A new approach for baseline correction in laser induced breakdown spectroscopy

Laser-induced breakdown spectroscopy is a promising technique in ocean applications due to its great capability of in situ detection. However, LIBS detection is not satisfactory in water, and a typical performance is that emission lines usually overlap with the high spectral background. So, it is necessary to correct the baseline (i.e. spectral background) in signal processing to obtain better signals for quantitative or qualitative analysis. In this work, we developed a new method (WASS: wavelength artificial shift subtraction) to remove the spectral background for underwater detection of LIBS. The method is easy to conduct by making a wavelength shift on a single spectrum. After conducting a subtraction between shifted- and unshifted spectra, the high baseline of the LIBS signal could be well corrected, especially for weak signals. Moreover, signal fluctuation was significantly decreased, and a fine quantitative analysis could be established with a low standard deviation. The obtained results suggested that the method was effective in baseline correction for signal extraction, and it might be a practical way for LIBS quantitation in the future.