3591.     WAINWRIGHT, H. W., AND LAMBERT, G. I.  Colorimetric Method for the Determination of Thiophene in Synthesis Gas.  Bureau of Mines Rept. of Investigations 4753, 1950, 11 pp.

        Study of the isatin method is reported.  Variables investigated included aging of reagent, temperature, influence of oxidizing agents, and interference due to the presence of CS₂, C₂H₅SH, and olefins.  A procedure was developed for carrying out the analysis, and its applicability to synthesis gas containing low concentrations (less than 2%) of olefins was proved valid.  It is claimed that as little as 0.0001 grain of thiophene S per 54.5 ml. of test reagent can be detected by determining color intensity with a Beckman spectrophotometer at a wavelength of 580 mμ, using a 10-mm. light path.

        WALENDA, H.  See abs. 2687.

        WALKER, J.  See abs. 9, 10.