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Coupled cation exchange reactions

Meyerhoff and Rechnitz (1976) developed a potentiometric creatinine sensor by inclusion of creatinine iminohydrolase between the gas-permeable membrane of an ammonia electrode and a dialysis membrane. Since the specific activity of the enzyme used was very low, 0.1 U/mg, only 43 mU could be entrapped at the electrode. Therefore the sensor was kinetically controlled and reacted to addition of the enzyme activator tripolyphosphate by an increase in sensitivity from 44 mV to 49 mV per concentration decade and a corresponding decrease of the detection limit. These effects agree with theoretical considerations of reaction-transport coupling. The samples were treated with a cation exchanger to remove endogenous serum ammonia. [Pg.175]

The deposition also occurs onto more neutral fibers [73], Therefore Laughlin suggested an ion exchange reaction between the counterions of cotton carboxyl groups and the cationic salts, coupled with physical adsorption [26],... [Pg.535]

SD = self-diffusion, TD = tracer diffusion, CR = chemical reaction (e.g. recrystallization, cation exchange, etc.), CR(SD) and SD(R) refer to a coupled process where rate data are given for first mentioned process, ( ) refers to case where there is uncertainty as to the controlling mechanism. [Pg.214]

Synthesis of the modified triphosphate subunit was accomplished starting from ethyl bis(bromomethyl)phosphinate 253 (Scheme 51). An Arbusov reaction with triethyl phosphite and trimethyl phosphite, respectively, produced bis (phosphonomethyl)phosphjnate 255 in 40% overall yield. A selective monodemethylation by cyanide and acidificaticHi led to monophosphonic acid 256. Bismethylene triphosphate (BMT) 258 analogues of nucleosides were obtained by coupling of the 5 -free OH nucleosides 257 with phosphonate 256 under Mitsunobu conditions [181,182]. TMSBr mediated deprotection followed by treatment with aqueous anmumia and cation exchange afforded bismethylene analogues 259 of nucleoside triphosphate in yields up to 62%. [Pg.93]


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See also in sourсe #XX -- [ Pg.193 , Pg.196 ]




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Cation coupling reactions

Cation exchange

Cation exchange reactions

Cation exchangers

Cationic exchangers

Cationic reactions

Cations cation exchange

Exchangeable cations

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