摘要
在pH 3.2~5.7的HAc-Na Ac缓冲溶液中,Ag+与Cl-反应形成Ag Cl.当Ag+适当过量时,Ag Cl与Ag+结合形成[Ag Cl·Ag]+阳离子,它能进一步借静电引力和疏水作用力与曙红B(二溴二硝基荧光素)、曙红Y(四溴荧光素)、乙基曙红(四溴荧光素乙酯)、荧光桃红(四氯四溴荧光素)和虎红(四氯四碘荧光素)等多取代荧光素阴离子(HL-)反应生成离子缔合物[(Ag Cl·Ag)HL].该疏水性离子缔合物可在水相的挤压作用和范德华力的作用下,进一步聚集形成平均粒径约为20 nm的纳米微粒.此时仅引起吸收光谱和荧光光谱的微小变化,但能导致共振瑞利散射(RRS)以及倍频散射(FDS)和二级散射(SOS)等共振非线性散射(RNLS)的显著增强,其中以曙红B体系最灵敏.曙红B体系的最大RRS、FDS和SOS波长分别位于315 nm、350 nm和560 nm处,3种散射增强(ΔIRRS、ΔIFDS和ΔISOS)在一定范围内均与氯离子浓度成正比,均可用于氯离子的测定.其中以FDS法最灵敏,RRS法次之.3种方法(RRS、FDS和SOS法)对于氯离子的检测,曙红B体系的线性范围分别是0.005~1.22μg/m L、0.004~2.92μg/m L和0.01~1.94μg/m L,检出限分别为1.50 ng/m L、1.20 ng/m L和3.90 ng/m L.本文研究了[(Ag Cl·Ag)HL]n纳米微粒的形成、散射强度的提高、适宜的反应条件及影响因素,考察了共存物质的影响,表明方法具有良好的选择性.据此利用上述反应,发展一种RRS、SOS和FDS技术高灵敏、高选择性和简便、快速测定环境空气和废气中HCl及环境水样中氯化物的新方法.文中还对反应机理和散射增强的原因进行了讨论.
In pH 3.2-5.7 acetate （HAc-NaAc） buffer solution, AgC1 forms by the reaction of Ag＋ with CI can bind with excessive Ag＋ to form a [AgC1·Ag]＋ cation. The cation further reacts with Polysubstituted fluorescein dyes （eosin B, eosin Y, tiger red, phloxine and ethyl eosin） anion （HL-） to form ion-association complexes [（AgC1·Ag）HL] by virtue of electrostatic attraction and hydrophobic force. Then the complexes draw close to each other and further aggregate to produce [（AgC1·Ag）HL]n nanoparticles with an average diameter of 20 nm due to the extrusion action of water and Van der Waals force. As a result, the spectra of absorption and fluorescence are changed a little, but resonance Rayleigh scattering （RRS） and resonance non-linear scattering （RNLS） such as frequency doubling scattering （FDS） and second-order scattering （SOS） are enhanced greatly. The sensitivity of Ag＋-C1--eosin B system is the highest among six systems. Its maximum wavelengths of RRS, FDS and SOS are located at 315,350 and 560 nm, respectively. The increments of three scattering intensity （AIRRs, Alvos and A/sos） are directly proportional to the concentration of C1- in certain ranges, and three scattering methods can be applied to the determination of C1-. Among them, the FDS method has the highest sensitivity, and followed by the RRS method. Take the eosin B system with the highest sensitivity as an example, the linear ranges and the detection limits for C1- of the three methods （RRS, FDS and SOS） are 0.005-1.22 μg/mL, 0.004-2.92 μg/mL, 0.01-1.94 μg/mL and 1.50 ng/mL, 1.20 ng/mL, 3.90 ng/mL, respectively. In this paper, the formation of [（AgC1·Ag）HL]n nanoparticles, the enhancement of scattering intensity, the optimum conditions and the influencing factors have been investigated. Meanwhile, the effects of coexisting substances have been discussed and the results show that the method has good selectivity. Based on the above researches, a highly sensitive, selective, simple and fast method for the determination of HC1 in environmental air and waste gas samples and chloride in environmental water samples by RRS, SOS and FDS techniques has been developed. In addition, the reaction mechanism is discussed.
出处
《中国科学：化学》
CAS
CSCD
北大核心
2015年第2期217-226,共10页
SCIENTIA SINICA Chimica
基金
国家自然科学基金(20475045)
国家水体污染控制与治理科技重大专项(2009ZX07104-001
2012ZX07104-001)
重庆市科技攻关项目(CSTC
2011gg B20001)资助
关键词
多取代荧光素
共振瑞利散射
共振非线性散射
氯化氢
氯化物
polysubstituted fluorescein dyes, resonance Rayleigh scattering, resonance non-linear scatteringhydrogenchloride, chlorid
