ABSTRACT To track changes in organic matter (OM) in peat soils, analytical techniques are needed that effectively characterize their chemical components. Pyrolysis-gas chromatography/mass spectrometry is a useful method for obtaining a chemical “fingerprint” of OM. To obtain representative fingerprints, the pyrolysis process should be highly reproducible and representative of the original sample; however, these key indicators for successful volatilization are underreported in the literature. We investigated the influence of instrumental parameters (temperatures, heating rates, sample mass), original organic C and nitrogen (N) content, and instrument type (“slow” vs “flash”), on volatilization of different peat samples by monitoring sample mass loss and changes in organic C and N content before and after pyrolysis. Average percent C by mass volatilized (“C pyrolysis efficiency”) across all pyrolysis experiments conducted (mass, instrument types, and settings) was 47.8 ± 1.8%. Sample mass was not a major driver; however, instrument temperatures, heating rate, and original N content had a significant influence on pyrolysis efficiency. N pyrolysis efficiency occurred at significantly higher rates (56.7–75.8%) than C pyrolysis efficiency (45.1–51.6%). N pyrolysis efficiency was also negatively influenced by decreasing concentrations of original sample N, suggesting that N-containing compounds may undergo preferential volatilization in high pyrolysis temperatures. Our data suggest that C pyrolysis efficiency is relatively insensitive to instrumental parameters; whereas when seeking to identify N-containing compounds, appropriate temperatures and heating rates must be chosen. These results provide an expected range for pyrolysis efficiency as a reference for peat samples analyzed with this technique.

中文翻译：

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研究仪器参数和化学成分对泥炭热解效率的影响

摘要 为了跟踪泥炭土壤中有机质 (OM) 的变化，需要有效表征其化学成分的分析技术。热解-气相色谱/质谱是获得 OM 化学“指纹”的有用方法。为获得有代表性的指纹，热解过程应具有高度可重复性并能代表原始样品；然而，这些成功挥发的关键​​指标在文献中被低估了。我们通过监测样品质量研究了仪器参数（温度、加热速率、样品质量）、原始有机碳和氮 (N) 含量以及仪器类型（“慢速”与“闪光”）对不同泥炭样品挥发的影响热解前后有机碳和氮含量的损失和变化。在进行的所有热解实验（质量、仪器类型和设置）中，C 的平均挥发质量百分比（“C 热解效率”）为 47.8 ± 1.8%。样品质量不是主要驱动因素；然而，仪器温度、加热速率和原始 N 含量对热解效率有显着影响。N 热解效率的发生率 (56.7-75.8%) 显着高于 C 热解效率 (45.1-51.6%)。N 热解效率也受到原始样品 N 浓度降低的负面影响，这表明含 N 化合物可能在高热解温度下优先挥发。我们的数据表明 C 热解效率对仪器参数相对不敏感；而在寻找含氮化合物时，必须选择合适的温度和加热速率。这些结果提供了热解效率的预期范围，作为使用该技术分析的泥炭样品的参考。