Determination of boron in Zr–Nb alloys by glow discharge quadrupole mass spectrometry Raparthi Shekhar a , J. Arunachalam a, * , G. Radha Krishna b , H.R. Ravindra b , B. Gopalan b a National Centre for Compositional Characterisation of Materials Bhabha Atomic Research Centre, ECIL Post, Hyderabad 500062, India b Control Laboratory, Nuclear Fuel Complex, ECIL Post, Hyderabad 500062, India Received 22 April 2004; accepted 17 December 2004 Abstract Direct determination of boron in Zr–2.5%Nb, Zr–1%Nb alloys and zirconium metals which are extensively used as structural materials in nuclear reactors has been carried out by glow discharge quadrupole mass spectrometer (GD- QMS). Relative sensitive factor (RSF) values for boron were determined using different solid standard reference mate- rials (Zircaloy and steel). A comparison of the GD-QMS results obtained using these RSF values, with DC–Arc-AES (direct current arc atomic emission spectrometry)/certified values showed reasonably good agreement in all the Zr-based materials analysed for boron in the range of 0.1–7 mg kg 1 . Quantitation of boron in Zr matrix is possible even with a steel standard when certified for Zr and B. Internal precision (intra-sample precision) was found to be typically ±4% RSD (relative standard deviation) and the inter-sample precision was ±10% RSD for boron at 0.1 mg kg 1 levels. The overall accuracy of the procedure was found to be ±8% at 0.5 mg kg 1 levels of boron using Zircaloy and steel standards. Under optimised experimental conditions the detection limit for boron was found to be ±13 lg kg 1 . Ó 2005 Elsevier B.V. All rights reserved. 1. Introduction Zr–Nb alloys with varying niobium compositions find extensive applications in nuclear technology due to their excellent corrosion resistant properties and higher mechanical strength than conventional and ter- nary zirconium alloys [1]. While the Zr–2.5% Nb alloy is used as a structural material for pressure tubes of CANDU-pressurised heavy water reactors, Zr–1%Nb is used as a fuel cladding material in pressurised water reac- tors. In view of its important applications, characterisa- tion for chemical purity with respect to many critical trace impurities (B, Hf, Cd, etc.) assumes importance. Boron, being a strong neutron absorber, has to be accu- rately determined at trace levels in various process inter- mediates like arc melted ingots and final products. The maximum permissible limit for boron in these alloys is 0.5 mg kg 1 . Determination of boron at trace and ultra trace levels is carried out by either wet chemical procedures using inductively coupled plasma atomic emission spec- trometry (ICP-AES), inductively coupled plasma mass 0022-3115/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jnucmat.2004.12.010 * Corresponding author. E-mail address: aruncccm@rediffmail.com (J. Arunacha- lam). Journal of Nuclear Materials 340 (2005) 284–290 www.elsevier.com/locate/jnucmat