锑膜电极检测天然彩棉和染色棉中痕量重金属
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摘要
以锑膜电极为工作电极,采用微分脉冲阳极溶出伏安法直接测定天然彩色棉和染色棉样品中痕量铅和镉,考察了支持电解质、锑膜浓度、富集电位和富集时间等因素对检测结果的影响。结果表明,在0.01 mol/L HCl溶液中,锑膜质量浓度350μg/L,富集电位-1.2V,富集时间180 s的条件下,锑膜电极对铅和镉的氧化溶出具有良好的电化学响应。当Pb(Ⅱ)和Cd(Ⅱ)离子的质量浓度在5~100μg/L的范围内,其阳极溶出峰电流与Pb(Ⅱ)和Cd(Ⅱ)浓度呈良好的线性关系,Pb(Ⅱ)和Cd(Ⅱ)的检出限分别为0.52μg/L和0.82μg/L。利用锑膜电极连续测定50μg/L Pb(Ⅱ)和Cd(Ⅱ)15次,相对标准偏差分别为4.7%和6.3%,说明该方法具有良好的重现性和稳定性。将该方法应用于天然彩色棉和染色棉中痕量Pb(Ⅱ)和Cd(Ⅱ)的测定,其测定结果与电感耦合等离子体质谱法测定结果基本一致。
In this work,an antimony film electrode(SbFE) is used as a possible alternative for electrochemical stripping analysis of trace Pb(Ⅱ) and Cd(Ⅱ) in naturally colored cotton and dyed cotton samples.The SbFE is prepared in situ on a glassy carbon substrate electrode and employed in combination with anodic stripping voltammetry.Several key operational parameters influencing the electro analytical response of SbFE are examined and optimized,such as supporting electrolyte,antimony ion concentration,deposition potential and deposition time.Under the condition of HCI solution 0.01 mol/L,concentration of antimony film 350 μg/L,deposition potential-1.2 V and deposition time 180 s,the antimony film electrode has good electrochemical response to lead and cadmium oxidation.The electrode reveals good linear behavior in the examined concentration ranging from 5 to 100 μg/L for both Pb(Ⅱ) and Cd(Ⅱ),with a limit of detection(S/N=3) of 0.52 μg/L for Pb(Ⅱ),0.82 μg/L.for Cd(Ⅱ).The reproducibility of the analytical signals is characterized by a relative standard deviation(RSD) of 4.7%for Pb(Ⅱ) and 6.3%for Cd(Ⅱ)(50 μg/L,n=15).The SbFE is successfully applied to determine Pb and Cd in naturally colored cotton and dyed cotton samples,and the results are in agreement with those of inductively coupled plasma-mass spectrometry(ICP-MS).
In this work,an antimony film electrode(SbFE) is used as a possible alternative for electrochemical stripping analysis of trace Pb(Ⅱ) and Cd(Ⅱ) in naturally colored cotton and dyed cotton samples.The SbFE is prepared in situ on a glassy carbon substrate electrode and employed in combination with anodic stripping voltammetry.Several key operational parameters influencing the electro analytical response of SbFE are examined and optimized,such as supporting electrolyte,antimony ion concentration,deposition potential and deposition time.Under the condition of HCI solution 0.01 mol/L,concentration of antimony film 350 μg/L,deposition potential-1.2 V and deposition time 180 s,the antimony film electrode has good electrochemical response to lead and cadmium oxidation.The electrode reveals good linear behavior in the examined concentration ranging from 5 to 100 μg/L for both Pb(Ⅱ) and Cd(Ⅱ),with a limit of detection(S/N=3) of 0.52 μg/L for Pb(Ⅱ),0.82 μg/L.for Cd(Ⅱ).The reproducibility of the analytical signals is characterized by a relative standard deviation(RSD) of 4.7%for Pb(Ⅱ) and 6.3%for Cd(Ⅱ)(50 μg/L,n=15).The SbFE is successfully applied to determine Pb and Cd in naturally colored cotton and dyed cotton samples,and the results are in agreement with those of inductively coupled plasma-mass spectrometry(ICP-MS).
引文
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[2]陈飞,徐殿斗,唐晓萍,等.ICP-OES内标法同时测定纺织品中砷、锑、铅等9种可提取元素[J].分析试验室,2011,30(4):89-92.
[3]郭维,于涛,闫婧,等.全谱直读ICP-MS法测定纺织品中重金属总量[J].理化检验-化学分册,2006,42(7):547-549.
[4]傅科杰,杨力生,童鲁波,等.纺织品中残留重金属的来源因素分析[J].检验检疫科学,2004,144(4):25-27.
[5]吴春华,赵洋,马琳,等.微波等离子体原子发射光谱(MP-AES)法同时测定皮革及纺织品中重金属元素[J].环境化学,2012,31(1):126-129.
[6]王彦芬,张绪宏,傅惠敏,等.纯棉纺织品中八种痕量重金属元素ICP-AES分析方法研究[J].南开大学学报,2007,40(5):7-10.
[7]WANG J.Stripping Analysis:Principles,Instrumentation and Applications[M].Deerfield Beach,FL:VCH,1985.
[8]MA F,JAGNER D,RENMAN L.Mechanism for the electrochemical stripping reduction of the nickel and cobalt dimethylglyoxime complexes[J].Anal.Chem.,1997,69(9):1782-1784.
[9]BRETT C M A,FUNGARO D A.Poly(ester sulphonic acid)coated mercury thin film electrodes:characterization and application in batch injection analysis stripping voltammetiy o f heavy metal ions[J].Talanta,2000,50(6):1223-1231.
[10]BAREK J,FOGG A G,MUCK A.Polarography and voltammetiy at mercury electrodes[J].J.Anal.Chem.,2001,31(4):291-309.
[11]XU H,ZENG L P,XING S J,et al.Nafion-coated bismuth film electrodes for the determination o f trace lead and cadmium in herbal medicines by anodic stripping voltammetry[J].Chin.J.Chem.,2008,26(5):847-853.
[12]BARCELO C,SERRANO N,ARINO C,el al.Ex-situ antimony screen-printed carbon electrode for voltammetric determination of Ni(n)-ions in wastewater[J].Electroanal.,2016,28(3):640-644.
[13]Perez-Rafols C,Serrano N,Diaz-Cruz J M,et al.New approaches to antimony film screen-printed electrodes using carbon-based nanomaterials substrates[J].Anal.Chim.Acta,2016,916:17-23.