An 14N nuclear quadrupole resonance (NQR) spectroscopy method has been developed using the singular spectrum analysis (SSA) based on the principal components concept. For the first time, it was demonstrated that this method can be used as a low cost and non-destructive quantitative method for analyses of small amounts (< 100 mg) of nitrogen containing solids. NQR technique is closely related to nuclear magnetic resonance, but without need for external magnetic field, applicable to solid compounds with quadrupolar nuclei. The hardware configuration using a broadband matching transformer was constructed and advanced algorithms for quantitative analyses of 14N NQR spectra were outlined. The calibration curves obtained, after optimization, for the model compounds, sodium nitrite and urotropin (hexamethylenetetramine), showed excellent linearity up to 500 mg for sodium nitrite at a frequency of 4642 kHz and up to 300 mg for urotropin at a frequency of 3307 kHz. The limits of detection were determined as 41 mg and 24 mg, respectively. The experimental and analytical procedure was simple enough to allow relatively easy practical implementation.

中文翻译：

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使用奇异谱分析 (SSA) 对亚硝酸钠和促尿激素进行 14N NQR 定量以进行数据过滤

使用基于主成分概念的奇异光谱分析 (SSA) 开发了 14N 核四极共振 (NQR) 光谱方法。首次证明该方法可用作分析少量 (< 100 mg) 含氮固体的低成本和非破坏性定量方法。NQR技术与核磁共振密切相关，但不需要外部磁场，适用于具有四极核的固体化合物。构建了使用宽带匹配变压器的硬件配置，并概述了用于 14N NQR 光谱定量分析的高级算法。模型化合物亚硝酸钠和乌洛托品（六亚甲基四胺）优化后得到的校准曲线，亚硝酸钠在 4642 kHz 的频率下高达 500 mg，在频率为 3307 kHz 时显示出高达 300 mg 的乌洛托品线性。检测限分别确定为 41 mg 和 24 mg。实验和分析程序足够简单，可以相对容易地实际实施。