Fast Determination of Gas Evolution Volume of Calcium Carbide by Laser-induced Breakdown Spectroscopy

Calcium carbide is an important chemical raw material, and its gas evolution volume is a crucial indicator for its quality. However, the traditional methods to determine the gas evolution volume are costly and complicated. More important, it cannot be quantitatively detected with an in-situ real-time way. Herein, a totally new method to measure the gas evolution volume of calcium carbide based on Laser-induced breakdown spectroscopy (LIBS) is proposed for the first time. Tableting and pre-pulse were used to reduce the matrix effect. Moreover, the spectral pretreatments and standardization are necessary, including the removal of abnormal spectra, fitting and correction of background baselines and optimization of characteristic spectral line. Eventually, based on the principal component analysis combined with partial least squares method (PCA-PLS), a prediction model was successfully established, with the root mean square error of prediction set (RMSEP) of 1.498 L/kg. The average relative error of prediction set (AREP) is 0.48%. Our result illustrates that the LIBS provides a new solution for the rapid, accurate, and safe determination of gas evolution volume of calcium carbide.