GC-MS Determination of 18 Benzene Homologs in Waters of Yangtze River with Separation by Dispersive Liquid-Liquid Microextraction

8.00 mL of the filtered river water sample was taken treated by DLLME with 0.50 mL of acetone (containing 10 μL of Cl2-C=C-Cl2), and the 18 benzene homologs were extracted into the micro-droplets of Cl2-C=C-Cl2 within a few seconds. After centrifugation at high-speed, the extract-phase was separated at the bottom of centrifuging tube. 8 μL of the extract-phase was taken and placed into the sample bottle for GC-MS analysis. The HP-INNOWAX capillary column was used for GC separation and the full-scanning mode as well as the selected ion monitoring mode was adopted in MS determination. Linear relationships between values of peak area and mass concentration of the 18 benzene homologs were kept in ranges within 1 000 μg·L-1. Detection limits(3S/N) found were ranged from 0.055 to 0.156 μg·L-1. Values of recovery found by standard addition method were in the range of 66.5%-106%, with RSD′s (n=5) in the range of 3.1%-8.6%.