Theory and Practice of Rapid Flow-Through Analysis Based on Optode Detection and Its Application to pH Measurement as a Model Case

Abstract

Rapid flow-through analysis (RFA) based on optode (optical chemical sensor) detection is proposed, and its performance is discussed using the RFA system equipped with a pH-sensitive optode as a model case. To demonstrate and understand the usefulness of the RFA system, long-lifetime pH-sensitive optodes were prepared using a hydrophilic poly(hydroxyethyl methacrylate) (poly-HEMA) membrane covalently immobilized with a dye containing an amino group such as Congo Red or Nile Blue. The response equation for the optode with the RFA system was proposed, and satisfactory estimation for rapid pH analysis was obtained. The proposed RFA can stand as an advanced method for conventional flow injection analysis.

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

“…Therefore, the necessity to develop new pH sensors is vital to control pH conditions in various environments. Due to their low-cost of manufacturing and maintenance, pH sensors were developed and used for both, clinical and environmental analyses [54][55][56]. Nevertheless, fluorescent pH indicators offer higher selectivity and sensitivity than other classes [28].…”

Development of an Optode Detector for Determination of Anionic Surfactants by Flow Injection Analysis

“…In several FIA systems based on optode detectors, the onechannel FIA system, in which a sample solution is introduced into a flow of a regeneration solution (RS), is used. [21][22][23][24][25][26][27][28] Here, the more standard two-channel FIA system is adopted. Figure 1 depicts the two-channel FIA system, which is made up of two syringe pumps (YSP-101, YMC, Kyoto, Japan), a sample injector, a homemade optode detector, a light source (a tungstenhalogen lamp, LS-1, Ocean Optics, USA), and a fiber-optic spectrophotometer (USB 4000, Ocean Optics, USA) connected to a personal computer (PC).…”

“…In addition, many toxic organic solvents such as chloroform are often used in the methods. Considering the above, there is a need for a simpler method based on chemical sensors such as ion selective electrodes (ISEs), [9][10][11][12][13][14][15][16] optical sensors (optodes) [17][18][19][20][21][22][23][24][25][26][27][28] and fiber optic sensors 29,30 to measure ASs without the use of toxic organic solvents.…”

“…[31][32][33][34][35][36] Several FIA systems based on optode detectors have been reported. [21][22][23][24][25][26][27][28] Therefore, the combination of an FIA system and the optode detector based on L-RB is considered to be a very effective analytical method for determining AS.…”

Design of an optically stable pH sensor based on immobilization of Giemsa on triacetylcellulose membrane

“…Specially, these kinds of sensors suggest many advantages over the traditional systems, because of they offer the capacity of operating in hostile and dangerous environments [1][2][3][4]. The study of these sensors is attractive since they allow us to perform in vivo analysis and in situ monitoring.…”