Nakamura S, Ito Y, Sone K, Hiraga H, Kaneko K
Department of Mechanical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-21, Japan.
Anal Chem. 1996 Sep 1;68(17):2981-6. doi: 10.1021/ac9601167.
We have applied laser-induced breakdown spectroscopy to quantitative analysis of colloidal and particulate iron in water. A coaxial sample flow apparatus developed in our previous work, which allowed us to control the atmosphere of laser-induced plasma, was used. Using sequential laser pulses from two Q-switched Nd:YAG lasers as excitation sources, the FeO(OH) concentration in the tens of ppb range was determined with an optimum interval between two laser pulses and an optimum delay time of a detector gate from the second pulse. The detection limit of Fe decreased substantially using two sequential laser pulse excitations: the 0.6 ppm limit of single pulse excitation to 16 ppb with sequential pulse excitation. The effects of the second laser pulse on the plasma emission were studied. The concentration of iron in fine particles in boiler water sampled from a commercially operated thermal power plant has been determined successfully by this method. The results show the capability of laser-induced breakdown spectroscopy in determining suspended colloidal and particulate impurities in a simple and quick way.
我们已将激光诱导击穿光谱技术应用于水中胶体铁和颗粒铁的定量分析。使用了我们之前工作中开发的同轴样品流动装置，该装置使我们能够控制激光诱导等离子体的气氛。以两台调Q Nd:YAG激光器的序列激光脉冲作为激发源，通过两个激光脉冲之间的最佳间隔以及探测器门相对于第二个脉冲的最佳延迟时间，测定了数十ppb范围内的FeO(OH)浓度。使用两个序列激光脉冲激发时，铁的检测限大幅降低：单脉冲激发的检测限为0.6 ppm，而序列脉冲激发的检测限为16 ppb。研究了第二个激光脉冲对等离子体发射的影响。通过该方法成功测定了从一家商业运营的热电厂采集的锅炉水中细颗粒中铁的浓度。结果表明激光诱导击穿光谱技术能够以简单快速的方式测定悬浮的胶体和颗粒杂质。
