Qingfen Liu

Partitioning Behavior of Penicillin G in Aqueous Two Phase System Formed by Ionic Liquids and Phosphate

Abstract An aqueous two‐phase system (ATPS) was presented with hydrophilic ionic liquid 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl) and NaH2PO4 aqueous solution in this paper. The partitioning behavior of penicillin G in the ATPS was investigated. Concentrations of NaH2PO4, penicillin G, and [Bmim]Cl were evaluated to determine their effects on the partition coefficient and extraction yield of penicillin G. It was found that both of partition coefficient and extraction yield strongly depended on the concentration of [Bmim]Cl, penicillin and NaH2PO4. A high extraction yield of 93% was achieved with the following parameters: NaH2PO4 · 2H2O 40% (wt%), penicillin 45000∼50000 u/ml, [Bmim]Cl 20∼21% (wt%). The [Bmim]Cl/NaH2PO4 system was also applied in a real filtration of penicillin G fermentation broth and the extraction yield was averaged at 91.5%. It is worthy noting that the working pH value of ATPS was at the range of 5∼6, no emulsification and protein denaturation could be observed.

Desulfurization of Diesel Fuel by Extraction with Lewis-Acidic Ionic Liquid

Abstract Ionic liquids were found to be highly selective for the extractive removal of aromatic sulfur compounds from fuels at room temperature. The efficiency of ionic liquids for the removal of aromatic sulfur compounds is dependent on the properties and structure of the ionic liquids. In this work, the Lewis-acidic ionic liquid 1-butyl-3-methylimidazolium tetrahalogenoferrate(III) ([BMIM] [FeCl4]) was synthesized and demonstrated to be more effective for the removal of aromatic sulfur compounds from diesel over ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] [BF4]) because of its Lewis-acidic property. The ionic liquids favorably extracted organic compounds with a higher density of aromatic π-electrons. [BMIM][FeCl4] ionic liquid can be regenerated through reextraction by hexane, and could be used in multiple steps for the removal of sulfur compounds from diesel.

Analysis of Mogroside V in Siraitia grosvenorii with Micelle-mediated Cloud-Point Extraction

INTRODUCTION Mogroside V is the main effective ingredient of Siraitia grosvenorii used as a natural sweet food as well as a traditional Chinese medicine. The sample pre-treatment prior to chromatographic analysis requires large amounts of toxic organic solvents and is time consuming. OBJECTIVE To develop an effective and simple method for extracting and determining mogroside V of Siraitia grosvenorii. METHODS Mogroside V was extracted and preconcentrated by micelle-mediated cloud-point extraction with nonionic surfactant isotridecyl poly (ethylene glycol) ether (Genapol® X-080). The obtained solutions containing mogroside V were analysed by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. The chromatographic separation was performed on a C18 -column using gradient elution with acetonitrile and water at 203 nm. RESULTS The cloud-point extraction yield was 80.7% while the pre-concentration factor was about 10.8. The limit of detection was 0.75 µg/mL and the limit of quantification was 2 µg/mL. The relative standard deviations for intra- and interday precisions of mogroside V were less than 8.68% and 5.78%, respectively, and the recoveries were between 85.1% and 103.6%. CONCLUSION The HPLC-UV method based on micelle-mediated cloud-point extraction for determination mogroside V in Siraitia grosvenorii was environmentally friendly, simple and sensitive.