<abstract xmlns="http://www.w3.org/1999/xhtml">The sediments of two lakes located in the Baltic Uplands, the western part of the East European Plain (East Lithuania and North East Poland), were studied. Activity concentration of 210Pb was determined using two nuclear analytical techniques: determination of 210Pb in equilibrium with its beta emitting daughter 210Bi using liquid scintillation counter (LSC), and direct determination of 210Pb (and other radionuclides) by low-background gamma-ray spectrometer with a well type HPGe detector. For the 210Pb determination by LSC the methodology of lead separation based on the anion exchange resin in Cl– form (Eichrom) was used. Several steps of radiochemical procedures and respective parameters were investigated additionally. The optimized procedures for LSC method were used for case study with two lake cores. The activity concentration of 210Pb in lake sediment samples based on both nuclear analytical techniques (LSC and HPGe) were compared. 210Pb dating of cores was performed according to Constant Rate of 210Pb Supply (CRS) model with some modifications. Both techniques in the range of uncertainties gave similar results. From two considered lakes, the more eutrophic one exhibited higher sediment mass accumulation rate (MAR) values.</abstract>

The sediments of two lakes located in the Baltic Uplands, the western part of the East European Plain (East Lithuania and North East Poland), were studied. Activity concentration of 210Pb was determined using two nuclear analytical techniques: determination of 210Pb in equilibrium with its beta emitting daughter 210Bi using liquid scintillation counter (LSC), and direct determination of 210Pb (and other radionuclides) by low-background gamma-ray spectrometer with a well type HPGe detector. For the 210Pb determination by LSC the methodology of lead separation based on the anion exchange resin in Cl– form (Eichrom) was used. Several steps of radiochemical procedures and respective parameters were investigated additionally. The optimized procedures for LSC method were used for case study with two lake cores. The activity concentration of 210Pb in lake sediment samples based on both nuclear analytical techniques (LSC and HPGe) were compared. 210Pb dating of cores was performed according to Constant Rate of 210Pb Supply (CRS) model with some modifications. Both techniques in the range of uncertainties gave similar results. From two considered lakes, the more eutrophic one exhibited higher sediment mass accumulation rate (MAR) values.

Comparison of beta (LSC) and gamma (HPGe) spectrometric methods for lead-210 in chronological study

Laboratory of Nuclear Geophysics and Radioecology

Department of Geomorphology, Faculty of Geography and Regional Studies

Geochronometria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The sediments of two lakes located in the Baltic Uplands, the western part of the East European Plain (East Lithuania and North East Poland), were studied....

Core	Mass accumulation rate (g/cm²/yr)		Sedimentation rate (cm/yr)

	gamma method	gamma method	beta method	beta method
Lake Karackiai	0.009	0.008	0.14	0.12
Lake Rajgrod	0.060	0.055	0.41	0.33

Procedure	#1	#2	#3
Pb²⁺ carrier		Radiochemical yield

	72 ± 6%	77 ± 4%	76 ± 4%

Precipitates of PbSO₄ dissolved in		Solubility

	2 ml 6M ammonium acetate	2 ml 3M ammonium acetate	2 ml 0.5M EDTA/NaOH

	+	+	+

18 ml scintillation cocktailOptiphase nisaie 3		Homogeneity

	PbSO₄ in 2 ml 6M ammonium acetate	PbSO₄ in 2 ml 3M ammonium acetate	PbSO₄ in 2 ml 0.5M EDTA/NaOH

	+	+	–

²¹⁰Pb tracer		Radiochemical yield

	70 ± 5%	73 ± 8%	70 ± 6%

Comparison of beta (LSC) and gamma (HPGe) spectrometric methods for lead-210 in chronological study

Published Online: Jan 24, 2018

Page range: 34 - 43

Received: Jun 29, 2016

Accepted: Nov 20, 2017

DOI: https://doi.org/10.1515/geochr-2015-0084

Keywords
Pb, Bi, anion exchange resin, liquid scintillation counting, low-background gamma-ray spectrometry

© 2016 R. Mikalauskiene., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Sediment mass accumulation and sedimentations rates (mean values) based on 210Pbex evaluated by gamma and beta methods.

Comparison of investigated radiochemical procedures.

Comparison of beta (LSC) and gamma (HPGe) spectrometric methods for lead-210 in chronological study

Published Online: Jan 24, 2018

Page range: 34 - 43

Received: Jun 29, 2016

Accepted: Nov 20, 2017

DOI: https://doi.org/10.1515/geochr-2015-0084

KeywordsPb, Bi, anion exchange resin, liquid scintillation counting, low-background gamma-ray spectrometry

© 2016 R. Mikalauskiene., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Sediment mass accumulation and sedimentations rates (mean values) based on 210Pbex evaluated by gamma and beta methods.

Comparison of investigated radiochemical procedures.

Keywords
Pb, Bi, anion exchange resin, liquid scintillation counting, low-background gamma-ray spectrometry