Background: The organic matter (OM) in soils interacts with polyvalent cations such as Ca²⁺ through hydroxyl (OH), carboxylic acid, ester, keto, aldehyde (summarized as C=O), and carboxylate (COO⁻) functional groups. Such interactions affect the bonding strength of the double bond between the C and the O atom in the functional groups, which is assumed to shift the wavenumber (WN) region of O–H (hydroxyl), C=O, COO⁻, and OM_cat (i.e., C=O interacting with cations plus O–H groups) absorption band maxima in the Fourier transform infrared (FTIR) spectra. Such band shifts limit the evaluation of spectral information on OM in soil samples.

中文翻译：

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由 OM-阳离子相互作用解释的 FTIR 光谱带位移

背景：土壤中的有机质 (OM)通过羟基 (OH)、羧酸、酯、酮、醛（概括为 C=O）和羧酸盐 (COO ^- ) 官能团与 Ca ²⁺等多价阳离子相互作用。这种相互作用会影响官能团中 C 和 O 原子之间双键的键合强度，假设它移动了 O-H（羟基）、C=O、COO ^-和 OM的波数 (WN) 区域_cat（即，C=O 与阳离子和O-H 基团相互作用）傅里叶变换红外 (FTIR) 光谱中的吸收带最大值。这种带移限制了对土壤样品中 OM 光谱信息的评估。