基于阳离子表面活性剂缔合微粒共振瑞利散射光谱法测定痕量O_3  

Resonance Rayleigh Scattering Determination of Trace Ozone Based on the Cationic Surfactant Association Particles

作　　者：刘高伞 梁爱惠[1] 温桂清[1] 蒋治良[1] 

机构地区：[1]珍稀濒危动植物生态与环境保护省部共建教育部重点实验室,广西师范大学环境与资源学院,广西桂林541004

出　　处：《光谱学与光谱分析》2014年第3期725-728,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21267004;21165005;21367005;21307017);广西自然科学基金项目(2013GXNSFFA019003)资助

摘　　要：以pH 4.0 HAC-NaAC缓冲溶液为介质，用硼酸碘化钾溶液（BKI）作为O3吸收剂。O3将I-氧化生成为I2，溶液中过量的I-与I2又可形成I3-，有阳离子表面活性剂（CS）如氯代十六烷基吡啶（CPCl），溴代十四烷基吡啶（TPB），十六烷基三甲基溴化铵（CTMAB），十四烷基苄基二甲基氯化铵（TDMAC）存在时，CS与I3-形成稳定的（CS-I3）n缔合微粒，在470 nm处有一个较强的共振瑞利散射峰（RRS ），随着O3浓度的增大，体系中的I3-增多，I3-与CS形成的（CS-I3）n缔合微粒越多，470 nm处的RRS强度 I增强，O3浓度与其增强值ΔI成线性关系，各体系的线性范围分别为15～50，50～100，5～25，1～50μmol · L -1，回归方程分别为ΔI＝8.81 c-4.01，ΔI＝5.44 c-3.11，ΔI＝15.39 c-1.55，ΔI＝16.88 c＋0.51，检出限分别为4.9，12，2.85，0.56μmol · L -1 O3。实验考察了共存物质的影响，当O3浓度为2.5×10-6 mol · L -1，相对误差在＆#177;10％内时，4.0×10-5 mol · L -1 Hg2＋，8.7×10-5 mol · L -1 Fe3＋，5.0×10-5 mol · L -1 Ca2＋，2.5×10-5 mol · L -1 Zn2＋和Cu2＋，2.8×10-6 mol · L -1 Pb2＋和Cr3＋，4.2×10-5 mol · L -1 Mg2＋，Mn2＋和Ba2＋对体系的测定无干扰。说明该方法具有良好的选择性。选用TDM AC体系检测空气中的O3，结果令人满意。采用激光散射技术研究了（TDM AC-I3）n缔合微粒体系的粒径分布。当通入O3后，过量KI与O3反应形成I3-， I3-与TDMAC反应生成（TDMAC-I3）n缔合微粒，其粒径集中分布在1106～3091 nm之间。In the presence of pH 4.0 HAC-NaAC buffer solution ,using H3 BO3-KI （BKI） as absorption solution ,O3 oxidized KI to produce I2 ,and it reacted with excess I - to form I3- that combined with the cationic surfactant （CS） such as cetylpyridinium chloride （CPCl） ,tetradecyl pyridinium bromide （TPB） ,cetyl trimethyl ammonium bromide （CTMAB） ,and tetradecyl dimeth-ylbenzyl ammonium chloride （TDMAC） to produce stable （CS-I3 ）n association particles ,which exhibited a strong resonance Rayleigh scattering （RRS） peak at 470 nm. Under the chosen conditions ,as the concentration of O3 （C） increased ,the concen-tration of I3- increased ,and the RRS intensity at 470 nm （I470 nm ） increased due to more association particles forming. The in-creased RRS intensity I470 nm was linear with O3 concentration. For the four CS systems ,the linear range was 15~50 ,50~100 ,5~25 and 1~50 μmol · L -1 O3 respectively. The regression equation is ΔI= 8.81c-4.01 ,ΔI= 5.44c-3.11 ,ΔI=15.39c-1.55 ,and ΔI=16.88c＋0.51. The detection limit is 4.9 ,12 ,2.85 and 0.56 μmol · L -1 O3 respectively. The influ-ence of some foreign substances was examined on the determination of 2.5 × 10-6 mol · L -1 O3 ,within ＆#177; 10% relative error.Results showed that a 4.0 × 10-5 mol · L -1 Hg2＋ ,8.7 × 10-5 mol · L -1 Fe3＋ ,5.0 × 10-5 mol · L -1 Ca2＋ ,2.5 × 10-5 mol · L -1 Zn2＋ and Cu2＋ ,2.8 × 10-6 mol · L -1 Pb2＋ and Cr3＋ ,4.2 × 10-5 mol · L -1 Mg2＋ ,Mn2＋ and Ba2＋ do not interfere with the RRS determination. This showed that this RRS method is of good selectivity. The TDMAC system is most sensitive ,and was chosen to detect O3 in air samples. The analytical results were in agreement with that of spectrophotometry results .Further-more ,laser scattering technique was utilized to examine the particle size distribution of （TDMAC-I3 ）n system. Results indicated that the particle size located in the range of 190~531 nm ,in the absence of O3. Upon addition of O3 ,the excess KI reacted

关 键 词：O3 缔合微粒 共振瑞利散射光谱 

分 类 号：O657.3[理学—分析化学]