TurboVap Evaporator

Multi-tube vortexer, VWR N-EVAP evaporator, Organomation Pipets, disposable and volumetric Reservoirs, plastic, 75-mL Robot Coupe vertical cutter/mixer SPE cartridge, silica gel (1-g), J.T. Baker SPE cartridge, Cg (1-g), Varian Teflon stirring bars, VWR TurboVap Evaporator, Zymark TurboVap vessels, 200-mL, Zymark TurboVap vessel support rack, Zymark Visiprep manifold, Supelco... 

Cool the sample extract to room temperature and filter the extract through a Whatman No. 1 (11-cm) filter paper (pre-rinsed with 5mL of acetone) into a filter flask using a Buchner funnel and vacuum (15 inHg). Rinse the boiling flask with 2 x 25 mL of acetone and pass the rinsate through the post-reflux solid and filter paper. Transfer the filtrate into a 200-mL TurboVap vessel. Rinse the filter flask with 5 mL of acetone and add the rinsate to the TurboVap vessel. Concentrate the filtrate to <25 mL (not to dryness) using a TurboVap Evaporator (water-bath at 50 °C increase the pressure up to 30 psi as the volume decreases). All traces of acetone must be removed. 

After the initial extraction with acetone-0.25 N HCl, all traces of acetone must be removed using a TurboVap Evaporator. Traces of solvent can lead to analyte loss through the SPE cartridge(s). 

Lindquist and Dias [26] have described a Zymark Py Technology System which automates and integrates four methods total dissolved sohds (TDS) dried at 180°C, TDS residue on evaporation (TOS-ROE) dried at 103—10S°C, total suspended solids (TSS) dried at 103-10S°C, and total sohds (TS) dried at 103-10S°C. Approved Environmental Protection Agency (EPA) or equivalent methods are used. A TurboVap Evaporator has been incorporated into the design to speed up the sample evaporation. 

Weigh 2.5 or 5 g of crop matrix into a blending vessel. Fortify samples at this point with the appropriate analytical standards. Allow the solvent to evaporate. Add 100 mL of acetone-water (4 1, v/v) and blend the mixture using an Omni mixer equipped with a macro generator for 5 min at 6000-7000 rpm. Filter the sample through a Whatman 934 AFI glass-fiber filter paper on a Buchner funnel/vacuum flask setup. Rinse the blending cup and filter cake with 100 mL of acetone. Transfer the filtrate into a 200-mL TurboVap vessel. 

The solvent was evaporated at 35°C using a turbovap (LV evaporator) under a flow of purified nitrogen. The residue obtained was redisolved in 300 pi of toluene. 

Sample extracts may be concentrated by nitrogen evaporation. Turbovap concentrators direct a steam of nitrogen over the extract surface. Vessels are housed in a temperature-controlled water bath. Although some losses of volatiles occur, this technique is suited to semi-volatile analysis such as DRO. 

Products should be dried quickly after elution, preferably using a high-purity N2 blow-down apparatus, and stored in a freezer. Rotary evaporators using heat and turbovaps using air should be avoided because of the risk of heat decomposition and oxidation or loss by evaporation. 

Sample preparation before HPLC analysis differs for juice and peel oil samples. Juice samples were extracted 1 1 on a weight basis with solvent (10% w/w dichloromethane + 90% hexane) (40 g juice + 40 g solvent), the solvent was separated and evaporated to 0.5 g using a Turbovap 11 model concentration This concentrated mixture was injected into the HPLC. Extraction recovery for the PMFs was determined to be 89 %. Oil samples were diluted to 10% (w/w i in ethanol and injected directly. In both cases, injection volumes of 5 jL were used. All oil samples in this study were winterized for at least 30 days at a temperature of 4 C or less. 

Gas chromatography-mass spectrometer Agilent 7890 GC/5973 MS (Agilent United States), Electric thermostatic drier (Shanghai Yuejin Medical Machinery Factory), Rotary Evaporator Model RotavaporR-200 (BUCHI), Model TurboVap II (Caliper), Ultrasonic cleaner Model KQ-700E (Kunshan Ultrasonic Instrument Co., Ltd.). 

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