Novel Experimental Approach Developed to Demonstrate Biodegradability Claims for Patented Solvents

BACKGROUND
A client approached us to assist in providing experimental data to substantiate their claim of biodegradability as a USP for their range of patented solvents.

EXECUTIVE SUMMARY
A brainstorming meeting was held with the client to establish their exact requirements and to agree on a joint experimental plan. Since the data was required urgently for presentation at a conference it was important that we delivered first time. This required the team to collect a large amount of data in a short period; extended hours working was required to ensure the collection of relevant time point samples. Microbiological analysis was carried out immediately after sampling at the fully equipped microbiology laboratory at Agenda1, whilst chemical analysis on snap-frozen samples was performed by the client. This two-pronged approach ensured the speedy generation of a reliable data set for the client to incorporate into their conference presentation. A final report was issued which included both graphical and photographic representations of the microbiological data.

OUR APPROACH IN MORE DETAIL
Evolving from more traditional microbiological methods, we developed an approach where we 'contaminated' soil and water samples with working concentrations of the client's solvents, and also a related proprietary solvent for comparison. After the T=0 time point, all samples were incubated at 22.5oC. Sub-samples were then taken at pre-determined time intervals and assessed for bioburden and then immediately snap-frozen in liquid nitrogen for subsequent chemical analysis by the client.

This three day study required two analysts working in tandem over extended working days. The key to the successful delivery of this project was in the planning phase; a dry run of the entire process was rehearsed to ensure that every detail was considered for all experimental steps (e.g., pre-labelled vials, bottles, equipment layout) and that the analysts were clear on co-ordinating their individual roles. This proved particularly important for the first day of the study, with frequent time points over a 16 hour day. A unique sample coding system also had to be devised to permit easy identification of each sample vial by the client against the shipping information.

It was found that all of the client's solvents actually promoted microbiological growth in soil and river water; the timely analysis of the accelerated growth curve identified that further dilutions would be necessary for the later time points. This pro-active treatment of the initial data allowed the dilution step to be modified accordingly for all subsequent time points. As a result, the full three-day data set was captured in the first pass, obviating the requirement for a repeat experiment and saving the client both time and money.