Application report

Accuracy and precision of CN isotope measurements AB-I-181114-E-01 using the BiovisION, EcovisION and GeovisION

EA-IRMS systems are commonly used to determine the and stable isotope ratio of different materials. Through quantitative high temperature decomposition, the elemental analyser (EA) converts the sample into its gaseous components and determines the elemental composition quantitatively. Subsequently, the isotopic ratio of the single components is analysed by the isotope ratio mass spectrometer (IRMS). Elementar group provides comprehensive systems with EA, IRMS, and dedicated software for routine isotope ratio analyses: BiovisION, EcovisION and GeovisION. This report shows the excellent performance of all visION systems in CN mode by analyses of different primary, secondary and working standards with known isotopic composition.

Analyses Different standard materials are weighed into tin boats with a sample weight ranging between 0.3 and 1 mg. All samples are analysed on the BiovisION in CN mode (vario ISOTOPE + visION). For samples with a high carbon content, the sample flow is diluted beforeδ 13C analysis in the mass spectrometer. International isotope standards are used to calibrate the EA-IRMS system.

Figure 1. δ15N and δ13C isotope ratio of different standard materials (see Table 1). The theoretical and measured isotope ratio show a very good correlation (r >> 0.99).

Elementar Analysensysteme GmbH phone: +49 6181 9100-0 Donaustraße 7 email: [email protected] 63452 , web: www.elementar.de 1

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Accuracy and precision of CN isotope measurements AB-I-181114-E-01 using the BiovisION, EcovisION and GeovisION

Table 1. Analysis of the δ15N and δ13C isotope ratios of different standard materials using the BiovisION. A two point calibration is applied to the EA-IRMS system, using USGS-25 and USGS-26 to calibrate the δ15N values, and USGS-41 and caffeine#1 to calibrateδ 13C.

15 15 13 13 Sample δ N [‰AIR] theory δ N [‰AIR] analysis δ C [‰VPDB] theory δ C [‰VPDB] analysis

USGS-25 -30.4 ± 0.4 -30.40 ± 0.04* - -

USGS-26 53.7 ± 0.4 53.70 ± 0.05* - -

USGS-41 47.6 ± 0.2 47.56 ± 0.03 37.63 ± 0.049 37.63 ± 0.02*

IAEA-N2 20.3 ± 0.2 20.33 ± 0.07 - -

IAEA-600 1.0 ± 0.2 0.99 ± 0.02 -27.8 ± 0.043 -27.75 ±0.04

Caffeine#1 -2.9 ± 0.03 -2.92 ± 0.01 -35.05 ± 0.02 -35.05 ± 0.05*

Acetanilide#2 19.56 ± 0.01 19.66 ± 0.05 -29.5 ± 0.03 -29.40 ± 0.09

Urea#2 20.17 ± 0.06 20.19 ± 0.03 -8.02 ± 0.05 -8.20 ± 0.03

Casein York 6.56 ± 0.17 6.38 ± 0.03 -23.72 ± 0.01 -23.42 ± 0.05

Casein Spain 4.7 ± 0.12 4.6 ± 0.04 -22.4 ± 0.04 -22.14 ± 0.06

Acetanilide 1.51 ± 0.08 1.55 ± 0.02 -27.57 ± 0.03 -27.48 ± 0.05

Sulfanilic acid -1.67 ± 0.08 -1.75 ± 0.02 -28.44 ± 0.09 -28.19 ± 0.05

Glutamic acid -4.12 ± 0.03 -4.08 ± 0.02 -28.6 ± 0.08 -28.4 ± 0.04

Urea -1.11 -1.13 ± 0.01 -45.99 -45.58 ± 0.16

NH4Cl -1.03 -1.05 ± 0.02 - -

NaNO3 16.28 16.33 ± 0.20 - - * used for calibration of the EA-IRMS.

For the analysis the average and standard deviation of four replicates is given, for the interna- tional standards the isotope ratio and standard deviation of the certificate and for the lab stand- ards the average and standard deviation of several measurements over a time period of 2 years.

Elementar Analysensysteme GmbH phone: +49 6181 9100-0 Donaustraße 7 email: [email protected] 63452 Hanau, Germany web: www.elementar.de 2

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Accuracy and precision of CN isotope measurements AB-I-181114-E-01 using the BiovisION, EcovisION and GeovisION

Results The isotope ratios analysed with the visION and the corresponding theoretical values are shown in Table 1 and Figure 1. The results show that the δ15N and δ13C isotope ratios of all standard materials could be determined with a very high precision and accuracy. The standard deviation of four replicate analyses is well below 0.1 ‰ for most substances. The isotope ratios analysed on the visION show an excellent agreement with their nominal values.

The data demonstrate that analytical performance and reliability combine in the new visION systems, resulting in excellent analytical accuracy and unprecedented user-friendlyness.

Elementar Analysensysteme GmbH phone: +49 6181 9100-0 Donaustraße 7 email: [email protected] 63452 Hanau, Germany web: www.elementar.de 3

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