Volatile organic compounds (VOCs) are difficult to be eliminated safely and effectively because of their large concentration fluctuations. Thus, maintaining a stable concentration of VOCs is a significant study. In this research, H2O, Tween-80, [Emim]BF4, [Emim]PF6, and [Hnmp]HSO4 were applied to absorb and desorb simulated VOCs. The ionic liquid [Emim]BF4 demonstrated the best performance and was thus selected for further experiments. As the ionic liquid acted as a buffer, the toluene concentration with a fluctuation of 2000-20000 mg.m(3) was stabilized at 6000-12000 mg.m(-3). Heating distillation (90 degrees C) was highly efficient to recover [Emim]BF4 from toluene. The regenerated [Emim]BF4 could retain its initial absorption capacity even after multiple cycles. Moreover, [Emim]BF4 had the same buffer function on various aromatic hydrocarbons. (C) 2019 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.