In situ experimental measurement of mercury by combining PGNAA and characteristic X-ray fluorescence

Highlights: • A PGXRF method was proposed wherein PGNAA and characteristic X-ray fluorescence are used to measure Hg. • A combined measurement experimental facility was presented. • The LOD for Hg by the combined measurement instrument was 19.4 mg kg⁻¹. In our previous research, a new detection method was proposed to measure Hg and Pb simultaneously by combining Prompt Gamma-ray Neutron Activation Analysis (PGNAA) and X-ray Fluorescence (XRF) and proved by the Monte Carlo N-Particle (MCNP) simulation code. For further experimental verification, a combined measurement experimental facility, comprising an ²⁴¹Am–Be neutron source, SAINT-GOBAIN Bismuth Germanate (BGO) as the γ-ray detector, and an NaI detector with 25 μm Be window as the X-ray detector, was presented. Specifically, the characteristic X-ray fluorescence of the Hg directly induced in this experimental facility was utilized to improve the limits of detection (LOD) of Hg instead of traditional excitation sources. The simulation and experiment results indicated that LOD for Hg by the combined measurement instrument was 19.4 mg kg⁻¹. The empirical formula of the calibration curve in this method was given based on the aforementioned calculations.