Sequential injection analysis with dynamic surface tension detection High throughput analysis of the interfacial properties of surface-active samples.
A sequential injection analysis (SIA) system is coupled with dynamic surface tension detection (DSTD) for the purpose of studying the interfacial properties of surface-active samples. DSTD is a novel analyzer based upon a growing drop method, utilizing a pressure sensor measurement of drop pressure. The pressure signal depends on the surface tension properties of sample solution drops that grow and detach at the end of a capillary tip. In this work, SIA was used for creating a reagent concentration gradient, and for blending the reagent gradient with a steady-state sample. The sample, consisting of either sodium dodecyl sulfate (SDS) or poly(ethylene glycol) at 1470 g mol(-1) (PEG 1470), elutes with a steady-state concentration at the center of the sample plug. Reagents such as Brij(R)35, tetrabutylammonium (TBA) hydroxide and beta-cyclodextrin were introduced as a concentration gradient that begins after the sample plug has reached the steady-state concentration. By blending the reagent concentration gradient with the sample plug using SIA/DSTD, the kinetic surface pressure signal of samples mixed with various reagent concentrations is observed and evaluated in a high throughput fashion. It was found that the SIA/DSTD method consumes lesser reagent and required significantly less analysis time than traditional FIA/DSTD. Four unique chemical systems were studied with regard to how surface activity is influenced, as observed through the surface tension signal: surface activity addition, surface activity reduction due to competition, surface activity enhancement due to ion-pair formation, and surface activity reduction due to bulk phase binding chemistry.
Lenghor
Narong
N
Department of Chemistry, Faculty of Science and Institute for Science and Technology Research and Development, Chiang Mai University, Chiang Mai 50200, Thailand.
Grudpan
Kate
K
Jakmunee
Jaroon
J
Staggemeier
Bethany A
BA
Quigley
Wes W C
WW
Prazen
Bryan J
BJ
Christian
Gary D
GD
Ruzicka
Jaromir
J
Synovec
Robert E
RE