Stable Isotope Laboratory

METHOD DESCRIPTION

KIEL IV Carbonate Device

Oxygen and carbon isotopes in carbonates

Stable isotopic composition of oxygen and carbon in carbonates is determined using a Thermo KIEL IV Carbonate Device connected to a Finnigan Delta Plus isotope ratio mass spectrometer in a Dual Inlet system. CO_{2} is extracted from carbonates using the method described by McCrea (1950). Sample (minimum weight 20 µg) is reacted with orthophosphoric acid (density 1.94 g/dm^{3}) at 70 °C. International standard NBS 19 is analyzed per every ten samples. Isotope ratios are reported as delta (δ) values and expressed relative to VPDB standard.

Measurement precision:

Standard deviation (1σ) δ^{13}C ± 0.03‰

Standard deviation (1σ) δ^{18}O ± 0.07‰

McCrea, J.M. (1950): The isotopic chemistry of carbonates and a paleo-temperature scale. J. Chem. Phys. 18: 849-857.

Measurement precision:

Standard deviation (1σ) δ

Standard deviation (1σ) δ

McCrea, J.M. (1950): The isotopic chemistry of carbonates and a paleo-temperature scale. J. Chem. Phys. 18: 849-857.

Flash EA 1112HT

Nitrogen and carbon isotopes in organic and inorganic solid samples

Stable isotopic composition of nitrogen and carbon is determined using a Thermo Flash EA 1112HT elemental analyzer connected to a Thermo Delta V Advantage isotope ratio mass spectrometer in a Continuous Flow system. Minimal weight of samples depends on the wt% amount of both elements. Samples wrapped in tin capsules are combusted at 1020 °C. Released gases (CO_{2} and N_{2} ) split in a GC column are transferred to MS source through a capillary. Isotope ratios are reported as delta (δ) values and expressed relative to VPDB for δ^{13}C and to atmospheric nitrogen for δ^{15}N. Delta values are normalized to a calibration curve based on international standards USGS 40, USGS 41, IAEA 600.

Measurement precision:

Standard deviation (1σ) δ^{13}C ± 0.33‰

Standard deviation (1σ) δ^{15}N ± 0.43‰

Measurement precision:

Standard deviation (1σ) δ

Standard deviation (1σ) δ

Oxygen isotopes in phosphates

Stable isotope composition of oxygen in phosphates is determined using a Thermo Flash EA 1112HT elemental analyzer connected to a Thermo Delta V Advantage isotope ratio mass spectrometer in a Continuous Flow system. The minimal weight of sample is ca. 400 µg. Samples wrapped in silver capsules are pyrolyzed at 1450 °C. Released gas (CO) is transferred to MS source through a capillary. Isotope ratios are reported as delta (δ) values and expressed relative to VSMOW. Delta values are normalized to a calibration curve based on internal standards UMCS 1, UMCS 2 and international standard B 2207.

Measurement precision:

Standard deviation (1σ) δ^{18}O ± 0.3‰

Measurement precision:

Standard deviation (1σ) δ

Sulfur isotopes in sulfates

Stable isotopic composition of sulfur in sulfates is determined using a Thermo Flash EA 1112HT elemental analyzer connected to a Thermo Delta V Advantage isotope ratio mass spectrometer in a Continuous Flow system. The minimal weight of sample is ca. 400 µg plus 10-fold quantity of V_{2}O_{5}. Samples wrapped in tin capsules are combusted at 1020 °C. Released gas (SO_{2}) is transferred to MS source through a capillary. Isotope ratio is reported as delta (δ) values and expressed relative to VCDT. Delta values are normalized to a calibration curve based on international standards NBS 127, IAEA SO-5, IAEA SO-6.

Measurement precision:

Standard deviation (1σ) δ^{34}S ± 0.3‰

Measurement precision:

Standard deviation (1σ) δ

Oxygen isotopes in sulfates

Stable isotopic composition of oxygen in sulfates is determined using a Thermo Flash EA 1112HT elemental analyzer connected to a Thermo Delta V Advantage isotope ratio mass spectrometer in a Continuous Flow system. The minimal weight of sample is ca. 400 µg. Samples wrapped in silver capsules are pyrolyzed at 1450 °C. Released gas (CO) is transferred to MS source through a capillary. Isotope ratios are reported as delta (δ) values and expressed relative to VSMOW. Delta values are normalized to a calibration curve based on international standards NBS 127, IAEA SO-5, IAEA SO-6.

Measurement precision:

Standard deviation (1σ) δ^{18}O ± 0.5‰

Measurement precision:

Standard deviation (1σ) δ

Sulfur isotopes in sulfides

Stable isotopic composition of sulfur in sulfides is determined using a Thermo Flash EA 1112HT elemental analyzer connected to a Thermo Delta V Advantage isotope ratio mass spectrometer in a Continuous Flow system. The minimal weight of sample is ca. 400 µg plus 10-fold quantity of V_{2}O_{5}. Samples wrapped in tin capsules are combusted at 1020 °C. Released gas (SO_{2}) is transferred to MS source through a capillary. Isotope ratios are reported as delta (δ) values and expressed relative to VCDT. Delta values are normalized to a calibration curve based on international standards IAEA S-1, IAEA S-2, IAEA S-3.

