Materials with known ²H, ¹³C, ¹⁵N and ¹⁸O isotopic composition

USGS24, Graphite

Unit Size: 0.5 g
Price per Unit: 130 €
Report: IAEA-TECDOC-825
Date of Release: 1995

USGS24 was prepared by T. B. Coplen, U.S. Geological Survey from Baker^®; technical grade graphite (96 percent smaller than 44 µm) [1]. Prior to splitting with a sample splitter, six spatially separated ~ 1 mg samples were analysed to verify the isotopic homogeneity of the material. Peak to peak variation was 0.11‰. The carbon stable isotopic composition was re-evaluated in a calibration exercise [2].

Analyte	Value	Unit	SD	R/I/C
δ13C	-16.049	‰VPDB	0.035	C

(R/I/C) Classification assigned to the property value for analyte (Recommended/Information/Certified)

References:

1. Gonfiantini R., Stichler W., Rozanski K. (1995): Standards and intercomparison materials distributed by the International Atomic Energy Agency for stable isotope measurements. IAEA TECDOC-825. IAEA, Vienna, 13-29.
2. Coplen T.B., Brand W.A., Gehre M., Gröning M., Meijer H.A.J., Toman B., Verkouteren R.M. (2006): New Guidelines for 13C Measurements. Anal. Chem. 78, 2439-2441.