Analysis of Six Hydroxylated Polycyclic Aromatic Hydrocarbons in Human Urine by Liquid Chromatography with Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Droplet

KeyWord:dispersive liquid-liquid microextraction based on the solidification of floating organic droplet  liquid chromatography(LC)  hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs)  human urine

Abstract:

      A liquid chromatography with fluorescence detection(LC/FLD) combined with dispersive liquid-liquid microextraction based on solidification of floating organic droplet was developed for the simultaneous analysis of six hydroxylated polycyclic aromatic hydrocarbons(OH-PAHs) in human urine.The important parameters affecting the extraction efficiency,including the type and volume of extraction and dispersive solvents,urine pH value,salt concentration and extraction time were optimized.Under optimized conditions,the urine sample was adjusted to pH 5.0,then enzymatically hydrolyzed and added 20% NaCl to adjust the ion strength.400 ¦ÌL dispersive solvent acetone and 40 ¦ÌL extraction solvent 1-undecanol were rapidly injected into the urine sample.After vortexed and centrifuged at 3 000 r/min for 5 min,the urine was kept in a -20 ¡æ refrigerator for ten min untill the floating organic droplets were solidified and could be easily collected with a spoon into a clean cell bottle.The collected 1-undecanol was injected into LC for analysis after it melted.The results showed that there existed a linear range of 2.5-150.0 ¦Ìg/L for six targeted OH-PAHs in urine with their correlation coefficients(r2) of 0.999 1-0.999 8.The extraction recoveries were in the range of 70.4%-129% with RSDs of 1.7% -14.8%.The limits of detection and quantification were in the ranges of 0.5-1.0 ¦Ìg/L and 1.5-3.0 ¦Ìg/L,respectively.With the advantages of simplicity and rapidness,the developed method could satisfy the requirments for large sample analysis on actual human urine.