Potassium-selective electrodes based on macrocyclic polyethers

Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 2. Ionophores for Potentiometric and Optical Sensors

“…However, most of the selectivities of those ISEs were not very different from those of ionophore-free ion-exchanger membranes (e. g. best attained log −1.8). , Also, rather poor selectivities (log (FIM): −0.4) were obtained in a more recent investigation on 18-crown-6 covalently attached to poly(acrylic acid), which was then incorporated into a PVC matrix , 20 crown compounds with 5−12 ether oxygens were tested with a special view to their selectivity for K + over Na + (for the characterization of some similar ionophores see also a more recent investigation). The highest selectivities were obtained for the two dibenzo-30-crown-10 derivatives K + -7 and K + -8 ( K + -7 , log (FIM): 342 −2.7; dipentyl phthalate), which owing to their flexibility and large size were suggested to be able to wrap around K + .…”

“…Similarly, dinaphtho-30-crown-10 ( K + -9 ) also gave a fairly high selectivity (log (FIM): −3.0; oNPOE, KTpClPB) (FIM): −2.6; dipentyl phthalate), whereas dibenzo-18-crown-6 and dicyclohexyl-18-crown-6 seem to be too rigid to accommodate the cation optimally. , On the other hand, the very similar ionophore 4‘-picrylamino-5‘-nitrobenzo-18-crown-6 ( K + -11 ), which had been developed as a chromogenic polyether reagent for spectrophotometric determinations following solvent extraction, gives only a modest selectivity when incorporated into oNPOE (log (SSM): −1.8 to −0.3; KTpClPB) …”

Electrochemical method for measuring C-reactive protein using crown ether-phosphate ester ionophores

“…Preparation of 4-(Bromomethyl)benzo-15-crown-5. Methylbenzo-15-crown-5 was prepared from 4-methylcatechol and tetraethylene glycol dichloride according to the procedure used by Petranek and Ryba (12). A typical bromination of the crown ether proceeded as follows: 0.7 mmol of 4-methylbenzo-15-crown-5 and 0.7 mol of n-bromosuccinimide were dissolved in 40 mL of dried CC14 and stirred for 5 min under N2.…”

Potentiometric selectivity study of crown ethers containing four ring oxygen atoms and benzoxymethyl or carboxylic acid side chains as ionophores for lithium and potassium

“…tion [27], and the composition of the extracting or membrane matrix (23, 24, 30, 331. Flow injection analysis has been employed in potentiometric selectivity studies of crown ethers and other neutral ionophores for certain metal ions. It offers a fast, efficient, and economical means of measurement, in addition to the capability of incorporating a series of different electrodes in the flow cell [19, 28, 30, 32-34J. I n this study, flow injection analysis is used t o study the potentiometric selectivities of five crown ethers with four ring oxygen atoms and different types of pendant groups toward alkali and alkaline earth metals; the results are compared with those of previous solvent extraction studies.…”