To clarify the influence of water bath temperature on the decompression and concentration efficiency of a rotary evaporator, accurate control of the water bath temperature is required. Therefore, the water bath temperature control system of a rotary evaporator was studied using the recovery rate of phthalate esters (PAEs) as the indicator. The results showed that when the temperature of the rotary evaporator was set at 40°C, the actual temperature range of the concentrated liquid would change from 26-41 to 39-41°C. By modifying the water bath temperature control system, the recovery rate of PAEs could be increased from 72.4% to 85.6% to 93.2%-98.5%. This test indicates that temperature has a great influence on vacuum concentration, and the recovery rate of PAEs can be improved by modifying the water bath temperature control system used in the rotary evaporator.
Keywords: Phthalate ester; Recovery rate; Rotary evaporator; Temperature.