Evaporators and Evaporation Systems
Top 5 Signs That You Should Service or Replace Your Nitrogen Evaporator
- It uses a water bath vs. a dry heat block. Water baths can cause contamination by condensing evaporate from the water bath on the lid and dripping into your sample.
- Evaporation rates are getting longer. This could be a sign of cracked or damaged nitrogen hoses or gaskets. It could also indicate a heater problem.
- A sample temperature probe is not available. Temperature probes read actual sample temperature during evaporation. Without it, samples could overheat, causing degradation and damage to the sample.
- Too much nitrogen is being used. There could be a leak in the nitrogen line or in the system, wasting valuable nitrogen.
- The evaporator is no longer reliable. Inconsistent evaporation rates from run to run could indicate service issues that could be costly to fix.
Top 5 Signs That You Should Service or Replace Your Vacuum Concentrator
- Refrigeration of samples during evaporation is not available. Heat sensitive samples, such as protein and RNA can be ruined if they are overheated. A vacuum evaporator with controlled cooling is required.
- The concentrator takes up a lot of space. Newer concentrators are as small as a 9” cube and others include the concentrator, cold trap and pump in one box. A floor model option houses the vacuum pump and doesn’t take any bench space.
- Your application has changed. The vacuum concentrator was intended for aqueous samples, but now solvents or acids are used. Corrosion of key components, including the chamber, lid and rotor hub, could affect the concentrator’s ability to evaporate or even operate.
- The unit no longer pulls a good vacuum. Gaskets, hoses and all rubber components break down over time, causing a decrease in depth of vacuum resulting in longer evaporation times.
- The evaporator is no longer reliable. Inconsistent evaporation rates from run to run could indicate service issues that could be costly to fix.
Top 5 Questions You Should Ask When Buying An Evaporator or Evaporation System
- What are your sample sizes? Microtiter plates and micro centrifuge tubes work best in a centrifugal vacuum concentrator. For large samples up to 450mls, a vortex evaporator is recommended.
- What are your samples? Acids require an acid-resistant system. Solvents damage plastic and rubber components, an appropriate system to prevent damage is recommended. A -50C cold trap is ideal for aqueous-based samples, a -85C cold trap traps most solvents and a -105C cold trap is recommended for alcohols.
- Are your samples heat sensitive? Even at ambient set point, vacuum concentrators add heat through friction. A concentrator that has refrigeration built into it will give you the temp erature control recommended to maintain the viability of heat liable samples.
- Do you have limited space? A floor model with casters or small all-in-one benchtop model can be moved out of the way when not in use.
- Do you prefer vacuum evaporation or nitrogen blow-down? Some samples require evaporation under nitrogen, which is gentler, for volatile solvents.
Article courtesy of Lab Manager Magazine
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