The Study And Application Of Microemulsion Liquid Chromatography For Environmental Hormone Analysis

Microemulsion liquid chromatography (MELC) applying a microemulsion as thehigh-performance liquid chromatography (HPLC) mobile phase, was used. The uniquecharacteristics of this method such as selectivity and diversification of adjustable parameters,make microemulsion liquid chromatography has obvious advantage in separation of complexcomponent. In this study, the modifications of the mobile phase to the effect of analysisobjects, included the changes to the type and concentration of surfactant, co-surfactant and oilphase, as well as the pH of the mobile phase and so on. The separation conditions wereoptimized. The main contents of this dissertation were as follows:(1)A rapid and new MELC method has been developed for screening of phenols inenvironmental actual sample. Separations were performed on a cyano column withmicroemulsion as mobile phase, column temperature of35℃, flow rate of1.2mL/min andmeasured wave length of228nm. The mobile phase was1.0g sodium dodecyl sulfate (SDS),7.0mL methanol and91.0mL aqueous HAc-NH4Ac, pH4.0. The results show that: therelative standard deviations of five phenols less than5%(n=7) and a good precision. Thelinear of range for the determination of hydroquinone, resorcinol, o-chlorophenol,p-chlorophenol and2,4-dichlorophenol were0.40~20mg/L,0.63~20mg/L,0.81~15mg/L,0.65~18mg/L and0.69~20mg/L. The detection limits were:0.17mg/L for hydroquinone,0.13mg/L for resorcinol,0.12mg/L for o-chlorophenol,0.09mg/L for p-chlorophenol,0.16mg/L for2,4-dichlorophenol. The method was applied to determination ofhydroquinone, resorcinol, o-chlorophenol, p-chlorophenol and2,4-dichlorophenol in theenvironmental water and disinfectant. The recovery rates of each phenol were97%~101.5%.(2)A novel and simple MELC method has been developed for screening of phthalic acidesters in cosmetics. Separations were performed on a C18column with microemulsion asmobile phase, column temperature of40℃, flow rate of1.0mL/min and measured wavelength of224nm. The mobile phase was4.0g sodium dodecyl sulfate (SDS),12.0mL n-butyl alcohol,1.5mL n-nonane and81.5mL aqueous disodium hydrogen phosphate-potassiumdihydrogen phosphate, pH5.0. The results show that: the relative standard deviations of fivephthalic acid esters less than5%(n=7) and a good precision. The linear of range for thedetermination of DMP, DPP, DBP, DCHP, DOP were0.004~15mg/L,0.005~18mg/L,0.02~20mg/L,0.002~15mg/L and0.26~18mg/L. The detection limits were:0.14μg/L forDMP,0.37μg/L for DPP,0.20μg/L for DBP,0.11μg/L for DCHP,0.30μg/L for DOP. Themethod was applied to determination of DMP, DPP, DBP, DCHP and DOP in cosmetics. Therecovery rates of each phthalic acid esters were97%~102.3%with satisfactory results.(3)Discussed the influence on the structure of microemulsion through the water content,pH and temperature using the conductivity method, combined with chromatographicseparation conditions on chromatographic behavior of five phenols and five phthalic acidesters were further instructions.