Fig. 1. Schematic diagram of LIBSOPA system

Fig. 2. Schematic diagram of the sample

Fig. 3. Relationship between spot size and spectral signal intensity

Fig. 4. Relationship between spot size and spectral signal stability

Fig. 5. Relationship between ablation pulses and spectral signal intensity

Fig. 6. Relationship between ablation pulses and spectral signal stability

Fig. 7. Calibration curve

Fig. 8. Actual sample and scanning mode

Fig. 9. Two-dimensional component distribution map of carbon-LIBSOPA

Fig. 10. Schematic diagram of sampling for HF-IR absorption method

Fig. 11. Comparison of the carbon concent in different regions with two test methods

Fig. 12. Two-dimensional component distribution maps-LIBSOPA

Fig. 13. Two-dimensional component distribution maps-microbeam X-ray fluorescence spectrometry