Laser-induced breakdown spectroscopy(LIBS) is an atomic emission spectrum technique. Its basic principle is to use strong pulsed laser to ablate and excite the surface of sample to be plasma, then the plasma emission spectrum can be recorded by spectrometer and CCD. The information of composition and concentrations of elements in the material can be obtained through the spectrum analysis. LIBS technology is referred to as the future star of chemical analysis because of its advantages, such as fast detection, no need of sample pretreatment, simultaneous measurement of various elements, and adaptability to various sample state including solid, liquid and gas. It has great application potential on the realization of in-situ detection of aerosols.

As a very convenient technique, laser-induced breakdown spectroscopy (LIBS) has been used for in-situ and on-line analysis of aerosol by many researchers. The research profiles and progress of LIBS used for aerosol analysis in recent years are briefly reviewed. The principle and features of LIBS analysis are described. Factors that influence the LIBS for aerosol detection are analyzed. The experiments about LIBS analysis for aerosols are summarized. LIBS applications in the region of atmospheric environment and industrial processes are also introduced.

A laser induced breakdown spectroscopy analytical system was established by using a pulsed 1064 nm Nd:YAG laser and a portable fiber optical spectrometer. The emitted spectra of the laser induced soil plasma were recorded along with the variation of experimental parameters. By using the AlⅡ 422.68 nm as the analysis line, the effects of the laser energy and data acquisition delay time on the spectrum characterizations of soil plasma emission were investigated in detail. Generally, at a fixed laser energy, the signal intensity, background and noise of the spectrum decrease with a longer acquisition time delay, while the signal to noise ratio (SNR) first increases to a maximum and then decreases. And at a fixed data acquisition time delay, the signal intensity and noise of the spectrum increase with the increase of laser energy, but the background and SNR first increase to a maximum and then decrease. For specific laser energy, the SNR can be optimized at a selected suitable data acquisition time delay, and the optimal time delay will increase with increased laser energy. Based on the combination effects of laser energy and data acquisition time delay, the optimized parameters of the system are 120 mJ for the laser energy and 1.5 μs for the acquisition delay time.

Laser-induced breakdown spectroscopy (LIBS) technique is widely used to analyze the composition and the concentration of elements in materials, which is based on the atomic emission spectral technology. LIBS has excellent advantages, such as rapid speed, multi-element detection and no need of any sample pretreatment. A lot of researches are done in the fields of the environment monitoring, industrial production control, food security and so on, and a relatively complete theory system has been formed. There still are a lot of technical problems along with the instrument development of LIBS technology. A review is given about the mechanism of LIBS technique and the progress of LIBS technology. The spectral detection method, qualitative detection of the characteristic emission lines and quantitative detection of heavy metal elements are included in the LIBS detection process. In addition, the instrument development of LIBS technology and inquiries about the developing prospect of LIBS instruments are described. The challenges and developing prospect of LIBS are investigated at last.

In order to determine the optimal detection time of laser-induced breakdown spectroscopy(LIBS), time-resolved LIBS technique has been adopted to study the decay characteristics of peak intensity and spectral intensity of four elements Fe, Pb, Ca and Mg contained in the sample. The extreme value of ratio of peak intensity of characteristic lines and spectral intensity of continuous radiation is calculated, and the calculation value of time corresponding to the optimal signal-to-background ratio (SBR) of characteristic lines is obtained. The peak intensity of characteristic lines and spectral intensity of continuous radiation both decay in exponential form, the decay time of four characteristic lines are 1.42, 1.95, 1.69, 1.65 μs, and the corresponding decay time of continuous radiation are 0.85, 0.93, 0.89, 0.87 μs respectively. The calculation value of corresponding time of optimal SBR of four characteristic lines are 1.43, 1.77, 1.62, 1.80 μs, and experimental measurement value of corresponding time of optimal SBR are 1.5, 2.0, 1.5, 1.5 μs. They have a good consistency. The corresponding time of optimal SBR can be predicted by evolution law of peak intensity of characteristic lines and spectral intensity of continuous radiation. The results indicate that the optimal detection time of LIBS is closely related to decay law of continuous radiation and characteristic lines, and the corresponding time of optimal SBR of spectral lines can be predicted by evaluating extreme value of the ratio of spectral intensity. The method provides the basis for selecting the optimal time of LIBS detection and analysis.

Laser-induced breakdown spectroscopy (LIBS) has the benefits of simultaneous multi-element detection capability, online/in-situ measurement capability without physical intervention and being regarded as a versatile analytical technique for gases, liquids, solids and aerosols. Thus, LIBS has the potential of application in the multiple environmental monitoring fields like air, water and soil monitoring. As to different samples, the developments of sample preparing, experimental setup, data processing and the figure of merit, were reviewed based on researches of these years. The application status and future developments were also summarized.

The spatial distribution characteristics of aerosol optical depth (AOD) over Jiangxi were analyzed by using long-term (2007～2014)MODIS/Terra AOD products. It is found that the average AOD varies greatly with locations and presents the increase trend from the south to the north. Among these cities, Nanchang and Jiujiang take the first place in terms of AOD value. At the same time, the mixture status of aerosol layer and cloud layer and the separated status were obtained based on CALIPSO/CALIOP vertical feature mask(VFM) data. Furthermore, the height resolved probability distributions of aerosol and its subtypes, as well as cloud, were calculated. More importantly, maximum probability height (MPH) of aerosol and cloud layers was figured out over Jiangxi Province and the surrounding region. Results indicated that aerosol particles mainly located at vertical levels of 1～3.5 km, and the occurrence frequency of mixture status of aerosol and cloud layers is much higher than that of separated status. During levels between 2～4 km, the highest occurrence frequency of “polluted dust” is in spring, followed by winter, and then summer and autumn. By contrast, the occurrence frequency of “smoke” aerosol is highest in summer, followed sequentially by spring, winter, and autumn. The MPH values of aerosol and cloud, based on nighttime CALIOP data, exhibit large seasonal variation.