| 摘要: |
| 为了提高土壤阳离子交换量测定的准确度，针对《土壤 阳离子交换量的测定 三氯化六氨合钴浸提-分光光度法》（HJ 889—2017）标准的不足，对有机质、pH值、浸提时间、离心时间、浸提液过滤等条件进行优化。结果表明，酸性土壤在测试前调节pH值为 6.0～8.0，振荡1 h，离心10 min ,能够很好地解决测试结果偏低的问题。当有机质质量分数较高，且在380 nm处吸光度很高时，才需要在475 nm处进行吸光度校正。当实际样品基质复杂时，可采用针头过滤的方法，使得测试结果更准确。优化后的方法适用于各种类型土壤的大批量测定。 |
| 关键词: 分光光度法 有机质 离心 酸性土壤 阳离子交换量 三氯化六氨合钴 |
| DOI： |
| 分类号:X833；O657.3 |
| 基金项目: |
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| Method Optimization of Spectrophotometric Determination of Cation Exchange Capacity in Soil |
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WANG Li-min,WU Hui,SHEN Li,SHANG Yu-feng,WANG Bing-hang1,2,3,4
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1.Weihai Ecological Environment Monitoring Center of Shandong Province, Weihai, Shangdong 264200,China;2.Weihai Ecological Environmental Affairs Service Center,Weihai, Shangdong 264200, China;3.College of Chemistry & Chemical and Environmental Engineering, Weifang University, Weifang, Shangdong 261000,China;4.Weihai Ecological Environment Monitoring Center,Weihai Shangdong 264200,China
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| Abstract: |
| To improve the detection accuracy of soil cation exchange capacity, and in view of the shortcomings in the standard of “Soil quality Determination of cation exchange capacity(CEC) Hexamminecobalt trichloride solution/Spectrophotometric method”（HJ 889—2017）, some parameters have been optimized by studying the influence of organic matter, pH value, extraction time, centrifugation time, filtration, etc.The results show that the pH value of acid soil needs to be adjusted to 6.0~8.0 before testing, followed by shaking for 1 hour and centrifuging for 10 minutes, which can solve the problem of negative deviation.Only when both the organic matter content and the absorbance at 380 nm are high, the absorbance at 475 nm needs to be corrected. When the actual sample matrix is complicated, the syringe filter method can be used to make the test result more accurate.The optimized method is suitable for various types of soils and is suitable for monitoring large quantities of soil samples. |
| Key words: Spectrophotometric method Organic matter Centrifugation Acidic soil Cationic exchange capacity（CEC） ［Co(NH3)6］Cl3 |
