Effects of maxima suppressors on polarographic diffusion currents

Abstract

T he influen ce of maxim a suppressors on the pola rogra phic diffusion current ha s been reillvestigated. Abnormally la rge values for the diffusion current a re foun d i n t he a bse nce of supp ressor . The amou nt required to suppress maxima is less for large electrodes a t lon ger drop-times. The depressive .action of la rge excesses of s up pre ss~r also has been st udied. Agar is shown to be an effective suppressor of maxi ma a nd a suffi Cle nt amo un t can dissol ve in a short. period of t ime, wh~n ~si ng H-?ells containin g agar .plugs! to c~)\npl etel y s upp ress maxima . As a result, quantItative studies of suppresso r a ctlOn with t hiS type of cell are of doubtful signifi cance.

The Effect of Paper on the Detection Limit of Paper-Based Potentiometric Chloride Sensors

“…However, experiments with paper-based devices and samples that contained in addition to KCl also 0.01 wt % gelatin gave LODs that did not differ from experiments without gelatin (see the Supporting Information for full experimental details). As gelatin is well-known to suppress convection, we conclude that convection is not relevant in this system.…”

“…However, experiments with paperbased devices and samples that contained in addition to KCl also 0.01 wt % gelatin gave LODs that did not differ from experiments without gelatin (see the Supporting Information for full experimental details). As gelatin is well-known to suppress convection, 44 we conclude that convection is not relevant in this system. It is interesting to note that for all transducers tested, the standard deviation of the measured EMF was invariably larger at Cl − concentrations below the devices' LOD, as seen in Figure 1B−D.…”

Some factors affecting the precision of polarographic half-wave potential measurements

“…In the determination of the dependence of the halfwave potential on capillary characteristics, the capillaries had mt values of 6.8, 8.8, 10.2, 32, and 64 mg, respectively. The first tID'ee of these were of marine barometer tubing and the last two were of the constricted type described by Taylor and Smith [4].…”

Polarographic Theory, Instrumentation, and Methodology

“…Electrical and mechanical characteristics of the apparatus, such as galvanometer period, may introduce effects of the same order of magnitude as the discrepancies being measured, and migration current must be very carefully eliminated. Maximum suppressors may have a very serious effect on the diffusion current; the general and frequently undesirable effects of maximum suppressors have been discussed by a number of authors (31,195,263).…”