激光诱导击穿光谱法在空气中定量测定土壤中氮元素方法的研究-基于CN分子谱线

A Research on Quantitative Determination of Nitrogen in the Soil by Laser Induced Breakdown Spectroscopy in the Air-based on CN Molecular Spectral Line

土壤中氮元素的快速检测在现代农业中有重要意义,传统方法前处理复杂不适合现场快速检测。激光诱导击穿光谱法已被证明可以用来对土壤中的元素进行检测,但对于土壤中的氮元素检测,如何规避大气环境中氮气的影响是不可回避的问题。提出了一种基于激光诱导击穿光谱法的空气中土壤全氮检测方法,通过对不同土壤标准样品的CN(388.3nm)分子特征谱线对比分析并建立了分析模型,结果显示,可以很好地规避大气中氮元素的影响,其检出限小于0.14%。对比于N(746.8nm)处的原子特征峰在空气中和氩气中的分析结果,其优势非常明显。

Rapid measurement of soil nitrogen is important in the modern agriculture, and the traditional method is not suitable for fast field-site analysis. The laser-induced breakdown spectroscopy （LIBS） has been shown to be used for the detection of elements in the soil, but for soil nitrogen testing, how to eliminate the impact of the nitrogen in the air is an important process. This paperproposed a method for detecting total nitrogen in air based on laser-induced breakdown spectroscopy by analyzing the molecular characteristic line CN（388.3 nm） of different soil samples and establishing an analytical model, The results show that this method can be very good to avoid the influence of atmospheric nitrogen, and the detection limit is less than 0.14%. Comparing to the results used N atomic emission line at 746.8 nm in the air and argon gas, the advantages of the proposed method are obvious.