Laboratory of General and Agricultural Microbiology, Dep. of Crop Science, Agricultural Univ. of Athens, 118 55, Athens, Greece.
Dep. of Plant and Environmental Sciences, Faculty of Science, Univ. of Copenhagen, 1871, Frederiksberg C, Denmark.
J Environ Qual. 2020 Sep;49(5):1310-1321. doi: 10.1002/jeq2.20106. Epub 2020 Jul 8.
In recent years, there has been a surge in the number of applications of Fourier-transform mid-infrared (FTIR) spectroscopy for the characterization of environmental samples and prediction of some of their properties whose measurement has traditionally involved time-consuming and costly methods. However, there are several different mid-infrared techniques available, and there is a gap in knowledge regarding the best-suited technique for recording informative spectra of different types of environmental samples. This study compared the three most widespread FTIR techniques using solid and liquid samples. A total of 11 environmental samples belonging to four categories were analyzed with attenuated total reflectance (ATR), photoacoustic (PAS), and diffuse reflectance (DR) FTIR spectroscopy. Overall, PAS-FTIR was the best technique, providing a greater amount of information, especially for opaque samples (i.e., organic waste, biochar, and soil), than ATR-FTIR and DR-FTIR spectroscopy. Attenuated total reflectance FTIR provided the best spectra for soft samples, such as plant materials, probably due to their ability to achieve good optical contact with the ATR crystal. Finally, DR-FTIR performed relatively well for most samples but was found to be more sensitive to moisture in the samples, resulting in noise in specific areas, and was less sensitive in bond vibrations related to Si.
近年来，傅里叶变换中红外（FTIR）光谱技术在环境样品的特性表征和某些性质预测方面的应用越来越多，这些性质的测量传统上需要耗时且昂贵的方法。然而，有几种不同的中红外技术可用，并且对于记录不同类型环境样品的信息丰富的光谱的最佳技术，知识存在差距。本研究使用固体和液体样品比较了三种最广泛使用的 FTIR 技术。使用衰减全反射（ATR）、光声（PAS）和漫反射（DR）FTIR 光谱法分析了总共 11 种属于四个类别的环境样品。总体而言，PAS-FTIR 是最佳技术，比 ATR-FTIR 和 DR-FTIR 光谱法提供了更多的信息，特别是对于不透明样品（即有机废物、生物炭和土壤）。ATR-FTIR 为植物材料等软样品提供了最佳光谱，这可能是由于它们能够与 ATR 晶体实现良好的光学接触。最后，DR-FTIR 对大多数样品表现相对较好，但对样品中的水分更敏感，导致特定区域出现噪声，并且对与 Si 相关的键振动不太敏感。
