Institute of Agricultural Engineering , University of Bonn , Nussallee 5 , D-53115 Bonn , Germany.
Department of Chemistry, Energetic Materials Research , Ludwig-Maximilians University of Munich , Butenandtstr. 5-13 (Haus D) , D-81377 Munich , Germany.
Anal Chem. 2018 Jul 17;90(14):8404-8411. doi: 10.1021/acs.analchem.8b00900. Epub 2018 Jun 28.
Hyperfast GC/MS below 60 s of measurement time has been used for the measurement of explosives. The new flow-field thermal gradient GC (FF-TG-GC) utilizes a modified transport process of the explosives at lowered temperatures. In combination with the focusing effect of the gradient, high-resolution chromatograms are obtained even in very short time intervals. The reduction of the elution temperature by applying a thermal gradient along the chromatographic column is demonstrated by the simulation of the migration of analytes through the column. The simulation shows an interesting effect of the difference between maximum temperature and elution temperature of analytes during their separation with the spatial gradient. The results show the benefit of the gradient elution both from a modeling perspective and by measurements of explosives with low limits of detection (LOD) in the range from 0.1 to 20 μg/mL (0.5 to 150 pg of analyte mass on column). Results were compared to state-of-the-art vacuum outlet GC/MS as a reference method. A correlation between the reduction of elution temperatures and lower LODs are found for thermal labile nitrate ester explosives (EGDN, NG, ETN, and PETN), while no significant influence of the reduced elution temperature on LODs of more stable explosives, like DNT and TNT, was found.
超快速 GC/MS 可在 60 秒内完成测量，已用于爆炸物的测量。新型流场热梯度 GC（FF-TG-GC）利用了在降低温度下爆炸物的改良传输过程。结合梯度的聚焦效果，即使在非常短的时间间隔内也能获得高分辨率的色谱图。通过模拟分析物在柱中的迁移，证明了通过沿色谱柱施加热梯度降低洗脱温度。模拟表明，在分离过程中，分析物的最大温度和洗脱温度之间的差异对空间梯度具有有趣的影响。结果从建模的角度以及通过对检测限（LOD）低至 0.1 至 20μg/mL（柱上分析物质量为 0.5 至 150pg）的爆炸物的测量，展示了梯度洗脱的优势。结果与作为参考方法的最先进的真空出口 GC/MS 进行了比较。对于热不稳定的硝酸酯炸药（EGDN、NG、ETN 和 PETN），发现洗脱温度降低与更低的 LOD 之间存在相关性，而对于更稳定的炸药（如 DNT 和 TNT），降低洗脱温度对 LOD 没有明显影响。
