Double pulse spectrochemical analysis using orthogonal geometry with very low ablation energy and He ambient gas

► Double pulse LIBS is used for sensitive and quantitative analysis of Cl and Ca. ► The 2 lasers employed in orthogonal geometry and with delay of 10 μs for ablation. ► He ambient gas was used at atmospheric pressure. ► Strong Ca and Cl emissions were detected at 2.5 mJ laser energy with small crater. ► Linear calibration for Cl was obtained with detection limit of 80 ppm.