ISO 22033:2011 PDF

Overview

ISO 22033:2011 specifies an Inductively Coupled Plasma / Atomic Emission Spectrometric (ICP‑AES) method for the determination of niobium mass fraction (0.1 % to 10 %) in nickel alloys. The standard defines sample dissolution, spectrometer performance criteria, matrix‑matched calibration and bracketing procedures to ensure accurate, interference‑minimized measurement of niobium in complex alloy matrices.

Key Topics and Requirements

• Scope: Quantitative determination of niobium in nickel alloys in the range 0.1–10 % by mass.
• Analytical principle: Dissolve a 0.25 g test portion using a mixture of HF, HCl, HNO3 and H3PO4 with perchloric‑acid fuming, add HF (and optional internal standard), dilute to 100 mL, nebulize into ICP‑AES and measure niobium emission lines.
• Calibration strategy: Close matrix‑matching of calibration solutions and bracketing (prepare two standards at ~75–95 % and 105–125 % of the estimated niobium concentration) so matrix interferences are compensated automatically. Accurate knowledge of major alloy components is required; if unknown, perform semi‑quantitative analysis first.
• Performance criteria for ICP/AES:
  • Sequential spectrometers: bandwidth (FWHM)