Determination of seven polycyclic aromatic hydrocarbons in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet with gas chromatography-mass spectrometry

ObjectiveTo develop a new method for the simultaneous determination of seven polycyclic aromatic hydrocarbons(PAHs)in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet(DLLME-SFO)with gas chromatography-mass spectrometry(GC-MS).

MethodsThe experimental conditions of DLLME-SFO were determined with dodecanol as extractant solvent, methanol as dispersive solvent, inonic strength increased by adding 8% NaCl. After vortexed for 1 min and centrifuged at 4 000 r/min for 5 min, the water sample was cooled down in an ice bath till dodecanol became solid and formed a small ball. Then the solidified dodecanol phase was transferred, and directly detected by GC-MS method after it melted.

ResultsGood linearities were obtained for the seven polycyclic aromatic hydrocarbons within the range of 5 μg/L-200 μg/L. The correlation coefficients were above 0.996. The detection limits ranged from 1.6 ng/L to 3.2 ng/L. The average recoveries ranged from 86.2% to 105% and the RSDs from 3.8% to 9.4%.

ConclusionThe method is sensitive, fast and simple. It has the advantage of little organic solvent consumption, which is friendly to environment and suitable for the detection of seven PAHs in water.