The Applied Research of Liquid-liquid Microextraction in Plant Pigments and Pharmaceutical Analysis
|School||Shanxi Normal University|
|Keywords||Ionic liquids Mixed surfactant Micro-extraction Fe3O4magnetic nano materials Curcumin Doxazosin mesylate (DOX) Spectrofluorometry Spectrophotometry|
Accurate, rapid and sensitive analysis of analytes is the ultimategoal of all analytical methods, thus, the top priority of all methods ishow to improved these indicators. The direct determination oftraditional spectroscopic methods can further improve theaccuracy, while the sensitivity of methods was difficult tomagnitude improvement. Thus, extraction process becomesparticularly important. Ionic liquids and surfactants as extractantfor extraction food coloring and drug, and using spectrophotometryand spectrofluorometry as the means of detection was builded，thismethod can improve the detection sensitivity. In this paper, we areestablished a new detection means use spectra combined withenrichment techniques. The method is simple, sensitive, and has ahigh practical value. There are four parts in this article:1. A simple description for the background and significance ofliquid phase micro-extraction (LPME) here was given, history of the development, the extraction mechanism, analytes, and extractionparameters are also described of its branch (ionic liquid liquid-liquidmicro-extraction and cloud point extraction).2. A new ionic liquid (IL) based micro-extraction method wasdeveloped for the spectrophotometry and spectrofluorometrydetermination of curcumin in curry products. ILs can effectivelyextract curcumin from aqueous solution which were used instead oflarge-scale organic solvents to reduce environmental pollution andproduction cost.[Hmim]PF6can be a good extractant for curcuminin aqueous phase and can be produced the fluorescence enhancemore than10times. Under optimized conditions, the linear equationof Spectrofluorometry was F=8189C(μg/mL)+16.22(R2=0.9995),the fluorescence intensity of curcumin is proportional to theconcentration in the range of0.050ng/mL to120.1ng/mL, and thedetection limit is0.002ng/mL. The linear equation ofSpectrophotometry was A=4.140C(μg/mL)0.0275(R2=0.9997),the Absorbance intensity of curcumin is proportional to theconcentration in the range of18.4ng/mL to494ng/mL, and thedetection limit is6.1ng/mL. Determination of the curcumin contentand product recovery in curry，and the results were satisfactory.3. Lonic liquids was environmentally friendly as an alternative toorganic solvents during extraction. Using [Omim]BF4to extraction the doxazosin mesylate (DOX) in aqueous phase by means offluorescence detection. Under optimized conditions, the linearequation was F=5.7236C (ng/mL)+13.942(R2=0.9995), thefluorescence intensity of DOX is proportional to the concentrationin the range of0.02ng/mL to172ng/mL, and the detection limit is0.0032ng/mL. The recoveries were99.6%,95.8%~99.7%and96.5%~99.3%in tablets, urine and plasma samples, respectively.4. Mixed surfactant that is able to produce a room temperaturecloud point in the presence of NaCl, thus, the mixed surfactant canbe used to extraction the doxazosin mesylate (DOX) in aqueousphase. Fe3O4magnetic nano materials can be used as part of theextractant, and make the two-phase separation to instead of thecentrifugal process. Evaluated the reliability of the method usingspectrofluorometry, and found that the method has the followingadvantages: normal temperature, no need centrifugation, simpleequipment and so on. Under optimized conditions, the linearequation was F=1.392397051C(ng/mL)+89.7515298（R2=0.9993,R=0.9997）, the fluorescence intensity of DOX is proportional to theconcentration in the range of0.04ng/mL to650ng/mL, and thedetection limit is0.004ng/mL. The recoveries were100.96%,96.66%~100.91%and99.37%~99.78%in tablets, urine and plasmasamples, respectively.