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 5

(a) Measured concentrations (mg kg⁻¹) in SRM 2976 mussel tissue for target analytes using different digestion procedures. (b) Measured concentrations (mg kg⁻¹) in SRM 1549 nonfat milk powder for target analytes using different digestion procedures. (c) Measured concentrations (mg kg⁻¹) in SRM 1573a tomato leaves for target analytes using different digestion procedures.

(a)

Element	m/z	SRM 2976 mussel tissue
		A	B	C	LSD at 95% CL
Be	9	0.014±0.003	<MDL	<MDL
B	11	20.5±0.6	23.7±0.3	22.7±2.0	ab-a-b-ab-N
Al	27	184±9	204.0±2.0	133±14	a-b-b-a-a
Ti	49	16.5±0.3	28±3	13.3±2.4	a-a-b-a-N
V	51	2.24±0.17	N.Q.	6.9±0.4	a-b-N-c-N
Cr	52	0.597±0.023	1.74±0.05	<MDL	a-b-c-N-b
Mn	55	38.7±0.3	38.1±1.0	38±3	b-b-b-b-a
Fe	56	110±4	112±9	110±10	a-a-a-a-b
Co	59	0.663±0.009	0.637±0.015	0.63±0.06	a-a-a-a-a
Ni	60	0.91±0.04	1.02±0.27	0.68±0.23	ab-ab-b-a-ab
Cu	65	2.745±0.014	2.920±0.028	3.2±0.03	c-a-ab-bc-d
Zn	66	138.7±2.8	137±3	133±11	a-a-a-a-a
As	75	14.77±0.17	12.8±0.3	12.6±1.1	a-a-a-a-a
Se	82	2.90±0.06	1.6±0.5	2.1±0.3	b-b-a-a-a
Sr	88	69.3±0.5	68.7±0.9	68±6	a-a-a-a-b
Mo	98	0.575±0.022	0.486±0.021	0.48±0.04	a-c-b-b-N
Ag	107	0.020±0.004	0.017±0.004	0.014±0.012	N-a-a-a-a
Cd	111	0.91±0.03	0.90±0.07	0.86±0.10	a-a-a-a-a
Sb	123	0.0183±0.0021	0.021±0.004	0.0227±0.0020	b-a-a-a-c
Cs	133	0.1687±0.0015	0.33±0.05	0.17±0.06	N-b-c-b-a
Ba	137	0.636±0.007	0.59±0.04	0.68±0.08	a-a-a-a-N
Tl	205
Pb	208	1.214±0.022	1.11±0.0454	1.15±0.10	a-a-a-a-a
Th	232	0.0167±0.0015	0.0140±0.0026	0.015±0.004	a-a-a-a-a
U	238	0.2430±0.0017	0.243±0.0184	0.237±0.018	a-a-a-a-N

LSD test for the five independent determinations, ordered as follows: (1) from slope and scaling masses; (2) digestion method A (HNO₃); (3) digestion method B (HNO₃ + HCl); (4) digestion method C (HNO₃ + H₂O₂); and (5) certified/reference values; N means nonincluded; low case letters a, b, c, and d are classes ordered from lower to upper values; N.Q.: nonquantified; <MDL: below method detection limit.
Certified/reference values and obtained from slope and scaling masses are shown in Table 4(a).

(b)

Element	m/z	SRM 1549 milk powder
		A	B	C	LSD at 95% CL
Be	9
B	11	3.2±0.6	4.4±0.3	4.0±1.0	a-ab-b-ab-N
Al	27
Ti	49
V	51
Cr	52
Mn	55	0.203±0.013	0.29±0.08	0.23±0.14	a-a-a-a-a
Fe	56
Co	59
Ni	60
Cu	65	0.51±0.07	0.41±0.13	0.58±0.05	a-a-a-a-a
Zn	66	42.7±2.7	42.5±2.2	42.0±2.4	c-ab-a-bc-d
As	75
Se	82
Sr	88	3.51±0.17	3.53±0.20	3.49±0.25	a-a-a-a-N
Mo	98	0.330±0.010	0.310±0.027	0.33±0.03	a-a-a-a-a
Ag	107
Cd	111
Sb	123
Cs	133
Ba	137	0.81±0.05	0.73±0.04	0.80±0.06	b-ab-a-ab-N
Tl	205
Pb	208
Th	232
U	238

LSD test for the five independent determinations, ordered as follows: (1) from slope and scaling masses; (2) digestion method A (HNO₃); (3) digestion method B (HNO₃ + HCl); (4) digestion method C (HNO₃ + H₂O₂); and (5) certified/reference values; N means nonincluded; low case letters a, b, c, and d are classes ordered from lower to upper values; N.Q.: nonquantified; <MDL: below method detection limit.
Certified/reference values and obtained from slope and scaling masses are shown in Table 4(b).

(c)

Element	𝑚/𝑧	SRM 1573a tomato leaves
		A	B	C	LSD at 95% CL
Be	9	0.0127±0.0022	<MDL	<MDL
B	11	30.2±0.4	34.1±1.6	33.8±1.4	a-a-b-b-N
Al	27	567±23	550±50	557±14	a-ab-a-ab-b
Ti	49	24.0±1.7	31±3	25±7	a-ab-b-ab-N
V	51	0.79±0.04	N.Q.	N.Q	a-b-N-N-b
Cr	52	1.65±0.10	2.2±0.4	0.87±0.06	b-bc-d-a-cd
Mn	55	219±6	220±8	226±7	bc-a-a-ab-c
Fe	56	264±10	281±13	290±7	c-a-ab-bc-d
Co	59	0.696±0.019	0.708±0.028	0.737±0.017	c-b-b-bc-a
Ni	60	1.64±0.06	1.78±0.25	1.76±0.08	b-a-ab-ab-a
Cu	65	3.29±0.14	3.24±0.16	3.59±0.08	c-ab-a-bc-d
Zn	66	25.9±0.9	26.4±1.4	27.4±1.7	a-a-a-a-a
As	75	0.149±0.022	0.78±0.14	0.66±0.08	bc-a-ab-ab-c
Se	82
Sr	88	76.9±1.8	75±3	78.0±2.7	a-a-a-a-a
Mo	98	0.362±0.015	0.336±0.017	0.377±0.011	c-b-a-bc-N
Ag	107	0.029±0.018	0.027±0.007	0.015±0.004	a-a-a-a-a
Cd	111	1.47±0.07	1.51±0.07	1.50±0.010	a-a-a-a-a
Sb	123
Cs	133	0.017±0.0020	0.030±0.017	0.020±0.013	ab-a-a-a-b
Ba	137	55.3±2.0	54.0±2.5	56.7±1.4	a-a-a-a-a
Tl	205	0.041±0.026	0.040±0.004	0.042±0.001	a-a-a-a-N
Pb	208	0.548±0.0255	0.49±0.0424	0.539±0.003	c-bc-a-ab-N
Th	232	0.095±0.004	0.088±0.0071	0.100±0.007	ab-a-a-ab-b
U	238	0.0293±0.0021	0.0243±0.0031	0.033±0.004	ab-ab-a-b-b

LSD test for the five independent determinations, ordered as follows: (1) from slope and scaling masses; (2) digestion method A (HNO₃); (3) digestion method B (HNO₃ + HCl); (4) digestion method C (HNO₃ + H₂O₂) and (5) certified/reference values; N means nonincluded; low case letters a, b, c and d are classes ordered from lower to upper values; N.Q.: nonquantified; <MDL: below method detection limit.
Certified/reference values and obtained from slope and scaling masses are shown in Table 4(c).