The present study reports developing a bench-top Laser-Induced Breakdown Spectroscopy (LIBS) set up for the online analysis of powder samples without sample preparation. The powder particle blow-off during pulsed laser ablation was mitigated by adding blow gas (an inert gas blown across the ablation surface) and a suction unit (for extraction of gas and plume and blow-off particle) to the existing LIBS setup. The influence of a blow-gas combined with a suction unit on LIBS emission intensity from coal powder and flyash particles is studied in the present work. The effect of the blow gas flow rate and the suction pressure was studied on the LI-BS emission intensity and removal of the laser blown-off particle cloud. The combination gas flow at 2 lpm (liter per minute) flow rate and suction at 925 mbar (absolute) show an increase in the LIBS emission intensity and effective particle removal. The ratio of LIBS emission intensity of the powder sample and solid-target (pellet) sample improved from 0.25 without the Ar gas flow and the suction unit to 0.85, which is by a factor of 3.4 times the proposed approach.

本研究报告开发了一种台式激光诱导击穿光谱仪（LIBS），该系统可用于无需样品制备的粉末样品在线分析。通过在现有的LIBS装置中增加吹气（吹扫整个消融表面的惰性气体）和吸气单元（用于抽出气体，烟羽和吹散颗粒），可以减轻脉冲激光烧蚀过程中的粉末颗粒吹散。在本工作中，研究了吹气与吸气单元的组合对煤粉和飞灰颗粒中LIBS排放强度的影响。研究了吹气流量和吸气压力对LI-BS发射强度和激光吹出颗粒云的去除的影响。流量为2 lpm（升/分钟）和925 mbar（绝对值）的吸气相结合，显示LIBS发射强度的增加和有效的颗粒去除。粉末样品和固体目标（小丸）样品的LIBS发射强度之比从0.25（无Ar气体流和抽吸装置的情况下）提高到0.85，是提出方法的3.4倍。