Boron Isotope Materials

A high variability in boron isotopic compositions of about 80 ‰ is observed in naturally occurring terrestrial materials, primarily due to the very large difference in mass between ¹⁰B and ¹¹B. For reporting δ(¹¹B), it is recommended that NIST SRM 951 boric acid be used. In comparison to average seawater, NIST SRM 951 is depleted in ¹¹B by approx. 40 ‰.

δ(¹¹B) Values of Reference Materials

Name	Material	δ_SRM951(¹¹B)
NIST SRM 951	boric acid	0 ‰ *
NIST SRM 951a	boric acid	0 ‰ *
IRMM-011	boric acid	+0.16 ‰
ERM-AE101	boric acid solution	−123.01(41) ‰
ERM-AE120	boric acid solution	−20.2(6) ‰
ERM-AE121	boric acid solution	−19.9(6) ‰
ERM-AE122	boric acid solution	−39.7(6) ‰
ERM-ED102	boron carbide	−5.0 ‰
NRC NASS-5	seawater	+39.89 ‰
OSIL IAPSO	seawater	+39.64(42) ‰
IAEA-B-1	seawater	ca. +38.7 ‰ **
IAEA-B-2	groundwater	ca. +14.1 ‰ **
IAEA-B-3	groundwater	ca. −21.1 ‰ **
IAEA-B-4	tourmaline	−8.7(2) ‰
IAEA-B-5	basalt	−3.8(2.0) ‰
IAEA-B-6	obsidian	−1.8(1.5) ‰
IAEA-B-7	limestone	+9.7(5.9) ‰
IAEA-B-8	clay	−5.1(9) ‰
NIST SRM 610	silicate glass	−0.52(53) ‰
NIST SRM 612	silicate glass	−0.51(52) ‰
GSJ JB-2	basalt rock powder	+7.24(33) ‰
GSJ JCp-1	coral powder	+24.24 ‰
NIST RM 1547	peach leaves	+41.09(1.12) ‰
NIST RM 8433	corn bran	+8.3(1.69) ‰
BCR-679	white cabbage	−23.8(1.15) ‰
Name	Material	δ_SRM951(¹¹B)

Footnotes Back to Top
* Exact value defining the δ(¹¹B) SRM951 scale.
** See the Assessment of international reference materials for isotope-ratio analysis for more details.
Values in parenthesis are expanded (k = 2) uncertainties applicable to the last digits. The values listed in this table are compilation and are not necessarily CIAAW recommendations.

Citation

W.A. Brand et al
Assessment of international reference materials for isotope-ratio analysis Pure and Applied Chemistry 86, 425-467 (2014)