Ammoniacal silver nitrate (10 mg/ml) was added to terminate acetylene reduction assays used to measure nitrogenase activity. Silver nitrate quantitatively precipitated acetylene as the carbide salt, but did not affect the ethylene formed. The vials containing ethylene can be analyzed gas chromatographically at the rate of about 13 samples in 10 min
K. A. V. David, Apte, S. K., Banerji, A., and Thomas, J., “Acetylene reduction assay for nitrogenase activity: gas chromatographic determination of ethylene per sample in less than one minute”, Applied and environmental microbiology, vol. 39, pp. 1078–1080, 1980.