Measurement precision:

Standard deviation (1σ) δ^{34}S ± 0.2‰

Measurement precision:

Standard deviation (1σ) δ

GasBench II

Isotopic composition of Dissolved Inorganic Carbon in water

Stable isotopic composition of Dissolved Inorganic Carbon in water is determined using a Thermo GasBench II connected to a Thermo MAT 253 isotope ratio mass spectrometer in a Continuous Flow system. 0,8 ml of sample is equilibrated during 18 hours at 70 °C prior to analysis. Isotope ratios are reported as delta (δ) values and expressed relative to VPDB for δ^{13}C. Delta values are normalized to a calibration curve based on international standards NBS 19, NBS 18, LSVEC.

Measurement precision:

Standard deviation (1σ) δ^{13}C ± 0.2‰

Measurement precision:

Standard deviation (1σ) δ

Oxygen isotopes in water

Isotopic composition of oxygen in water is determined using a Thermo GasBench II connected to a Thermo MAT 253 isotope ratio mass spectrometer in a Continuous Flow system. 0.5 ml of sample is equilibrated during 18 hours at 32 °C prior to analysis. Isotope ratios are reported as delta (δ) values and expressed relative to VSMOW for δ^{18}O. Delta values are normalized to a calibration curve based on standards GISP, W6444, W 67400.

Measurement precision:

Standard deviation (1σ) δ^{18}O ± 0.25‰

Measurement precision:

Standard deviation (1σ) δ

HDevice

Hydrogen isotopes in water

Stable isotopic composition of hydrogen in water is determined using a Thermo HDevice connected to a Thermo MAT 253 isotope ratio mass spectrometer in a Dual Inlet system. 1,2 µl of sample is reduced in chromium reactor at 850 °C prior to analysis. Isotope ratios are reported as delta (δ) values and expressed relative to VSMOW for δ^{2}H. Delta values are normalized to a calibration curve based on standards GISP, W6444, W 67400. H3+ factor is determined every sequence run.

Measurement precision:

Standard deviation (1σ) δ^{2}H ± 1‰

Measurement precision:

Standard deviation (1σ) δ

ORTEC Octete PC Alpha spectrometer

U-Th dating

Uranium and thorium activities are determined using an alpha spectrometer OCTETE-PC, ORTEC. The minimum weight of samples depends on uranium concentration. After chemical treatment, uranium and thorium are separated on chromatographic column filled with Dowex 1x8. Subsequently, the samples are electrodeposited on steel disk prior to the measurements. The age of samples is calibrated based on isotope ratios of ^{234}U/^{238}U, ^{230}Th/^{234}U, ^{230}Th/^{232}Th and uranium concentration (ppm). The maximum age range of the method is ca. 350 thousand years.

Ultra Low Level Liquid Scintillation β/α Spectrometer Quantulus 1220

Tritium activity in water

Tritium activity in water is determined using an QUANTULUS 1220 ultra-low level LSC-liquid scintillation counter. 0.5 l of sample is pre-distilled and after that 300 ml of each sample undergoes electrolytic enrichment in stable conditions (temperature 2 °C, current intensity 5.5 A) until the sample volume is reduced to 15 ml. Subsequently the sample is distilled and mixed with an Ultima Gold

Measurement precision: 0.15 TU.

Gamma Spectrometer Be 5030

Short-lived isotope activity in solid samples

Short-lived isotope activity measurement is determined using gamma spectrometer Be 5030 with a low background shield of measurement chamber. ^{210}Pb and ^{137}Cs are analyzed in various kinds of samples, e.g. lake sediments, soil and peat. Sample is homogenized and dried at 60 °C until attains stable mass prior to analysis. Weight of sample is 2-3 grams. Data is calibrated using a GENIE 2000 and reported as Bq/kg units.

Elemental analyzer Vario MicroCUBE

Percent amount of nitrogen, hydrogen, carbon and sulfur in solid samples

Percent amount of nitrogen, hydrogen, carbon and sulfur is determined using a Vario MicroCUBE elemental analyzer. Minimal weight of sample depends on the wt% of every element. Samples wrapped in tin capsules are combusted at 1150 °C. Released gases (CO_{2}, N_{2}, H_{2}O and SO_{2}) are separated on GC column and determined by thermal conductivity detector. Percent amount values are normalized to a sulfanilic acid standard. Measurement results are reported as wt%.

Measurement precision:

Standard deviation (1σ) %C ± 0.6‰

Standard deviation (1σ) %N ± 0.18‰

Standard deviation (1σ) %H ± 0.21‰

Standard deviation (1σ) %S ± 0.43‰

Detection limit is 40 ppm for every element.

Measurement precision:

Standard deviation (1σ) %C ± 0.6‰

Standard deviation (1σ) %N ± 0.18‰

Standard deviation (1σ) %H ± 0.21‰

Standard deviation (1σ) %S ± 0.43‰

Detection limit is 40 ppm for every element.