Determination of 36 volatile organic compounds in landfill leachate in karst area

The area of karst accounts for about 1/3 of the total area of China, and the amount of groundwater resources account for about 1/4 of the total water resources. Karst groundwater is an important source of water in China, which is also a major source of drinking water in Southwest China.In recent years, with the acceleration of urbanization, the scale of cities has been expanding, the population has been growing, and the living rubbish and waste water generated by urban residents have been constantly increasing. A large amount of waste water and landfill leachate is discharged directly without treatment and infiltrated into the underground through infiltration and burst irrigation, which seriously threatened the quality of underground water resources and the health of people downstream.In this paper, the content of 36 volatile organic compounds (VOCs) in landfill leachate were analysed by method of purge and trap Gas Chromatography-Mass Spectrometry(GC-MS). 5 mL of sample solution was obtained in the purge and trap bottle, and the samples were directly injected using TELEDYNE TEKMAR type purge and trap into the instrument for GC-MS analysis. The samples were separated by DB-VRX GC column, and then detected by the full scanning mode with positive electron ionization. The ion mass were selected and quantified by external standard method. The results showed that, the mass concentration of 36 VOCs was linear with the peak area in the range of 1-100 μg·L-1 . The method detection limit found for 36 VOCs test were in the range of 0.03-0.27 μg·L-1 . The spike recovery were performed by additional mixed standard of 36 VOCs, and the results were in the range of 88% to 110%, with RSD（n=7）ranged from 2.32% to 6.51%.The results showed that a few VOCs were found in the landfill leachate.