Feasibility Study on the Application of Automatic Potentiometric Titrator in the Measurement of Organic Carbon in Marine Sediments
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摘要: 自动电位滴定仪具有操作简便、测定速度快的优势，减少了人为操作的影响，本文使用自动电位滴定仪测定海洋沉积物中有机碳的含量，并与国家标准（GB 17378.5-2007）中根据滴定过程中溶液颜色变化用肉眼判定滴定终点的方法进行了对比分析，确定通过仪器自动判断滴定终点实现准确测定的可行性。结果表明：自动电位滴定的方法检出限为0.029%，人工肉眼判定终点的方法检出限为0.086%，在滴定终点判定方面两种方法无显著性差异，但自动电位滴定仪的准确度和精密度更优，在一定程度上可代替肉眼判定滴定终点。实际应用过程中也发现，当滴定的溶液体系由于氧化还原反应、络合作用等影响因素使电位变化较为复杂时，自动电位滴定仪有可能会得到多个等当点而无法判断哪个等当点是真正的目标等当点，此时需要利用肉眼进行辅助确定。Abstract: The automatic potentiometric titrator has the advantages of being simple to operate and giving fast measurement results, which could reduce artifical influence due to manual operation. In this study, organic carbon content of marine sediments was determined by Automatic Potentiometric Titrator. In order to investigate if the Automatic Potentiometric Titrator could accurately determine the titration end-point, this method was compared with the national standard method (GB 17378.5-2007) in which the titration end-point was visually determined through color change. Results show that the detection limits of the automatic potentiometric titrator and manual methods were 0.029% and 0.086%, respectively. There are no significant differences between the two methods in titration end-point determination. However, the Automatic Potentiometric Titrator has better accuracy and precision than manual operation. Therefore, under certain circumstances, Automatic Potentiometric Titrator can take over the visual method to determine the titration end-point. It is also noteworthy that there are some problems in measuring real samples. For example, the Automatic Potentiometric Titrator might be unable to accurately determine the target titration end-point when there are complex electrical potential changes due to redox reactions and chelating interactions in the reaction system. On this occasion, the titration end-point can be determined visually.
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表 1 两种滴定终点判定方法测定海洋沉积物标准物质中有机碳含量的结果比较
Table 1. Comparison of the organic carbon content in the marine sediments standards obtained by two titration end-point determination methods
方法 GBW07335的 有机碳含量 测定值与参考值 的标准偏差(%) 相对标准 偏差(%) 测定值 (%) 参考值 (%) 方法a(根据颜色变化 判定滴定终点) 0.586 0.6 2.33 3.94 方法b(自动电位滴定仪 判定滴定终点) 0.592 0.6 1.33 1.62 
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[1] 曲建升,孙成权,张志强,等.全球变化科学中的碳循环研究进展与趋向[J].地球科学进展,2003,18(6):980-987. http://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ200306021.htm
Qu J S,Sun C Q,Zhang Z Q,et al.Trends and Advances of the Global Chance Studies on Carbon Cycle[J].Advance in Earth Sciences,2003,18(6):980-987. http://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ200306021.htm
[2] Ni H G,Lu F H,Luo X L,et al.Riverine Inputs of Total Organic Carbon and Suspended Particulate Matter from the Pearl River Delta to the Coastal Ocean off South China[J].Marine Pollution Bulletin,2008,56(6):1150-1157. doi: 10.1016/j.marpolbul.2008.02.030
[3] Ziegler M,Jilbert T,de Lange G J,et al.Bromine Counts from XRF Scanning as an Estimate of the Marine Organic Carbon Content of Sediment Cores[J].Geochemistry,Geophysics,Geosystems,2008,9(5):303-307. http://cn.bing.com/academic/profile?id=1641689766&encoded=0&v=paper_preview&mkt=zh-cn
[4] 周述琼,章骅,但德忠.水中总有机碳测定方法研究进展[J].四川环境,2006,25(2):111-115. http://www.cnki.com.cn/Article/CJFDTOTAL-SCHJ200602028.htm
Zhou S Q,Zhang H,Dan D Z.Progress on Methods for Determination of TOC in Water[J].Sichuan Environment,2006,25(2):111-115. http://www.cnki.com.cn/Article/CJFDTOTAL-SCHJ200602028.htm
[5] Hansell D A,Peltzer E T.Spatial and Temporal Varia-tions of Total Organic Carbon in the Arabian Sea[J].Deep Sea Research PartⅡ:Topical Studies in Oceanography,1998,45(10):2171-2193.
