Eighteen international reference standards, mostly geochemical standards, have been analysed for boron using prompt‐gamma neutron activation analysis (PGNAA). There is good agreement between the results for samples with high boron abundances and the few published values using PGNAA and other methods. However, correlation is poor at low boron abundances, especially in those standards with low boron/sodium ratios. Corrections for sodium interference on boron have been critically evaluated and the data corrected using two different method