Ion-selective electrodes in drug analysis (A review)

Abstract

Progress in the pharmaceutical industry results in the creation of a great number of drugs including substances of various structures and compositions, differing in their pharmacological action and therapeutic properties [I].This situation poses a problem of controlling not only the quality of drugs but the content of drugs (and their metabolites) in various media as well, including biological liquids of the human and animal organism, food products, waste waters of pharmaceutical plants, etc. [2].Potentiometry with ion-selective electrodes (ISE) is still one of the most promising analytical tools capable of determining both inorganic and organic substances in medico-biological practice [3]. Applications of the potentiometry techniques in pharmaceutical analysis and clinical chemistry were reviewed in [4 -8]. There is a constant increase in the number of electrodes capable of selectively identifying various drugs.Below we will summarize the data published between 1988 -I996 on the use of ISE for the purposes of drug analysis.The potentiometric determination of drugs can be based on either direct potentiometry or potentiometric titration. The detection is performed with the aid of transducers, sensitive to either inorganic or organic ions, including biosensors. A large number of biosensors now have been described [9], which are applicable to pharmaceutical and clinical analyses. However, we will concentrate mostly on the potentiometric methods of drug analysis using ISE for inorganic and organic ions.

Solid Electrodes in Electroanalytical Chemistry: Present Applications and Prospects for High Throughput Screening of Drug Compounds

“…Ion selective electrodes (ISEs) belong to the oldest established chemical sensors. Their response characteristics including selectivities, kinetic process and basic thermodynamic process [10,[250][251][252][253][254][255][256][257] are comparatively well understood. ISEs are mainly membranebased devices, consisting of permselective ion-conducting materials, which separate the sample from the inside of the electrode.…”

“…This practice clearly favors the occurrence of cotransport and thus brings about a less than optimal detection limit. The composition of the membrane is designed to yield a potential that is primarily due to the ion of interest via selective binding processes [10,[250][251][252][253][254][255][256][257][258][259][260][261]. In addition, the membrane backside is usually contacted with a relatively concentrated internal filling solution of a primary ion salt.…”

“…On the inside is a filling solution containing the ion of interest at a constant activity. The membrane is usually water insoluble, nonporous and mechanically stable [10,[250][251][252][253][254][255][256][257][258][259][260][261]. ISEs membranes always contain a substantial concentration of the primary ion salt, which is typically in the mM range.…”

Surface morphology changes of polymer membrane and carbon paste sertraline sensors

“…Ion-selective sensors have been used for analytical determination of a wide variety of pharmaceutical compounds [8][9][10]. They have replaced other analytical methods due to their utility and simplicity.…”

Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with carbon nanotubes as ion-to-electron transducer in polymer membrane-based potassium ion-selective electrodes

“…Potentiometric ion sensors, or ion-selective electrodes (ISEs), are the most frequently used chemical sensors in analytical applications in medical, environmental, and industrial analysis [1][2][3][4]. As an analytical device, ISE offers many advantages such as selectivity, fast response, simple analytical procedure, and relatively low cost.…”