DOI:10.14135/j.cnki.1006-3080.20170614001金属络合效应对草酸HPLC分析的影响及消除吴雨涵，孙贤波，徐宏勇（华东理工大学资源与环境工程学院，国家环境保护化工过程环境风险评价与控制重点实验室，上海200237）摘要：电镀废水中“金属-络合剂”带来的络合效应可能会降低高效液相色谱（HPLC）对络合剂分析的准确度。本文以镍-草酸作为模式化合物，考察了络合效应对于络合剂草酸HPLC分析的影响，发现200mg/L的镍离子对草酸定性分析的影响较小，保留时间的变化幅度为1.0%；200mg/L的镍离子对草酸定量分析的影响较大，峰面积的分析误差为33.7%。采用氢氧化物沉淀法来消除络合效应，使得峰面积的变化幅度降为1.7%，提高了电镀废水中草酸HPLC分析的准确度。关键词：络合效应；草酸；HPLC；破络中图分类号：X832.1文献标志码：AInfluenceandEliminationofComplexationEffectonHPLCAnalysisofOxalicAcidWUYu-han,SUNXian-bo,XUHong-yong(StateEnvironmentalProtectionKeyLaboratoryofEnvironmentalRiskAssessmentandControlonChemicalProcess,EastChinaUniversityofScienceandTechnology,Shanghai200237,China)Abstract:Thearticleismainlyaboutthecomplexationeffectandtheusefulmethodtoeliminatethiseffect.Thediscussionoftheexperimentresultisaboutthehighperformanceliquidchromatography(HPLC)analysisofnickel-oxalicacidandhydroxideprecipitationpretreatment.Itisknownthatthecomplexationeffectiscausedbymetalionsandcomplexingagentsanditwillpromotetheformationofmetal-complexingagentsunderthedifferentconditions.Thecomplexationeffectbroughtbymetal-complexingagentsmayreducetheanalyticalaccuracyofcomplexingagentsbyHPLC.Sincetherearevariouskindsofmetal-complexingagentsintheelectroplatingwastewater,nickel-oxalicacidischosentobethetypicalmetal-complexingagentinthispaper.TheresearchontheanalysisofoxalicacidbyHPLCthatcanbeinfluencedbythecomplexationeffecthasbeenstudiedfurther.TheUV-visiblewavelengthscanningisassistedtoverifythatthecomplexationeffecthasmadeabigimpactontheHPLCanalysisofoxalicacid.TheHPLCanalysisofoxalicacidisdividedintothequalitativeanalysisandthequantitativeanalysis.Thequalitativeanalysisisfromthedataoftheretentiontime,andthequantitativeanalysisismainlyfromthedataofthepeakarea.Whenaddingthenickelions,theretentiontimeofoxalicacidvariesabout1.2%,soitcanbeconcludedthatthe200mg/LnickelionshaslessimpactonthequalitativeanalysisofoxalicacidbyHPLC.Atthesametime,thevariationofthepeakareaisabout33.7%,soitisfoundthattheinfluenceof200mg/LnickelionsonthequantitativeanalysisofoxalicacidbyHPLCissolarge.Atlast,thepretreatmentmethodofhydroxideprecipitationisproposedtoeliminatethecomplexationeffect.Theprecipitationpretreatmentmakesthevariationofthepeakareareduceto1.7%,whichincreasestheanalyticalaccuracyofoxalicacidbyHPLCintheelectroplatingwastewater.Keywords:complexationeffect；oxalicacid;HPLC；decomplexation收稿日期：2017-06-27作者简介：吴雨涵（1993-），女，江苏人，硕士生，研究方向为电镀络合物。通信联系人：孙贤波，E-mail：xbsun@ecust.edu.cn电镀废水中常用的络合剂包括草酸、乙二胺四乙酸二钠、硫氰酸和乙二胺等，准确测定这些物质的含量对于确定电镀废水的处理方法具有重要的意义。络合剂常用的分析方法有分光光度法[1,2]、高效液相色谱法（HPLC）[3-5]和离子色谱法[6-9]等。其中色谱方法以其较强的分离能力，对实际废水的定性定量分析具有一定的优势。但色谱分析中的金属络合效应可能造成峰形严重拖尾，甚至形成新的杂峰，改变色谱峰形、峰面积，干扰其重现性，进而降低色谱图的定性定量分析的准确度和可信度[10]。已有报道从基本现象上阐述了HPLC中的金属络合效应[10]，但鲜见金属种类及数量与色谱峰峰形间的量效关系的研究，如何消...