Keywords
Citation
(2003), "Freeze drying difficult samples", Pigment & Resin Technology, Vol. 32 No. 5. https://doi.org/10.1108/prt.2003.12932eab.003
Publisher
:Emerald Group Publishing Limited
Copyright © 2003, MCB UP Limited
Freeze drying difficult samples
Freeze drying difficult samples
Keywords: Pumps, Vacuum pumps, Drying
The Welch freeze dryer pump model 8917A-80 is designed for lyophilising samples containing harsh chemicals including strong acids. This rotary vane vacuum pump has an integral oil filtration system for continuous neutralisation of acids and a large oil capacity for increased tolerance to contamination. In addition, Welch Gold oil offers improved resistance to chemical attack. In the past, biological samples were freeze dried with minimal impact on the vacuum pump since water was the primary solvent. Nowadays in laboratories, a vacuum pump is used to handle harsh chemical mixtures – TFA, TFA by-products, acetonitrile, HBr and HNO3, and water – present in samples such as HPLC-prepared and peptide purified materials. The Welch freeze dryer pump helps to prevent rapid oil degradation that can lead to pump failure. The key features that give this vacuum pump its durability and extended maintenance intervals in harsh chemical applications are: integral oil filtration and acid neutralisation system; large oil reservoir for greater contamination tolerance; high purity synthetic Welch Gold oil; cooler oil due to external filtration. With a free air displacement of 173l/min and an ultimate total pressure of 0.2 millitorr, the Welch 8917A-80 vacuum pump is recommended for 12l or smaller freeze dryers. It is compact and portable. Accessories included are an exhaust mist filter and a spanner wrench for removing the oil cartridge. In addition, a charge of Gold oil is supplied.