Abstract
Nitrophenolic compound are a group of difficulty degraded pollutant. They comes from chemical industry, dyes, agriculture, medicine and other industries. In this study, we choose 4 compound 4-nitrophenol, 2, 4-dinitrophenol, 3-methyl-4-nitrophenol, and 2-methyl-4, 6-dinitrophenol as our analyst which are also list on priority pollutant of the US environmental Protection Agency. Our research group had developed two method—up and down shaker assisted emulsion and water with low concentration surfactant as dispersed solvent-assited emulsion dispersive liquid-liquid microextraction. For the purpose of comparing above two method and applying to varies environmental water sample, we first optimize two methods. Then we apply these two methods to three environmental water samples, river water, lake water and field water, combined HPLC as detector. The part of up and down shaker assisted emulsion, we choose 1-decanol as extraction solvent. Assist emulsion of up and down shaker, we eliminate using organic solvent as disperser. The use of up and down shaker not only decrease harm to environment, also increase convenience to experiment operator. The part of water with low concentration surfactant, we choose 1-octanol as extraction solvent. Mix extraction solvent with 1 mg L-1 Tween 40 150 μL by the use of microinjection needle drawing back and forth four times. Emulsion is complete when we inject above mixture into water sample. This method replaces harmful organic solvent into low toxic and concentration surfactant as disperser. Comparing to shaker-assisted emulsion, this method avoid the time of emulsion. For up and down shaker assisted-emulsion, detection limits in the range of 0.6 – 2.6 μg L-1, precision of the method ranged from 3.0 – 5.0 %. Water with low concentration surfactant as disperser emulsion, detection limits in the range of 0.1 – 1.3 μg L-1, and the precision of the method ranged from 4.4 – 6.0 %. Generally speaking, assist of up and down shaker has better precision, and water with low concentration surfactant assisted emulsion has better sensitivity and lower detection limits.