14
P. Lazo et al.
Table 2.1 The limits of the quantification (LOQ) of the elements (mg k −1 , DW) determined with
a ICP-AES, b ETAAS, c ENAA and d CVAAS analytical methods
Elements a
Mn
Zn
Fe
Al
Cu
Ca
Ba
LOQ
0.007
0.007
0.02
0.035
0.035
0.085
0.085
Elements a
Mg
Sr
Cr
Li
V
Ni
Pb
LOQ
0.085
0.085
0.2
0.2
0.2
0.85
0.85
Elements a
P
Na
K
Cd b
As b
Hg d
LOQ
2.0
8.5
17
0.02
0.035
0.007
Elements c
Ti
Cr
Co
Se
Rb
Sc
Zr
LOQ
63
1.21
0.024
0.071
0.123
0.01
2.79
Elements c
Mo
Sb
Cs
La
Ce
Yb
Hf
LOQ
0.032
0.005
0.0065
0.02
0.456
0.035
0.021
Elements c
Ta
W
Th
U
LOQ
0.002
0.019
0.005
0.0026
a,b Qarri et al. 2013, c,d Lazo et al. 2018
Three replicates per moss samples were digested and three replicate measurements
per digests were made during the analysis. The limits of the quantification (LOQ) for
the elements determined with both ICP and ENAA methods are shown in Table 2.1.
The limits of quantification were calculated as 10 SD of the lowest instrumental
measurements of the blanks (Qarri et al. 2013, Lazo et al. 2018).
2.2.3 Sample Preparation and ENAA Analysis
Extraneous materials, dead materials, and litter were removed from moss samples.
The cleaned green and green-brownish parts of the moss (H. cupressiforme (Hedv.)
sps.) that represent at last 3 years of moss growth, were selected for analysis. Samples
were dried for 48 h at 40 °C till the constant weight and were analyzed by instrumental
neutron activation analysis (INAA). Previous experience from the use of neutron
activation analysis (NAA) in moss biomonitoring had shown that 0.3 g moss samples
are sufficiently enough to be used without homogenization (Steinnes et al. 1994).
This procedure is still in use for routine analysis at the Frank Laboratory of Neutron
Physics, Joint Institute for Nuclear Research (FLNP JINR) (Frontasyeva et al. 2004;
Barandovski et al. 2008; Marinova et al. 2010; Allajbeu et al. 2016). Epithermal
NAA at the IBR-2 pulsed fast reactor of the FLNP JINR, Dubna, Russia, was used to
determine contents of metals in moss samples (Frontasyeva 2011). Pulsed fast reactor
IBR-2, equipped with pneumatic system REGATA for INAA, provides activation
with thermal, epithermal, and fast neutrons. ENAA is an extension of INAA that
enhances the activation of a number of trace elements relative to the major matrix
elements (Frontasyeva and Pavvlov 2000).
P. Lazo et al.
Table 2.1 The limits of the quantification (LOQ) of the elements (mg k −1 , DW) determined with
a ICP-AES, b ETAAS, c ENAA and d CVAAS analytical methods
Elements a
Mn
Zn
Fe
Al
Cu
Ca
Ba
LOQ
0.007
0.007
0.02
0.035
0.035
0.085
0.085
Elements a
Mg
Sr
Cr
Li
V
Ni
Pb
LOQ
0.085
0.085
0.2
0.2
0.2
0.85
0.85
Elements a
P
Na
K
Cd b
As b
Hg d
LOQ
2.0
8.5
17
0.02
0.035
0.007
Elements c
Ti
Cr
Co
Se
Rb
Sc
Zr
LOQ
63
1.21
0.024
0.071
0.123
0.01
2.79
Elements c
Mo
Sb
Cs
La
Ce
Yb
Hf
LOQ
0.032
0.005
0.0065
0.02
0.456
0.035
0.021
Elements c
Ta
W
Th
U
LOQ
0.002
0.019
0.005
0.0026
a,b Qarri et al. 2013, c,d Lazo et al. 2018
Three replicates per moss samples were digested and three replicate measurements
per digests were made during the analysis. The limits of the quantification (LOQ) for
the elements determined with both ICP and ENAA methods are shown in Table 2.1.
The limits of quantification were calculated as 10 SD of the lowest instrumental
measurements of the blanks (Qarri et al. 2013, Lazo et al. 2018).
2.2.3 Sample Preparation and ENAA Analysis
Extraneous materials, dead materials, and litter were removed from moss samples.
The cleaned green and green-brownish parts of the moss (H. cupressiforme (Hedv.)
sps.) that represent at last 3 years of moss growth, were selected for analysis. Samples
were dried for 48 h at 40 °C till the constant weight and were analyzed by instrumental
neutron activation analysis (INAA). Previous experience from the use of neutron
activation analysis (NAA) in moss biomonitoring had shown that 0.3 g moss samples
are sufficiently enough to be used without homogenization (Steinnes et al. 1994).
This procedure is still in use for routine analysis at the Frank Laboratory of Neutron
Physics, Joint Institute for Nuclear Research (FLNP JINR) (Frontasyeva et al. 2004;
Barandovski et al. 2008; Marinova et al. 2010; Allajbeu et al. 2016). Epithermal
NAA at the IBR-2 pulsed fast reactor of the FLNP JINR, Dubna, Russia, was used to
determine contents of metals in moss samples (Frontasyeva 2011). Pulsed fast reactor
IBR-2, equipped with pneumatic system REGATA for INAA, provides activation
with thermal, epithermal, and fast neutrons. ENAA is an extension of INAA that
enhances the activation of a number of trace elements relative to the major matrix
elements (Frontasyeva and Pavvlov 2000).