In a NaAc-HAc buffer medium (pH = 5.9 ), famotidine (FMTD) reacted with Hg ( Ⅱ ) to form chelate cation [ Hg (FMTD) ] 2 +, which further reacted with anionic surfactants (AS) such as sodium dodecylsulfate ( SLS), sodium dodecylbenzene sulfonate (SDBS) and sodium dodecylsulphate (SDS) to form ternary mixed ligand complex [ Hg(FMTD) (AS) 2 ]· As a result, the resonance Rayleigh scattering(RRS), secondorder scattering(SOS) and frequency doubling scattering(FDS) were enhanced greatly. Their maximum wavelengths were located at 345-352 nm, 544 nm and 352 nm, respectively. The three scattering intensity(Δl)were proportional to the FMTD concentration in a certain range, and their detection limits were 3.3-3.9ng/mL( RRS method), 14.6-16.3 ng/mL( SOS method) and 7.0-8.5 ng/mL( FDS method). On the basis of this result, the simple, rapid, accurate and sensitive light scattering method had been proposed to determine FMTD in injection, serum and urine sample. The effects of [ Hg(FMTD) (AS)2 ] on the absorption andRRS spectra were investigated, and the reasons of enhancement for RRS were also discussed.%在pH=5.9的NaAc-HAc缓冲溶液中,法莫替丁(FMTD)与Hg(Ⅱ)反应形成五元环螯合阳离子([Hg(FMTD)]2+),再进一步与十二烷基硫酸钠(SLS),十二烷基苯磺酸钠(SDBS)和十二烷基磺酸钠(SDS)等阴离子表面活性剂(AS)反应,形成1∶1∶2的三元混配物[Hg(FMTD)(AS)2].此时,体系的共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)明显增强.最大的散射波长分别位于345～352 nm(RRS法)、544 nm(SOS法) 和352 nm(FDS法),3种散射强度(ΔI)的顺序均为SLS体系>SDS体系>SDBS体系,在一定范围内ΔI与FMTD的浓度呈良好的线性关系,检出限分别为3.3～3.9 ng/mL(RRS法)、14.6～16.3 ng/mL(SOS法)和7.0～8.5 ng/mL(FDS法).据此建立了灵敏度高、选择性好、快速准确测定FMTD的光散射新方法,该法适用于注射液、血清和尿样中FMTD含量的测定.另外,探讨了[Hg(FMTD)(AS)2]的形成对吸收和RRS光谱的影响及引起RRS增强的原因.
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