As a well konwn lab instrument manufacturer, we produce and provide rotary evaporator and its supporting equipment : cooling chiller and circulating water vacuum pumps.

Test tools:
DMP, DEHP, DOP, PAEs, ethanol, HPLC, rotary evaporator, K-type metal thermocouple, SHIMADZU LC-20A high performance liquid chromatograph.

The test process uses glassware, avoiding contact with plastic products during the whole process. The glassware is immersed in sulfuric acid-potassium dichromate lotion. After standing for about 4 hours, it is rinsed with tap water, pure water, and chromatographic grade acetone. Bake in an oven at 240 ℃ for more than 6 hours.

Test conditions:
Standard solution preparation and concentration, select three representative PAEs components DMP, DEHP and DOP for testing.The PAEs standard stock solution was prepared with methanol and stored at 4℃ in the dark. In the recovery rate test, a standard solution with a mass concentration of 2 μg/mL was added to pure water, referring to the USEPA3510c [16] method, using 70 and 50 mL dichloromethane for liquid-liquid extraction twice, and the combined extracts were concentrated by a rotary evaporator The organic phase was made up to 20 mL with dichloromethane, then evaporated to dryness with nitrogen at 35 ℃, and then made up to 1.5 mL with chromatographic grade methanol to be tested.

Test the temperature in the distillation flask during the vacuum concentration process Put the K-type cheap metal thermocouple into the distillation flask to test the temperature of the concentrated liquid. Add the dichloromethane extract of PAEs to the distillation flask and concentrate under reduced pressure. Operate according to the instrument manual. After the system is equilibrated, start to record the temperature of the concentrated solution in the distillation flask. Record every 2 minutes and continuously record for 30 minutes.

Reconstruction of the water bath temperature control system The water bath temperature control system of the rotary evaporator was remodeled. The control temperature was set to 40°C, and the dichloromethane extract of PAEs was added to the distillation flask to concentrate under reduced pressure.

PAEs analysis and detection PAEs are analyzed and detected by high performance liquid chromatography (HPLC), and the test conditions are: column Diamonsil C18 (4.6 mm × 250 mm × 5 μm, Dima); column temperature 35 ℃; methanol-water binary Gradient mobile phase: 0 ～10.5 min 75% (V: V) methanol, 15 min to the end of 100% methanol; detection wavelength 228 nm; injection volume 20 μL; flow rate 1.0 mL/min.