-336 Lichen.

Element	Reference values		Measured values		R	MDL
	Mean; Concentration	SD	Mean; Concentration	SD	%	mg/Kg
	mg/Kg (𝑛=9)
K	1840	±200	1745	±31	95	12
Ca	NR	NR	2253	±172	NC	12
Ti	NR	NR	14.77	±0.87	NC	3.5
V	1.47	±0.22	1.37	±0.12	93	4.0
Cr	1.06	±0.17	0.96	±0.10	91	1.8
Mn	63	±7	62.54	±2.20	99	1.5
Fe	430	±50	396	±22	92	1.2
Ni	NR	NR	ND	NC	NC	NC
Cu	3.6	NR	3.64	±0.21	101	1.3
Zn	30.4	±3.4	34.88	±0.76	105	1.3
Rb	1.76	±0.22	1.70	±0.06	97	0.23
Sr	9.3	±1.1	9.35	±0.16	101	0.23
Pb	4.9	±0.6	4.76	±0.04	97	0.50

SD: standard deviation; R: recovery; NR: not reported; MDL: method detection limited; ND: not detected; NC: not calculated.