Traditionally, high performance liquid chromatography (HPLC) and total organic carbon (TOC) analyses are used to verify the effectiveness of industrial cleaning cycles. Using these methods, surface swabs must be examined and analysed in a laboratory in a process that can take up to 48 hours to complete. Such delays significantly reduce the production output of manufacturing units each time a cleaning cycle is required. The new research, which was published in the journal Analytical Chemistry, shows that direct thermal swab analysis using a modified IMS system can achieve industry-accepted detection levels for active pharmaceutical ingredient (API) and cleaning products in a fraction of the time taken by other verification methods. The importance of cleaning manufacturing units between production runs cannot be overstated. With the potency of pharmaceutical products and APIs continuing to increase, the risk to patients posed by contamination events is becoming greater and greater. Producers must therefore find the optimum balance between validating their cleaning efforts and reducing manufacturing downtime. PTEE modification The Lilly team, which was led by Dr Mark Strege, focused on detection of both duloxetine hydrochloride, the API in the antidepressant Cymbalta and the surfactant component of CIP-based industrial cleaning products. The researchers added custom built polytetrafluoroethylene (PTEE) inlet nozzles to a Kaye Validator, increasing the instruments' effective dynamic range to between 5 and 100µg per 25 sq cm This modification brought the detector within the limits demanded by the pharmaceutical manufacturing industry. The authors concluded that use of IMS for swab analysis reduces the risk of false positives and increases the efficiency of the overall process by allowing one sample to be tested for both the API and cleaning product under analysis. They also suggested that, in future, IMS systems that feature an adjustable sample flow controller between the desorber, the ionization chamber and the ionization source would be of particular use in applications in the pharmaceutical industry. Ionization suppression must be considered While the study findings were generally positive, the authors said that the work had highlighted the importance of a implementing a quantitative measure of the effect of ionization suppression when using thermal analysis to examine swabs containing multiple components. For example, it is an accepted practice in the drug industry to include a surface recovery factor to correct for the loss of target compounds when assessing the quantitative recovery of target components from surfaces. The authors suggested that when employing IMS for the analysis of swabs that potentially contain a mixture of components, an "instrument recovery factor" should be considered.