Detection improvement of laser-induced breakdown spectroscopy using the flame generated from alcohol-solution mixtures

It has been proved that the detection of laser-induced breakdown spectroscopy (LIBS) could be improved by the flame. In this work, we applied flame enhanced LIBS for the detection of elements in water, while the flame was generated from the mixture of alcohol and aqueous solution. In the measurements, the flame is functioned as an assistance to enhance the LIBS detection, and also worked as a sampling way for the solution. The obtained results indicate that the detection of manganese, calcium, lithium and magnesium were significantly improved by the proposed method. It is found that the flame actually forms an environment for the laser-induced plasma to have higher temperature and lower electron density, as comparing with the plasma underwater. With the method, the quantitative analysis was tried out for the element of manganese, and the internal reference of calcium was used. It is interesting to find that, when mixing with the calcium, the minimum detectable concentration of manganese could be lowered and the intensity was greatly increased. According to the result, it is suggested that the proposed method might be a practical way for liquid detection of LIBS because of the simplicity and the effectiveness.