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 4

(a) Measured (from slope) and certified/reference concentrations (mg kg⁻¹) for the target analytes in the SRM 2976 mussel tissue. (b) Measured (from slope) and certified/reference concentrations (mg kg⁻¹) for the target analytes in the SRM 1549 nonfat milk powder. (c) Measured (from slope) and certified/reference concentrations (mg kg⁻¹) for the target analytes in the SRM 1573a tomato leaves.

(a)  

Element	𝑚/𝑧	SRM 2976 mussel tissue
		From slope	certified/reference		Stat.
Be	9	N.L.
B	11	22.5±1.0			Aa
Al	27	140±11	R	134±4	Ab-Ca
Ti	49	15.02±0.57			Aa
V	51	1.39±0.10			Ab
Cr	52	0.324±0.029	R	0.50±0.16	Ab-Ca
Mn	55	37.1±1.2	R	33.0±2.0	Aa-Ca
Fe	56	112.3±7.5	C	171.0±4.9	Aa-Cb
Co	59	0.644±0.021	R	0.61±0.02	Aa-Ca
Ni	60	0.82±0.04	R	0.93±0.12	Ab-Ca
Cu	65	3.35±0.17	C	4.02±0.33	Ab-Ca
Zn	66	137±6	C	137±13	Aa-Ca
As	75	14.6±0.5	C	13.3±1.8	Aa-Ca
Se	82	2.75±0.23	C	1.80±0.15	Aa-Cb
Sr	88	67.0±2.4	R	93±2	Aa-Cb
Mo	98	0.412±0.025			Ab
Ag	107	N.L.; <MDL	R	0.011±0.005
Cd	111	0.938±0.03	C	0.82±0.16	Aa-Ca
Sb	123	N.L.
Cs	133	N.L.; <MDL	R	0.027±0.001
Ba	137	0.65
Tl	205	N.L.
Pb	208	1.19±0.04	C	1.19±1.18	Aa-Ca
Th	232	0.0123±0.0035	R	0.011±0.002	Bb-Ca
U	238	0.244±0.008			Aa

Statistical analysis: first (capital) refers to linear fit: A > 99% CL, B > 95% CL; C > 90% CL. Second (lower case) refers to the ordinate in origin: not significantly different from zero at 99% CL; b, else. Third refers to the comparison between measured and certificated/reference values: Ca not statistically significant difference at 95% CL, Cb, else. For those reference values without associated uncertainties, relative errors of 20% have been assumed.
N.L: nonpositive linear relationship; <MDL: below method detection limit;
R: reference value; C: certified value.

(b)  

Element	𝑚/𝑧	SRM 1549 nonfat milk powder
		From slope	certified/reference		Stat.
Be	9	N.L.
B	11	2.8±0.7			Ba
Al	27	N.L.; <MDL	R	2.0
Ti	49	2.63±0.17			Aa
V	51	N.L.
Cr	52	N.L.; <MDL	C	0.0026±0.0007
Mn	55	0.254±0.010	C	0.26±0.06	Ab-Ca
Fe	56	N.L.; <MDL	C	1.78±0.1
Co	59	<MDL	R	0.0041
Ni	60	0.308±0.027			Ab
Cu	65	0.71±0.29	C	0.70±0.1	Ca-Ca
Zn	66	43.9±1.4	C	46.10±2.2	Aa-Ca
As	75	<MDL	R	0.0019
Se	82	<MDL	C	0.110±0.010
Sr	88	3.68±0.12			Aa
Mo	98	0.350±0.017	R	0.34	Aa-Ca
Ag	107	<MDL	R	<0.0003
Cd	111	<MDL	C	0.0005±0.0002
Sb	123	<MDL	R	0.00027
Cs	133	N.L.
Ba	137	0.87±0.04			Aa
Tl	205	N.L.; <MDL
Pb	208	<MDL	C	0.019±0.003
Th	232	N.L.
U	238	N.L.

Statistical analysis: first (capital) refers to linear fit: A > 99% CL; B > 95% CL; C > 90% CL. Second (lower case) refers to the ordinate in origin: not significantly different from zero at 99% CL; b, else. Third refers to the comparison between measured and certificated/reference values: Ca not statistically significant difference at 95% CL, Cb, else. For those reference values without associated uncertainties, relative errors of 20% have been assumed.
N.L: nonpositive linear relationship; <MDL: below method detection limit;
R: reference value; C: certified value.

(c)  

Element	𝑚/𝑧	SRM 1573a tomato leaves
		From slope	certified/reference		Stat.
Be	9	0.0274±0.0016			Ab
B	11	30.5±1.1			Aa
Al	27	543±12	C	598±12	Aa-Cb
Ti	49	22.6±1.6			Aa
V	51	0.56±0.05	C	0.835±0.010	Ab-Cb
Cr	52	1.51±0.06	C	1.99±0.06	Ab-Cb
Mn	55	236±9	C	246±8	Aa-Ca
Fe	56	301±8	C	368±7	Ab-Cb
Co	59	0.756±0.022	C	0.57±0.02	Aa-Cb
Ni	60	1.93±0.10	C	1.590±0.07	Ab-Cb
Cu	65	3.85±0.23	C	4.70±0.14	Aa-Cb
Zn	66	29.0±1.8	C	30.90±0.7	Aa-Ca
As	75	0.063±0.008	C	0.112±0.004	Ab-Cb
Se	82	<MDL	C	0.054±0.003
Sr	88	78.2±1.8	R	85	Aa-Ca
Mo	98	0.400±0.010			Aa
Ag	107	0.016±0.004	R	0.017	Aa-Ca
Cd	111	1.56±0.04	C	1.52±0.04	Aa-Ca
Sb	123	0.035±0.002	C	0.063±0.006	Aa-Cb
Cs	133	0.036±0.005	R	0.053	Ab-Ca
Ba	137	57.6±1.6	R	63	Aa-Ca
Tl	205	0.0444±0.0018			Aa
Pb	208	0.594±0.016			Aa
Th	232	0.101±0.003	R	0.120	Aa-Ca
U	238	0.0298±0.0015	R	0.035	Aa-Ca

Statistical analysis: first (capital) refers to linear fit: A > 99% CL; B > 95% CL; C > 90% CL. Second (lower case) refers to the ordinate in origin: not significantly different from zero at 99% CL; b, else. Third refers to the comparison between measured and certificated/reference values: Ca not statistically significant difference at 95% CL, Cb, else. For those reference values without associated uncertainties, relative errors of 20% have been assumed.
N.L: nonpositive linear relationship; <MDL: below method detection limit;
R: reference value; C: certified value.