Determination of Magnesium and Sodium in Brine by Filter Paper Adsorption Laser-Induced Breakdown Spectroscopy

To make better use of brine, it is necessary to detect the element content before mining and processing. Laser-induced breakdown spectroscopy (LIBS) is a fast, simple, and flexible analytical method. However, the absorption of laser energy by liquid greatly reduces the plasma life and emission intensity. Although an improvement in the excitation source improves the characterization of the liquid, it makes the device more complicated and increases the cost. This article introduces a method for detecting Na and Mg in brine using LIBS with filter paper adsorption (FPA-LIBS). The limits of detection were 7.98 and 10.57 mg L-1 for sodium (Na) and magnesium (Mg), respectively. The results of six brine samples obtained using this method and inductively coupled plasma - optical emission spectrometry were compared. The discrepancy and recovery values were 1.34-8.94% and 91.64-107.35%, respectively. In addition, the results of the analysis after storage for five days were consistent with those measured initially. These results indicate that FPA-LIBS accurately determined Na and Mg in brine.