1. 黑龙江大学中俄学院, 黑龙江 哈尔滨 150080
2. Institute of Earth Sciences, St. Petersburg State University, St. Petersburg 199034, Russia
3. 吉首大学旅游学院, 湖南 吉首 416000
Spectroscopic Characteristics of Soil Humus Components Extracted With Acetone Hydrochloric Acid Mixture
SONG Ge1, 2, KONG Xiang-shi3*
1. Sino-Russia Institute, Heilongjiang University, Harbin 150080, China
2. Institute of Earth Sciences, St. Petersburg State University, St. Petersburg 199034, Russia
3. School of Tourism, Jishou University, Jishou 416000, China
Abstract：The components of soil humic acid (HA) and humin (HU) were extracted by acetone hydrochloric acid mixture, their elemental components were analyzed, and their spectroscopic characteristics were analyzed by UV-Vis diffuse reflectance and infrared spectroscopy. Elemental analysis showed that HA had higher carbon, hydrogen, nitrogen, and sulfur contents while having lower oxygen content than HU. Atomic ratio analysis showed that HA had a higher condensation degree and more complex molecular structure than HU. The UV-Vis diffuse reflectance spectrum analysis showed that HA and HU had no obvious characteristic peak because of the complex composition of humic substances and the mutual interference of various functional groups. The UV absorbance decreased with the increase of wavelength, and HA contained more light absorbing organic components. The UV characteristic parameters of SUV254 and E4/E6 showed that HA had higher aromaticity and humification degree than HU. Infrared spectrum analysis shows that HA and HU have similar infrared spectra. However, the absorption intensity of characteristic absorption peaks of each research object is different. The vibration amplitude of HA in soil layer of 20～40 cm cultivated black soil and 18～37 cm uncultivated gray soil is larger, indicating that they had high contents of phenolic compounds, hydroxyl functional groups, aliphatic compounds, carboxyl groups, aldehydes, ketones, ethers, carbohydrate and amine compounds. The vibration amplitude of HU in soil layer of 10～20 cm cultivated black soil and 18～37 cm uncultivated gray soil is large, indicating that they contain more phenolic compounds, carboxylic acid, aliphatic hydrocarbons and sugars. In addition, intensity comparison of each absorption peak in the infrared spectrum showed that the content of phenolic compounds, hydroxyl functional groups and aliphatic compounds in HA and HU of black soil increased after cultivation. In contrast, the content of phenolic compounds, carboxyl groups and aliphatic compounds in HA and HU of gray soil decreased after cultivation. These results showed that cultivation has relatively little impact on black soil organic matter, and to a certain extent, increased soil organic matter content, but promoted the decomposition of gray soil organic matter. In conclusion, the acetone hydrochloric acid mixture extraction method provides new technical support for studying the biochemical and physiological activities of humic substances, which provide a theoretical basis for rational utilization of soil resources.
[1] Canellas L P, Olivares F L, Aguiar N O, et al. Scientia Horticulturae, 2015, 196: 15.
[2] DOU Sen, LI Yan, GUAN Song, et al(窦 森, 李 艳, 关 松, 等). Acta Pedologica Sinica(土壤学报), 2016, 53(4): 821.
[3] TONG Li-hong, ZHU Ling, ZHAO Nan, et al(仝利红, 祝 凌, 赵 楠, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2021, 41(2): 523.
[4] SHI Ya-fang, LIU Zi-wen, DAI Yun-chao, et al(石亚芳, 刘子雯, 代允超, 等). Chinese Science Bulletin(科学通报), 2021, 66(20): 2596.
[5] Rigobello E S, Campos S X, Azevedo E R, et al. Rev. Ambient. água, 2017, 12(5): 774.
[6] Silva R R, Lucena G N, Machado A F, et al. Comunicata Scientiae, 2018, 9(2): 264.
[7] Hargitai L. Environmental International, 1994，20: 43.
[8] Kim H C, Yu M J, Han I. Appl. Geochem., 2006, 21: 1226.
[9] Kononova A M M. Oxford: Pergamon Press, 1996: 40.
[10] Stevenson F J. Humus Chemistry: Genesis, Composition, Reactions. New York: John Wiley & Sons, 1994.
[11] Saab S C, Martin-Neto L. Quim. Nova, 2007, 30(2): 260.
[12] Rigobello E S, Campos S X, Azevedo E R. Rev. Ambient. água, 2020, 12(5): 774.
[13] Samios S, Lekkas T, Nikolaou A, et al. Desalination, 2007, 210: 125.
[14] Nuzzo A, Sanchez A, Fontaine B, et al. Journal of Geochemical Exploration, 2013: 1.
[15] Zheng Yanyun, Zhang Jiabao, Tan Jun, et al. Acta Pedologicasinica, 2019, 56(2): 386.
[16] Zhu Shu, Dou Sen, Guan Song, et al. Acta Pedological Sinica, 2016, 53(1): 127.
[17] Helal Aly A, Murad G A, Helal A A. Arabian Journal of Chemistry, 2011, 4(1): 51.
