Development of methodology for the determination of boron in ThO2 employing spectrophotometry

Boron was determined in ThO₂ employing spectrophotometry using curcumin as complexing agent after dissolution with 85 % ortho phosphoric acid and separation of boron with 10 % 2-ethyl hexane 1,3 diol in CHCl₃. The methodology was validated by employing ThO₂ standards made from inter laboratory comparison experiments DAE, India. Absolute detection limit of the methodology was found to be 30 ng. Precision and accuracy of the methodology were found to be 4.2 and 2 % respectively. The expanded uncertainty in measurement of boron (at coverage factor 2) was estimated as per ISO guidelines employing bottom-up approach and it was found to be 9.2 %.