With the MultiVap concentrators of LabTech, based in Italy, it is possible to evaporate solutions to solid state or a fixed end-point volume without the use of vacuum and high temperature. During the operation, these instruments accelerate the evaporation of the solvent by decreasing its partial vapor pressure just above the surface of the liquid. The MultiVap concentrators use blowdown technique to remove the gas layer that is saturated with the solvent vapor. Because the inert gas stream seizes the solvent molecules that pass into the gas phase, they cannot return into the liquid phase. The removed particles may be replaced by newer and newer solvent molecules, thus increasing the rate of evaporation. The blowdown technique is excellent for evaporating smaller sample volumes between 2 and 200 ml. With higher volumes, there is a risk of loss of volatile components due to the longer concentration time. In LabTech sample evaporators, the evaporators are housed in a temperature-controlled water bath or aluminum block, even in this way increasing the rate of concentration.
MultiVap 10 – 10-position automated sample concentrator
The MultiVap 10 sample concentrator supports 10 samples and is capable of evaporating a maximum of 50 ml or 200 ml solution in tubes with concentration zone or in tubes for dry evaporation. The 5-5 evaporator tubes arranged in two rows can all be of the same volume (50 ml or 200 ml) or different due to the spacers that can be easily installed and removed. The MultiVap 10 uses the vortex gas injection technique, which can keep the entire solution in a spatter-free stirring, therefore, the dissolved sample does not collect on the wall of the sample tube but at the bottom of it. When using tubes with concentration zone, a laser sensor monitors the reaching of a final volume of 0.5 ml or 1 ml at each evaporating place. The distance of the nozzles from the evaporator tube wall and their angle of inclination can be adjusted manually row by row. The evaporator tubes immerse into a water bath whose temperature can be controlled between room temperature and +70°C. The instrument is controlled by a touch screen, on which the following parameters can be set: the used positions, the gas pressure, the temperature and time. The gas blowing can be switched on and off individually. The evaporation can be stopped with endpoint detection per tube or after a specified time or with endpoint detection + after a specified time or manually. If the set conditions are met, the end of the evaporation is signalled and the nitrogen blowing is stopped. The large tube diameter also facilitates the rapid evaporation.
The Teflon-coated water bath tank with its on-off lighting and its transparent window allows the observation of the samples during the evaporation. The tank is equipped with a quick-connect drain plug for convenient emptying. Unused evaporator positions can be covered with hole caps to prevent evaporation. The removal of the generated solvent vapors from the instrument is ensured by a built-in extraction system. To drain the vapors, the instrument must be placed in a fume hood or the approximately 3-meter-long hose (delivered with the instrument) must be connected to the laboratory exhaust system.
- temperature range: room temperature -70 °C
- required gas pressure: 5-8 bar
- gas consumption in case of 10 positions max. 60 liter/minute
- water tank volume: 10 liters
- dimensions: 70 x 45 x 67 cm (W x D x H), 38 kg