Homebuilt cost-effective nitrogen blowdown evaporator

Nitrogen blowdown evaporation (NBE) is a widely used technique for solvent removal. It is explicitly called for in the procedures for a wide range of analytical methods developed by regulatory and scientific agencies, and stands as a valuable tool in the sample preparation toolbox. However, commercially available equipment to perform NBE can be quite expensive, especially while working through different approaches to sample handling in the early stages of a research or analysis project. This paper details the design and construction of a homebuilt nitrogen blowdown evaporator with conventional and low-cost materials and processes, coming in at ∼20% the cost of commercial equipment. A proof-of-function experiment was carried out using the apparatus to evaporate a solution containing three per- and polyfluoroalkyl substances (PFAS). This study showed that: (1) the careful selection of materials in the design of the apparatus avoided detectable background contamination; (2) the apparatus functioned with little to no analyte loss (recoveries of 99-100% after blowdown and solvent reconstitution); and (3) evaporation times compared favorably with other designs and applications of NBE hardware. Adaptations of the apparatus for different sample containers are discussed. The ESI† includes plans and detailed instructions for the assembly and operation of the apparatus.