作　　者： ; ;

机构地区： 华南理工大学电力学院

出　　处： 《强激光与粒子束》 2011年第2期293-297,共5页

摘　　要： 将激光诱导击穿光谱技术(LIBS)应用于复混肥中的主要营养元素之一钾(K)元素的含量检测。样品中K养分的浓度较高,在等离子体形成过程中容易发生自吸收。通过分析谱线的激发能级、跃迁几率以及自吸收程度,确定最佳分析谱线为钾的原子线404.40 nm。同时为了提高LIBS分析复合肥样品的测量精度,分析了光谱测量稳定性随谱线信号平均次数的变化规律。结果显示,在本实验条件下,一次测量平均100个脉冲所得的光谱信号,其相对标准偏差较小。实验总共分析了9个复合肥样品,其中7个作为定标样品,建立K养分浓度的定标曲线,另外2个作为未知样品,用以检验LIBS分析K养分浓度的测量精确度。研究结果表明,定标曲线的线性拟合度为0.989,检验样品的绝对误差小于0.3%,体现了激光诱导击穿光谱技术快速分析复混肥中钾养分的潜力。 Laser induced breakdown spectroscopy（LIBS） has been used to analyze the concentration of potassium in compound fertilizer.Self-absorption was prone to appear in the formation process of plasma because of the high-content potassium in samples.The atomic spectral line 404.40 nm of potassium was determined as the optimized line by analyzing the excitation energy,transition probability and self-absorption of spectral lines.Experimental stability with different average numbers of pulses was discussed,and the results indicated that the average measurement of 100 pulses had a lower relative standard deviation.Nine samples were analyzed and seven of them were tested to establish the calibration curve of measured concentration of K2O.The linear fitting degree of the calibration curve was 0.989 and the measured concentration of K2O in the other two samples was well consistent with the corresponding reference concentration with an absolute error of less than 0.3%.

关 键 词： 激光诱导击穿光谱 复混肥 钾含量 自吸收 定量分析

领　　域： [理学] [理学]