[6] Martinez-Soto M C,Martínez G.Organic Carbon,Phosp-horus and Nitrogen in Surface Sediments of the Marine-Coastal Region North and South of the Paria Peninsula,Venezuela[J].Environmental Earth Sciences,2012,65(2):429-439. doi: 10.1007/s12665-011-1319-y
[7] Stolpovsky K,Dale A W,Wallmann K.Toward a Para-meterization of Global-scale Organic Carbon Mineralization Kinetics in Surface Marine Sediments[J].Global Biogeochemical Cycles,2015,29:812-829. doi: 10.1002/2015GB005087
[8] 于雯泉,钟少军.海洋沉积物有机碳分析方法中干燥预处理过程人为误差的发现及其意义[J].环境科学学报,2007,27(5):861-867. http://www.cnki.com.cn/Article/CJFDTOTAL-HJXX200705024.htm
Yu W Q,Zhong S J.Freeze-drying Pretreatment Improves Organic Carbon Determination of Marine Sediments[J].Acta Scientiae Circumstantiae,2007,27(5):861-867. http://www.cnki.com.cn/Article/CJFDTOTAL-HJXX200705024.htm
[9] 刘昌岭,朱志刚,贺行良,等.重铬酸钾氧化-硫酸亚铁滴定法快速测定海洋沉积物中有机碳[J].岩矿测试,2007,26(3):205-208. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20070372&flag=1
Liu C L,Zhu Z G,He X L,et al.Rapid Determination of Organic Carbon in Marine Sediment Samples by Potassium Dichromate Oxidation-Ferrous Sulphate Titrimetry[J].Rock and Mineral Analysis,2007,26(3):205-208. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20070372&flag=1
[10] 黄颖华,张浩.两种测定海洋沉积物中总有机碳方法的比较[J].广西科学院学报,2013,29(4):227-229. http://www.cnki.com.cn/Article/CJFDTOTAL-GXKX201304005.htm
Huang Y H,Zhang H.Comparison of Two Methods for Determining Total Organic Carbon Content in Marine Sediment[J].Journal of Guangxi Academy of Sciences,2013,29(4):227-229. http://www.cnki.com.cn/Article/CJFDTOTAL-GXKX201304005.htm
[11] Shi X F,Shen S X,Yi H,et al.Modern Sedimentary Environments and Dynamic Depositional Systems in the Southern Yellow Sea[J].Chinese Science Bulletin,2003,48(1):1-7. doi: 10.1007/BF03183324
[12] 孙萱,宋金明,于颖,等.元素分析仪快速测定海洋沉积物TOC和TN 的条件优化[J].海洋科学,2014,38(7):14-19. http://www.cnki.com.cn/Article/CJFDTOTAL-HYKX201407003.htm
Sun X,Song J M,Yu Y,et al.A Rapid Method for Determing the Total Organic Carbon and Total Nitrogen in Marine Sediments with an Elemental Analyzer[J].Marine Sciences,2014,38(7):14-19. http://www.cnki.com.cn/Article/CJFDTOTAL-HYKX201407003.htm
[13] 马德起,谷松海,张国胜,等.自动电位滴定测定锰矿石中锰的方法研究[J].岩矿测试,2013,32(4):595-599. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20130415&flag=1
Ma D Q,Gu S H,Zhang G S,et al.Determination of Total Manganese in Manganese Ores with an Automatic Potentiometric Titration Method[J].Rock and Mineral Analysis,2013,32(4):595-599. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20130415&flag=1
