Calibration free laser ablation molecular isotopic spectrometry (CF-LAMIS) for boron isotopic composition determination

Abstract

A calibration free laser ablation molecular isotopic spectrometry (CF-LAMIS) approach for boron isotopic concentration determination has been investigated under ambient atmospheric air conditions. Using non-rigid rotor and anharmonic equations and diatomic constants, a database for ro-vibrational transitions of both the ¹¹BO B-X band and the ¹⁰BO B-X band was developed. The selected molecular transition of boron oxide (BO) was computed using this database. The computed molecular transitions combined with an in-house developed molecular spectrum fitting algorithm based on Born–Oppenheimer approximation and Boltzmann equilibrium provides compositional information from an experimental spectrum. The parameters such as laser energy, acquisition delay time and spectral wavelength with respect to the degree of differentiability are optimized to predict the result. This CF-LAMIS method predicts the ¹⁰B isotopic concentration with an accuracy and % RSD of 1.1% and 2.7%. The method introduces a new outlook to calibration-free analytical analysis, as boron isotopic concentrations were predicted accurately and precisely under ambient air conditions without any standard samples.