Determination of 25 Trace Element Concentrations in Biological Reference Materials by ICP-MS following Different Microwave-Assisted Acid Digestion Methods Based on Scaling Masses of Digested Samples

Table 3

Method detection limits (concentrations in mg kg⁻¹) determined for laboratory blank solutions.

Element	m/z	Equation^#	Procedure
			A	B	C
Be	9		0.010	0.010	0.009
B	11		0.76	0.85	0.69
Al	27		2.9	4.7	2.0
Ti	47		2.5	1.4	3.5
V	51	(1)	0.12	0.69	0.44
V	51		0.12	N.R.	0.91
Cr	52		0.055	1.9	0.047
Mn	55		0.033	0.11	0.039
Fe	56		10.2	9.8	8.6
Co	59		0.012	0.013	0.024
Ni	60		0.15	0.38	0.12
Cu	63		0.33	0.71	0.44
Cu	65		0.50	0.27	0.17
Zn	66		1.4	0.61	0.36
As	75		0.020	N.R.	0.20
As	75	(2)	0.27	0.86	0.20
Se	82	(3)	0.87	1.4	0.89
Se	82		0.88	0.89	0.97
Sr	88		0.045	0.014	0.028
Mo	95		0.26	1.13	0.32
Ag	107		0.081	0.013	0.009
Cd	111	(4)	0.083	0.055	0.081
Sb	123		0.005	0.004	0.007
Cs	133		0.014	0.028	0.023
Ba	137		0.059	0.063	0.20
Tl	205		0.003	0.006	0.006
Pb	208	(5)	0.024	0.017	0.090
Th	232		0.005	0.003	0.007
U	238		0.002	N.Q.	0.003

Procedures: A (HNO₃) and B (HNO₃ + HCl) use dilution factors of 0.6 g L⁻¹, while 0.5 g L⁻¹ is applied for procedure C (HNO₃ + H₂O₂). In the three cases, 0.5 g of dry sample was digested. For the variations of method A with different amount of sample, 𝑚_𝑖 (g), the corresponding MDLs have to be corrected by a factor of 0.5/𝑚_𝑖.
^#Correction equations from Table 2.
N.R.: not recommended; N.Q.: not quantified.