Analyzing Pharmaceutical Process Tank Residues
Genetic Engineering & Biotechnology News - August 1, 2014
After routine cleaning of metal or glass surfaces of pharmaceutical process tanks, residues may remain and appear as faint whitish or dark stains that cannot be easily wiped off. To clean the residue without damaging the tank surface, it is necessary to identify the residue so that the correct solvent or cleaning method can be used.
Due to the small amount of residue on the tank surface, it can be difficult to obtain a large enough sample volume for analysis. For unambiguous identification of the residue, it is desirable to remove a pure sample from the sampling tool for analysis, without any attached material from the sampling tool.
White cotton or polyester swabs are common sampling tools, sometimes soaked in water or alcohol prior to wiping the tank surface. Swabs are poor sampling tools because only a small amount of residue is transferred to the swab, the material of interest is difficult to remove from the swab for analysis, and light-colored residues cannot be seen on the white swab.
Our objective was to develop an alternative sampling method to obtain a larger volume of residue that could be easily isolated for micro-analysis to identify organic components by FTIR (Fourier Transform Infrared Spectroscopy), or EDS (Energy Dispersive X-Ray Spectrometry) to identify inorganic components.