A new and simple differential pulse polarographic procedure was established for the trace determination of mercury(II). An indirect method had to be used since no polarographic peak can be observed for its direct determination. According to their standard potentials, the reaction between SO2− 3 and Hg(II) was suitable. The peak height of sulfite at about –0.70 V (pH 6, 7) was sharp, high, and v...

A method is described for determining low concentrations of hydrogen peroxide by using a polarographic oxygen electrode to measure the oxygen released into solution on addition of catalase. A sample can be assayed directly without prior manipulation in 3 min. The method is capable of assaying hydrogen peroxide concentrations as low as 7 muM. The method has proved extremely useful for the assay ...

An extremely sensitive pulse polarographic method for the determination of zinc dimethyldithiocarbamate (an agricultural fungicide) and zinc di-n-pentyldithiocarbamate (a petroleum additive), has been developed based on the reaction of their dithiocarbamate moiety with copper(II) perchlorate in acetonitrile medium. Well defined diffusion-controlled peaks are observed at –140 mV and –130 mV (vs ...

The extent of inhibition of cytochrome oxidase activity by cyanide depends upon the method of assay. It has been contimed that this inhibition is “readily reversible” with the use of the standard manometric technique. However, in the spectrophotometric assay only about 10% of the control activity is observed after the cyanide is removed by physical methods. The polarographic assay yields interm...

R. BrdiEka, in 1937, in a note to the editor of Nature (1), reported the application of the polarographic method to cancer diagnosis, through the measurement of certain sulphur-containing amino acids present in the proteins in human blood serum. Brdicka made tests on the serum from 67 different persons; 32 of these gave an abnormally low polarographic protein effect. These 32 cases were shown b...

Plasma protein fractions show characteristic differences in their polarographic behavior after being subjected to alkaline digestion. Serum albumin (fraction V) in particular is unique in that it produces a catalytic double-wave in divalent cobalt buffer which increases markedly during the first 10 20 minutes of digestion and then decreases gradually during the following hour. During this same ...

A polarographic method was developed to determine the antineoplastic agent carmustine and other nitrosoureas, such as N-methyl-N-nitrosourea and N-cyclohexyl-N-nitrosourea, in biological fluids at levels well below 1 microgram/ml or g. The stability of carmustine in different media was investigated to prevent losses during administration or assay. Examples of nitrosourea determination in biolog...