离子液体双水相萃取荧光法测定维生素B_6

Determination of Vitamin B_6 by Fluorimetry after Aqueous Two-Phase Extraction Based on Ionic Liquid

基于离子液体在盐的作用下能够形成双水相,用于目标物质的萃取,提出了离子液体-硫酸铵双水相萃取、荧光法测定痕量维生素B6的新方法。实验探讨了影响维生素B6萃取率的主要因素,如酸度、萃取剂的用量、时间等。在最适条件下,即λex/λem=342/418nm,pH=8.69,离子液体和硫酸铵的用量分别为1.3mL、2.8g,萃取3min时,体系测定维生素B6的线性范围为1.6×10-7～1.04×10-5 g/L,检出限为4.8×10-7 g/L。

Based on the fact that water-miscible solvent,such as ionic liquid,can be used to form aqueous two-phase system for extraction of analytes in the presence of salts,ionic liquid-salt system of ionic liquid（／Br）and（NH4）2SO4 was developed for the determination of trace vitamin B6 coupled with fluorimetry after aqueous two-phase extraction.Factors that affect the extraction efficiencies of vitamin B6 including pH,the amount of extractant and extraction time were well studied.Under the optimal conditions,i.e.,λex/λem=342/418 nm,pH=8.69,1.3 mL ionic liquid,2.8 g ammonium sulfate and 3 min of extraction,the extraction method presented a linear range of 1.6×10-7～1.04×10-5 g/L with a detection limit of 4.8×10-7 g/L.