Determination of 48 Semivolatile Organic Compounds in Water by Gas Chromatography-Mass Spectrometry with Ultrasonic Assisted Dispersive Liquid-Liquid Microextraction

KeyWord:nitroaromatics  gas chromatography-mass spectrometry(GC-MS)  central composite design(CCD)  ultrasonic assisted dispersive liquid-liquid microextraction(UA-DLLME)

Abstract:

      A gas chromatography-mass spectrometry(GC-MS) with ultrasonic assisted dispersive liquid-liquid microextraction(UA-DLLME) was developed for the simultaneous determination of 15 nitroaromatics,19 anilines and 14 Phthalates in ground and surface water samples.A Plackett-Burman design was adopted for screening of variables such as extractant,disperser volume,extraction temperature,extraction time and ionic strength in order to determine the significant variables affecting the extraction efficiency,which were then optimized by using a central composite design(CCD) and the response surface equations.The optimum experimental conditions were as follows:10 mL water sample containing 2 g/L NaCl was rapidly injected with 0.65 mL acetonitrile(disperser) and 40 ¦ÌL CCl4(extractant),then ultrasonically extracted for 2 min at 40 ¡æ and followed by a centrifugation at 3 500 r/min for 3 min.Results showed that there were good linear relationships for the target compounds in the concentration range of 1.0-200 ¦Ìg/L with their correlation coefficients(r) not less than 0.995 8.The limits of detection(LODs) and limits of quantitation(LOQs) of the method were in the ranges of 0.001-0.030 ¦Ìg/L and 0.004-0.120 ¦Ìg/L,respectively.The average recoveries at low,middle and high spiked levels ranged from 77.4% to 113%,with the relative standard deviations(RSDs,n=6) not more than 9.6%.