[14] 郝会军,杨俐苹,金继运.自动电位滴定法测定土壤有机质含量[J].中国土壤与肥料,2011(1):83-87. http://www.cnki.com.cn/Article/CJFDTOTAL-TRFL201101020.htm
Hao H J,Yang L P,Jin J Y.Determination of Soil Organic Matter by Automatically Potentiometric Titration Method[J].Soils and Fertilizers Sciences in China,2011(1):83-87. http://www.cnki.com.cn/Article/CJFDTOTAL-TRFL201101020.htm
[15] Cristiano B F G,Delgado J U,da Silva J W S,et al.Semi-automated Potentiometric Titration Method for Uranium Characterization[J].Applied Radiation and Isotopes,2012,70(7):1373-1375. doi: 10.1016/j.apradiso.2011.11.025
[16] Medwick T,Kirschner E.Evaluation of Automatic Poten-tiometric Titrator in Nonaqueous Titrations[J].Journal of Pharmaceutical Sciences,1966,55(11):1296-1300. doi: 10.1002/jps.2600551126
[17] 李小涵,王朝辉.两种测定土壤有机碳方法的比较[J].分析仪器,2009(5):78-80. http://www.cnki.com.cn/Article/CJFDTOTAL-FXYQ200905024.htm
Li X H,Wang Z H.Comparison of Two Soil Organic Carbon Determination Methods[J].Analytical Instru-mentation,2009(5):78-80. http://www.cnki.com.cn/Article/CJFDTOTAL-FXYQ200905024.htm
[18] 徐金龙,刘中勇,华斌,等.分析化学中检出限问题探讨[J].检验检疫学刊,2012,22(6):74-76. http://www.cnki.com.cn/Article/CJFDTOTAL-XDSJ201206023.htm
Xu J L,Liu Z Y,Hua B,et al.Discussion of Detection Limit Concept Question in Analytical Chemistry[J].Journal of Inspection and Quarantine,2012,22(6):74-76. http://www.cnki.com.cn/Article/CJFDTOTAL-XDSJ201206023.htm
[19] 周作明,周琪.Fe(Ⅱ)-EDTA/K2S2O8降解苯酚及反应动力学分析[J].化工进展,2012,31(5):1154-1159. http://www.cnki.com.cn/Article/CJFDTOTAL-HGJZ201205037.htm
Zhou Z M,Zhou Q.Mechanism and Kinetics Analysis of the Phenol Degradation by Fe(Ⅱ)-EDTA/K2S2O8 Process[J].Chemical Industry and Engineering Progress,2012,31(5):1154-1159. http://www.cnki.com.cn/Article/CJFDTOTAL-HGJZ201205037.htm
[20] 高迎新,张昱,杨敏.Fenton反应中氧化还原电势的变化规律[J].环境化学,2004,23(2):135-139. http://www.cnki.com.cn/Article/CJFDTOTAL-HJHX200402002.htm
Gao Y X,Zhang Y,Yang M.Characteristics of ORP in Fenton's Reaction[J].Environmental Chemistry,2004,23(2):135-139. http://www.cnki.com.cn/Article/CJFDTOTAL-HJHX200402002.htm
[21] 赵怀颖,吕庆斌,巩爱华,等.自动电位滴定技术精确测定铜矿石中高含量铜的方法研究[J].岩矿测试,2015,34(6):672-677. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20150611&flag=1
Zhao H Y,Lü Q B,Gong A H,et al.Accurate Measurement of High Copper in Copper Ores with Automatic Potentiometric Titration Technique[J].Rock and Mineral Analysis,2015,34(6):672-677. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20150611&flag=1
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