Abstract
European Union and United Kingdom regulations promoting the use of more environmentally friendly industrial processes, such as the use of aqueous formulation rather than organic matrices, has facilitated the development of problematic biocontamination events during manufacturing. The current gold standard method of microbial culturing, such as the dip-slide method, of analysing such events have a feedback time of around 48 hours which is not compatible with modern manufacturing processes. The need for a more efficient detection system is profound in order to prevent major industrial losses within the aforementioned time frame.The laboratory-based FlavourSpec® (Gesellschaft fȕr analytische Sensorsysteme mbH (G.A.S.), Dortmund, Germany) with automated sample introduction system (SIS, PAL) and its developed program for the detection of volatile organic compounds (VOCs) was used as the starting point for this method transfer project. The requirement for an at-line continuous monitoring method applicable to industrial set-ups was developed using the information attained from the Flavour-Spec® to transfer to the industrial Gas-Chromatography Ion-Mobility Spectrometer (GC-IMS) instrument using a bespoke design and method for sample inlet. The aim was to provide a rapid detection system of biocontamination events for the monitoring of microbially derived com-pounds (mVOCs). Within the scope of this method transfer study was the investigation and optimization of the G.A.S. developed reference standard ‘Testmix_HS_FlavourSpec®’ which utilizes six ketone and one aldehyde compound.
An optimal internal standard is vital in method transfer procedures to provide a comparable calibration curve across both laboratory and industrial instruments. The current recommended concentrations of the GC-IMS internal standard compounds have been identified as compromising ionisation potential, upon which IMS is dependent for accurate quantification. The optimization of these standard concentrations across both instruments was achieved within this study to pro-vide stability for the ionization potential during subsequent sample analyses.
Further in the procedural documentation of a method transfer is the limit of detection (LOD) to quantify the sensitivity of the instruments utilized for transfer. The ability of detection for both the FlavourSpec® and industrial GC-IMS were determined within this study using the aforementioned internal standard compounds in the ppb/ppt concentration range. The final method on the FlavourSpec® determined LOD values between 0.113ng L-1 for heptan-2-one and 38.3ng L-1 for decanal and the transferred method to the industrial GC-IMS achieved LOD values between 0.133μg L-1 for heptan-2-one and 1.891μg L-1 for decanal.
| Date of Award | 2025 |
|---|---|
| Original language | English |
| Sponsors | KESSII |
| Supervisor | Tony Davies (Supervisor) & Alan Guwy (Supervisor) |