Submicro methods for analysis of organic compounds : The determination of thiol groups

Several methods are described for the determination of thiol groups in organic samples weighing only 50 μg. Iodimetric methods were not widely applicable but the mercurimetric method of fritz and palmer in which thio-Michler's ketone serves as indicator was readily scaled down and gave excellent results (error ± 0.5% absolute) for all compounds tested. Diphenylcarbazone was also tried as the indicator; the procedure was satisfactory for most materials, but some anomalous results were obtained.