新型分散液液微萃取-高效液相色谱法检测盐酸利多卡因注射液中2,6-二甲基苯胺杂质

A novel dispersive liquid-liquid microextraction method with high performance liquid chromatography for detection of 2,6-dimethylaniline in lidocaine hydrochloride injection

以正辛醇为萃取剂,六氟异丙醇(HFIP)为分散剂、正辛醇的自组装诱导剂和密度调节剂,建立了基于HFIP-正辛醇超分子溶剂(SUPRAS)的新型分散液液微萃取(DLLME)方法;应用该萃取方法和HPLC-UV法检测了盐酸利多卡因注射液中的2,6-二甲基苯胺(2,6-DMA)杂质。HFIP-正辛醇SUPRAS为反向胶束聚集体结构,且位于体系的下层,因此有利于萃取富集极性较大的2,6-DMA,且可简化萃取操作。在最佳萃取条件(0.4%(v/v)正辛醇,5%(v/v)HFIP,涡旋3 s,静置3 min,以3 000 r/min离心3 min,样品溶液pH 9)下,2,6-DMA的富集因子约为63。在1~100μg/L范围内方法的线性关系良好(R=0.998 9),检出限为0.33μg/L,日内、日间精密度均不高于2.5%,回收率为93.9%~100.8%。新型DLLME方法简便、快速、高效、环保,其与HPLC-UV法结合可定量检测盐酸利多卡因注射液中的2,6-DMA。

A novel hexafluoroisopropanol(HFIP)-octanol supramolecular solvent(SUPRAS)based dispersive liquid-liquid microextraction(DLLME)method was developed for the determination of 2,6-dimethylaniline(2,6-DMA)in lidocaine hydrochloride injection coupled with high performance liquid chromatography-ultraviolet detection(HPLC-UV).n-Octanol was selected as extraction solvent while HFIP was served as dispersing agent,self-assembly inducer of n-octanol as well as density-regulating agent of n-octanol.The HFIP-octanol SUPRAS displays reverse micellar aggregate structures(2-6 pm)with hydrophilic inner cores and is located in the bottom phase of the system after phase separation,which not only facilitates the efficient extraction and enrichment of polar 2,6-DMA,but also simplifies the extraction process.Several parameters influencing the extraction efficiency of 2,6-DMA were investigated and optimized.Under optimum conditions(0.4%(v/v)n-octanol,5%(v/v)HFIP,vortex for 3 s at 60 W,standing for 3 min,centrifugation for 3 min at 3 000 r/min,sample solution pH 9),the novel DLLME-HPLC method shows good linearity for quantitative detection of 2,6-DMA in the range of 1-100 pg/L(R=0.998 9).The limit of detection(LO D)w a s 0.33 pg/L.The enrichment factor(E F)reached about 63.Intra-day and inter-day precisions(n=3)were all below 2.5%.The recoveries were from 93.9%to 100.8%.The results demonstrate that the novel D L L M E-H P L C method is suitable for the accurate quantitative determination of 2,6-D M A in lidocaine hydrochloride injection with advantages of simplicity,rapidness,high efficiency and environmental friendliness,and m a y o w n high potential in future prospects.