Evaluation of NaOH leaching techniques to extract humic acids from palaeosols

doi:10.1016/S0168-583X(00)00221-4

IEECAS OpenIR > 黄土与第四纪地质国家重点实验室（1985-2004）

	Evaluation of NaOH leaching techniques to extract humic acids from palaeosols
	Head, MJ; Zhou, WJ
	2000-10
发表期刊	NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
卷号	172 页码:434-439
文章类型	Article; Proceedings Paper
摘要	It can be shown quite conclusively that the often used technique (AAA) of leaching palaeosol samples with hot or boiling dilute HCl solution, followed by treatment with up to 2% NaOH solution and a further treatment with dilute HCl solution may not remove all of the so-called humic acids from palaeosol samples. In fact, in many cases it does not remove any of the humic acids, only carbohydrates, amino acids and other organic compounds. This can be shown by examination of the visible spectrum (400-700 nm) of the "humic acid" extract in alkaline solution. Hence, many of the reported C-14 results from the "humin" fraction of palaeosols are actually from the humic acid fraction which is tightly bound to the clay component of the palaeosol. The NaOH leach also has the potential to introduce carboxylic acid groups from atmospheric CO2 into phenol groups. A reevaluation of humic acid extracts of palaeosols collected from the Loess Plateau in China has been made, with analyses comparing the properties of the various organic extracts. Also, an extraction technique based on recommendations from the International Humic Substances Society, incorporating removal of impurities by chromatography plus a decarboxylation step is proposed. (C) 2000 Elsevier Science B.V. All rights reserved.
关键词	humic acids soil chemistry palaeosols radiocarbon dating decarboxylation visible spectrometry
学科领域	Instruments & Instrumentation ; Nuclear Science & Technology ; Physics
DOI	10.1016/S0168-583X(00)00221-4
关键词[WOS]	C-14
收录类别	SCI ; SCIE
语种	英语
WOS研究方向	Instruments & Instrumentation ; Nuclear Science & Technology ; Physics, Atomic, Molecular & Chemical ; Physics, Nuclear
WOS记录号	WOS:000165231000075
出版者	ELSEVIER SCIENCE BV
引用统计	被引频次：15[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.ieecas.cn/handle/361006/12026
专题	黄土与第四纪地质国家重点实验室（1985-2004）
推荐引用方式 GB/T 7714	Head, MJ,Zhou, WJ. Evaluation of NaOH leaching techniques to extract humic acids from palaeosols[J]. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS,2000,172:434-439.
APA	Head, MJ,&Zhou, WJ.(2000).Evaluation of NaOH leaching techniques to extract humic acids from palaeosols.NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS,172,434-439.
MLA	Head, MJ,et al."Evaluation of NaOH leaching techniques to extract humic acids from palaeosols".NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 172(2000):434-439.