17.2.3 Methods of Determination of the
90
Sr and
137
Cs
Concentration in Natural Objects
The method of
90 Sr determination in hydrobionts, water and bottom sediments was
based on: carrying out of radiochemical procedure of the strontium
preconcentration, then purification from interfering elements, measuring of the
90
Y (the daughter product) activity on Cerenkov’s radiation and subsequent mathematical data processing (Harvey et al. 1989; Instrument description 1989,
«Quantulus 1220»). Analysis was carried out with the use of the low background
liquid-scintillation counter (LSC) LKB “Quantulus 1220”. The lower limit of
detection (LLD) was 0.01–0.04 Bq kg
À1 (for hydrobionts and bottom sediments)
and Bq m
À3 (for water samples). Recoveries are calculated from Sr-stable recovery
by flame photometry for the
90 Sr and then gravimetrically from yttrium oxalate for
90 Y (Harvey et al. 1989; Instrument description «Quantulus 1220», Polikarpov et al.
2008). Each result is reported as the mean of the values activity of parallel
repeatability samples, which were measured separately. Total relative error of the
each result does not exceed 20%.
The sorption method of determination of radioisotopes of caesium of
137 Cs in
water ecosystems is based on principle of carrying out of their gammaspectrometric measuring after collection of pollutant on the filters for the separation
of the suspended matter in fibrous or powder sorbents (Buesseler et al. 1990;
Polikarpov et al. 2008). On carrying out of investigations besides the highly
productive cylindrical winding filters, a fibrous cationite “Mtilon-T” or powder
“Anfesh”, K 4 [Fe (CN) 6 ] in the form of 15% solution, CuSO 4 in the form of 5%
solution was used. The preparation of the sorbent material was carried out through
the standard methods, the losses of cesium did not exceed 10% (Buesseler et al.
1990; Polikarpov et al. 2008). The volume of sea water was not less than
3000–5000 l. Maximum speed and the volume of the pumped water was determined
experimentally (Buesseler et al. 1990). After the ashing the samples were gone on
the gamma-spectrometric measurements. The measurements in the sorbents,
hydrobionts and bottom sediments were carried out on the scintillation NaI
(Tl) detectors (№ 1, 2) with lead shield and with the ORTEC 855 Dual Spec
AMP amplifiers, Canberra AMP 2026, and also on the end ultra-pure germanium
detector Canberra-Packard XtRa GX2019 with relative efficiency of measuring
Table 17.1 Summary data on the number of determinations of
90
Sr and
137 Cs in the objects of the
Black Sea ecosystem in the 1986–2016 yrs
Radionuclides
Objects of investigations
Region of investigations
Water
Bottom
sediments
Water
plants Mollusks
137
Cs
390
530
138
105
North-West, West and Central
regions, the coastal part of the
Crimea, range of depth of research
6–2000 m
90
Sr
1210
490
311
162
Total
1600
1020
449
267
17 Radionuclides
137
Cs and
90
Sr in Components of the Black Sea Ecosystems. . .
279
90
Sr and
137
Cs
Concentration in Natural Objects
The method of
90 Sr determination in hydrobionts, water and bottom sediments was
based on: carrying out of radiochemical procedure of the strontium
preconcentration, then purification from interfering elements, measuring of the
90
Y (the daughter product) activity on Cerenkov’s radiation and subsequent mathematical data processing (Harvey et al. 1989; Instrument description 1989,
«Quantulus 1220»). Analysis was carried out with the use of the low background
liquid-scintillation counter (LSC) LKB “Quantulus 1220”. The lower limit of
detection (LLD) was 0.01–0.04 Bq kg
À1 (for hydrobionts and bottom sediments)
and Bq m
À3 (for water samples). Recoveries are calculated from Sr-stable recovery
by flame photometry for the
90 Sr and then gravimetrically from yttrium oxalate for
90 Y (Harvey et al. 1989; Instrument description «Quantulus 1220», Polikarpov et al.
2008). Each result is reported as the mean of the values activity of parallel
repeatability samples, which were measured separately. Total relative error of the
each result does not exceed 20%.
The sorption method of determination of radioisotopes of caesium of
137 Cs in
water ecosystems is based on principle of carrying out of their gammaspectrometric measuring after collection of pollutant on the filters for the separation
of the suspended matter in fibrous or powder sorbents (Buesseler et al. 1990;
Polikarpov et al. 2008). On carrying out of investigations besides the highly
productive cylindrical winding filters, a fibrous cationite “Mtilon-T” or powder
“Anfesh”, K 4 [Fe (CN) 6 ] in the form of 15% solution, CuSO 4 in the form of 5%
solution was used. The preparation of the sorbent material was carried out through
the standard methods, the losses of cesium did not exceed 10% (Buesseler et al.
1990; Polikarpov et al. 2008). The volume of sea water was not less than
3000–5000 l. Maximum speed and the volume of the pumped water was determined
experimentally (Buesseler et al. 1990). After the ashing the samples were gone on
the gamma-spectrometric measurements. The measurements in the sorbents,
hydrobionts and bottom sediments were carried out on the scintillation NaI
(Tl) detectors (№ 1, 2) with lead shield and with the ORTEC 855 Dual Spec
AMP amplifiers, Canberra AMP 2026, and also on the end ultra-pure germanium
detector Canberra-Packard XtRa GX2019 with relative efficiency of measuring
Table 17.1 Summary data on the number of determinations of
90
Sr and
137 Cs in the objects of the
Black Sea ecosystem in the 1986–2016 yrs
Radionuclides
Objects of investigations
Region of investigations
Water
Bottom
sediments
Water
plants Mollusks
137
Cs
390
530
138
105
North-West, West and Central
regions, the coastal part of the
Crimea, range of depth of research
6–2000 m
90
Sr
1210
490
311
162
Total
1600
1020
449
267
17 Radionuclides
137
Cs and
90
Sr in Components of the Black Sea Ecosystems. . .
279