CBET-1: Certified Reference Material of carbon-13 labelled arsenobetaine bromide

The following tables show those constituents for which certified and information values have been established for this [13CO]-arsenobetaine bromide purity certified reference material (CRM).

The certified value shows the purity of [13CO]-arsenobetaine bromide. Certified values are based on results from data generated at NRC using quantitative proton nuclear magnetic resonance spectroscopy (1H-qNMR) and chemical specifications. The expanded uncertainty (UCRM) in the certified value is equal to U = kuc where uc is the combined standard uncertainty calculated according to the JCGM Guide [1] and k is the coverage factor. A coverage factor of two (2) was applied. It is intended that UCRM accounts for every aspect that reasonably contributes to the uncertainty of the measurement.

Table 1: Certified quantity values for CBET-1

Substance Molecular formula Mass fraction,
[13CO]-arsenobetaine bromide (a) 13C1C4H12AsO2Br 0.9918 ± 0.0050
[13CO]-arsenobetaine (cation) (a) 13C1C4H12AsO2+ 0.6870 ± 0.0034

Table 2: Reference value for impurities in CBET-1

Substance Molecular formula Mass fraction,
ethanol (a) C2H6O 0.0027 ± 0.0008


The coding refers to the instrumental method of analyte determination.

  • a - Proton nuclear magnetic resonance spectroscopy (1H-qNMR)

Intended use

This reference material is primarily intended for use in the calibration of procedures and the development of methods for the determination of arsenobetaine. A minimum sample mass of 25 mg is recommended.


Included in the combined uncertainty estimate (uc) are uncertainties in the batch characterization (uchar), uncertainties related to possible between-bottle variation (uhom) and uncertainties related to inconsistency between the various measurement methods (umethod). Expressed as standard uncertainties, these components are listed in Table 3 [3].

Table 3: Uncertainty Components for CBET-1

Substance uc,
[13CO]-arsenobetaine bromide 0.0025 0.0019 0.0015 0.0008
[13CO]-arsenobetaine (cation) 0.0017 0.0013 0.0010 0.0006
ethanol 0.0004 0.0001 0.0003 0.0003

Date of issue: February 2016
Date of expiry: February 2026

Date modified: