Research chemist Bill MacCrehan has been with NIST for 44 years, developing new measurement technology for applications as diverse as measuring organomercury in fish tissue, nitroaromatic pollutants in diesel soot, sulfidic compounds in Chesapeake Bay sediments, chlorination products of pharmaceutical compounds in wastewater, vitamins A,E, and K in human serum, organic gunshot residue, trace explosives detection, nanoparticle characterization, and novel materials for bomb dog training. He has been adjunct professor at The George Washington University and University of Maryland and is affiliate professor at Auburn University. He likes boating and riding his motorcycle and has three adult sons – all professionals.