| Although VK3 has a conjugated planar structure, it is not naturely fluorescent. VK3 can be reduced fluorescent,then be determined by fluorecent method. In this paper, fluorecent meropenem is also been determined in micellar medium by spectrofluirimetry. The central content of this paper is following:1. Vitamin K3 (VK3) is not naturally fluorescent but yields fluorescence when it is reduced by TiCl3 solution at acid medium. All fluorescence measurements are performed atλex=330nm andλem=444nm. The calibration curve has a linear range 8.0×10-7～1.60×10-5 mol / L ( R=0.9987)and a detection limit of 8.45×10-9 mol/L.The recoveries vary between 98.6～102%.2. Vitamin K3 (VK3) yields fluorescence when it is reduced to by L-Cys. All fluorescence measurements are performed atλex=389 nm andλem=520nm.The calibration curve has a linear range 3.2×10-7～8.0×10-5 mol/L ( R=0.9994)and a detection limit of 1.2×10-9 mol/L. The average recovery is 98.2 %.3. Vitamin K3 (VK3) yields fluorescence when it is reduced by hydrazine sulfate(HS). However, it is possible to produce much stonger fluorescence when complexed withβ-cyclodextrin (β-CD). 1:1 stoichiometry of the complex was established and its association constant was calculated by a nonlinear regression method. The complex had excitation and emission maxima at 326 and 415nm respectively. The best limit of detection 6.63×10-9 mol/L and limit quantification 2.14×10-8 mol/L were obtained in presence ofβ-CD in acidic media(pH=4.07). The recoveries achieved in all cases varied between 99.5% and 102%.4. The spectrofluorimetric determination of meropenem was studied by adding surfactant (CTMAB), which enhanced the fluorescence of meropenem. The optimum experimental conditions were investigated. A new micellar enhanced spectrofluorimetric method for determinating meropenem was developed. A linear relationship is between 5.07×10-7-5.07×10-5g/mL, the detection limit is 2.95×10-8g/mL. The method can be applied to the determination of meropenem in medicine with satisfactory results.
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