Eluent Green – replacing acetonitrile and TFA for fully biodegradable and PFAS-free solvent systems, a paradigm shift toward green LC-MS biopharma analytics

In the advent of ever more restrictive regulations and ambitious sustainability targets, the analytical community faces a critical societal mandate to replace hazardous chemicals in key workflows. Reversed-phase chromatography (RP-LC), the industry workhorse for characterizing (bio-)pharmaceuticals relies heavily on xenobiotic acetonitrile (ACN) and persistent PFAS additives (mainly trifluoroacetic acid, TFA), often considered the gold standard due to their allegedly indispensable characteristics. A sustainable transition requires a full, zero-compromise replacement, without compromising the analytical performance. Meeting these requirements, a novel, green RP-LC-MS solvent system exhibiting the potential for complete substitution is presented. The core innovation is a ternary system based on ethanol/ethyl acetate that solves miscibility limitations combined with cyanoacetic acid as a potent non-PFAS ion-pairing additive. This novel approach delivers outstanding chromatographic resolution and improved MS signal intensities. Eliminating PFAS dependence and removing toxic reagent usage is a timely and necessary step towards sustainable laboratory practices. Adopting this transition, solvent-related CO 2 emissions can potentially be cut by two-thirds, with the components shown to be inherently biodegradable and renewable sourcing also available. With excellent analytical data quality and significantly reduced ecological footprint, this system provides a viable sustainable solution for analytical workflows, with potential also in downstream processing applications.