A tensammetric study of polyacrylamides, including their determination

Abstract

. 66,2658 (1988). Phase-sensitive tensammetry is shown to be a convenient and useful way to analyse polyacrylamides and associated derivatives (pams) in dilute aqueous solutions. Standard curves were obtained with ranges varying from 9 to 25 ppm and limits of detection varying from 0.7 to 2 ppm. Ways to change the range and sensitivity are discussed and demonstrated. Typical interferences and their effects are tabulated, and the analysis of pams in coal washings is discussed. The analysis of certain mixtures of polyacrylarnides is shown to be possible. Chem. 66, 2658Chem. 66, (1988. On a dkmontrt que la tensamttrie sensible la phase est une mtthode approprike et utile dlanalyser des solutions aqueuses dilutes de polyacrylamides et des dtrivts qui leur sont associks (pams). On a obtenu des courbes standards pour des concentrations allant de 9 a 25 ppm et des L.D.D allant de 0,7 2 ppm. On discute des mkthodes qui permettraient de modifier la limite de dktection ainsi que la sensibilitk et on en fait la dtmonstration. On prtsente un tableau rksumant les interfkrences typiques ainsi que leurs effets et on discute de l'analyse des pams dans les lavages de charbon. On dkmontre que l'analyse de certains mklanges de polyacrylamides est possible.[Traduit par la revue]

Determination of the charge density of acrylamide/acrylate copolymers by tensammetry

“…Tetraalkylammonium ions are known to be strongly adsorbed at a mercury surface, with the tetramethylammonium ion being less strongly adsorbed than the tetraethylammonium (9). Normally, anionic pams are not adsorbed on a negatively charged mercury surface (lo), as is evidenced by their tensammograms being identical to those of the electrolytes at negative potentials (4). Thus the tetraethylammonium ion presumably complexes I tensammogram at the potential at which the capacitive current is 1 PA.…”

“…However, most interferences, including humic acid, can be removed by the various chromatographic processes we developed for cleaning up pam solutions prior to determining concentrations. The procedures are fairly quick and typical interferences and appropriate removal procedures have been described in detail in previous papers (4,5).…”

“…The nmr method is absolute, but not all labs are equipped with a suitable instrument. We have previously shown that the concentrations of solutions of pams can be determined by tensammetry (4) and by the suppression of polarographic maxima (S), and when using either of these methods, it would be convenient if one could further use the same apparatus to determine the charge density of pams of interest.…”

A tensammetric study of the adsorption of cationic polymers and copolymers

“…The tensammograms of large polyelectrolytes do not always exhibit absorption or desorptionpeaks, as their size makes them absorb so strongly that such peaks would be outside the useful 0-2 V potential range. However, their tensammograms are distinctly different from the tensammogram for KC1 alone and the general shape of the tensammograms of anionic and nonionic polyelectrolytes are distinctly different from those of cationic polyelectrolytes (6). Ions such '~u t h o r to whom correspondence should be addressed.…”

“…We have previously shown that we can determine the concentration of polyacrylamides and cationic and anionic acrylamide copolymers using both polarographic maximum suppression (8) and tensammetry (6), and that we can use tensammetry to determine the mol% anionicity of anionic acrylamidelacrylate copolymers after complexation with tetraethylammonium chloride (9). In this paper we compare the tensammetric behaviour of various cationic polymers and copolymers in order to study parameters which affect their adsorption at various potentials.…”