Quantifying Effects of OM–Cation Interactions on Mid-Infrared FTIR Absorption Spectra of Polygalacturonic Acid

IF 3.3 3区农林科学 Q1 AGRONOMY

Journal of Plant Nutrition and Soil Science Pub Date : 2026-10-01 Epub Date: 2026-06-29 DOI:10.1002/jpln.70093

Ruth H. Ellerbrock, Nisha Bhattarai, Horst H. Gerke

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引用次数: 0

Abstract

Background

The composition of organic matter (OM) was characterized by Fourier transform infrared spectroscopy (FTIR) in terms of the relative number of functional groups. The presence of polyvalent cations in soil and effects of OM–cation interactions on FTIR absorption bands limit the interpretation of FTIR spectra of soil OM.

Aim

Quantify changes in intensity and wave number (WN) ranges for carboxyl groups in FTIR of OM–cation mixtures and identify their relations with cation concentration based on Lambert–Beer's law.

Methods

Freeze-dried mixtures of polygalacturonic acid (PGA) as model substance and CaCl₂ (Ca–PGA) were analyzed with FTIR spectroscopy in mid-infrared WN range using KBr technique. Lambert–Beer's extinction coefficient was determined for WNs in the range of the asymmetric COO⁻ band (ν_aCOO⁻).

Results

The intensity of the ν_aCOO⁻ band maximum in FTIR spectra of Ca–PGA mixtures increased linearly with Ca content, and the band maximum shifted towards smaller WN. Regressions as well as relations of Lambert–Beer's extinction coefficient ratios could be useful to estimate the ν_aCOO⁻ band intensity in FTIR of pure PGA from that of Ca–PGA mixtures.

Discussion

The regression-based approach required a calibration with spectra of “pure” OM. The Lambert–Beer extinction coefficient ratios could be applied without prior calibration if spectra of the same OM–cation mixtures with different cation concentrations were available.

Conclusions

The empirical and extinction coefficient ratio-based methods were both found useful for studying effects of OM–cation interactions on mid-infrared FTIR absorption spectra to characterize OM composition.

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om -阳离子相互作用对聚半乳糖醛酸中红外吸收光谱的定量影响

利用傅里叶变换红外光谱（FTIR）根据官能团的相对数量对有机物（OM）的组成进行了表征。土壤中多价阳离子的存在以及OM -阳离子相互作用对FTIR吸收带的影响限制了土壤OM的FTIR光谱解释。目的根据兰伯特-比尔定律，量化om -阳离子混合物中羧基的红外光谱强度和波数范围的变化，并确定其与阳离子浓度的关系。方法采用KBr技术对冻干后的聚半乳糖醛酸（PGA）与CaCl2 （Ca-PGA）的混合物进行中红外光谱分析。在不对称COO−波段（νaCOO−）范围内确定了WNs的Lambert-Beer消光系数。结果Ca - pga混合物的FTIR光谱中νaCOO−波段最大值的强度随Ca含量的增加而线性增加，且能带最大值向较小的WN偏移。回归和Lambert-Beer消光系数比值关系可用于从Ca-PGA混合物的FTIR中估计纯PGA的ν aco−波段强度。基于回归的方法需要用“纯”OM的光谱进行校准。如果具有不同阳离子浓度的相同om -阳离子混合物的光谱，则可以在没有事先校准的情况下应用Lambert-Beer消光系数比。结论基于经验和消光系数的方法均可用于研究OM -阳离子相互作用对OM中红外吸收光谱的影响，从而表征OM的组成。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Plant Nutrition and Soil Science 农林科学-农艺学

CiteScore

4.70

自引率

8.00%

发文量

审稿时长

8-16 weeks

期刊介绍： Established in 1922, the Journal of Plant Nutrition and Soil Science (JPNSS) is an international peer-reviewed journal devoted to cover the entire spectrum of plant nutrition and soil science from different scale units, e.g. agroecosystem to natural systems. With its wide scope and focus on soil-plant interactions, JPNSS is one of the leading journals on this topic. Articles in JPNSS include reviews, high-standard original papers, and short communications and represent challenging research of international significance. The Journal of Plant Nutrition and Soil Science is one of the world’s oldest journals. You can trust in a peer-reviewed journal that has been established in the plant and soil science community for almost 100 years. Journal of Plant Nutrition and Soil Science (ISSN 1436-8730) is published in six volumes per year, by the German Societies of Plant Nutrition (DGP) and Soil Science (DBG). Furthermore, the Journal of Plant Nutrition and Soil Science (JPNSS) is a Cooperating Journal of the International Union of Soil Science (IUSS). The journal is produced by Wiley-VCH. Topical Divisions of the Journal of Plant Nutrition and Soil Science that are receiving increasing attention are: JPNSS – Topical Divisions Special timely focus in interdisciplinarity: - sustainability & critical zone science. Soil-Plant Interactions: - rhizosphere science & soil ecology - pollutant cycling & plant-soil protection - land use & climate change. Soil Science: - soil chemistry & soil physics - soil biology & biogeochemistry - soil genesis & mineralogy. Plant Nutrition: - plant nutritional physiology - nutrient dynamics & soil fertility - ecophysiological aspects of plant nutrition.