A device for reducing the atmosphere-induced interferences for analysis using inductively coupled plasma-mass spectrometry†

Abstract

The atmosphere-induced interference reduction device (AIRD) shows promise in mitigating interferences in inductively coupled plasma-mass spectrometry (ICP-MS) analysis. The effectiveness of AIRD in reducing interferences caused by atmospheric gases such as H, C, N and O was evaluated by using argon (Ar) and helium (He) as shielding gases due to their inert properties. Krypton (⁸²Kr) served as an internal standard for monitoring and correcting instrumental sensitivity drift. The shielding gas flow rate was optimized using gas dynamics simulations, revealing a threshold of 10 L min⁻¹ for optimal interference reduction. Results indicate the superiority of He in reducing interferences, with a reduction of 32% for ¹²C⁺, 51% for ¹⁵N⁺, 56% for ¹⁶O⁺, 54% for ¹⁶O¹H¹H⁺, 51% for ⁴⁰Ar¹⁴N⁺, and 42% for ⁴⁰Ar¹⁶O⁺ compared to Ar. Moreover, AIRD maintained low oxide yields even after shielding gas cessation, with oxide yield maintained at approximately 0.03% for 24 hours. Analyses of LA-ICP-MS coupled with AIRD demonstrate that ThO/Th can be reduced from 0.92% to 0.15% compared to normal analysis without AIRD. Experimental investigations further revealed that AIRD influenced elemental sensitivity, particularly with He as the shielding gas, with an ∼25.7% enhancement observed in the signal intensity of ⁸²Kr.