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Determination of Penicillamine by Batch and Flow-injection Potentiometry with AgI-based Sensor

Njegomir Radić ; Faculty of Chemical Technology, University of Split, 21000 Split, Croatia
Josipa Komljenović ; Faculty of Chemical Technology, University of Split, 21000 Split, Croatia
Danilo Dobčnik ; Faculty of Chemistry and Chemical Engineering, University of Maribor, 2000 Maribor, Slovenia

Sažetak

Potentiometric determination of penicillamine (pen) is described based on a batch experiment and flow-injection analysis (FIA) using a Chemical sensor with AgI-based membrane. The membrane was prepared by pressing silver salts (AgI, Ag₂S) and powdered Teflon. This membrane was incorporated in a multipurpose electrode body for batch measurements, and in a tubular flow-through sensor body for FIA measurements. For batch measurements, the equilibrium potentials recorded with continuous addition of standard penicillamine solution were considered in relation to lg (c_pen / mol L-1). Linear response with slope of 60 mV was obtained in the concentration range from 2.5 × 10-5 mol L-1 to 1.8 × 10-2 mol L-1.
In using the tubular sensor with a membrane of the same composi-tion for FIA measurements, the linear response with slope of 59 mV was recorded in the concentration range from 1 x 10-4 mol L-1 to 1 × 10-1 mol L-1. The response of the applied Chemical sensor to penicillamine (designated also as RSH) is explained by the formation of sparingly soluble RSAg in the reaction solution and/or on the exposed surface of the sensor. The solubility product K_s(RSAg) was determined using experimental values recorded both by batch measurements and by the continuous-flow experiment. The mean value obtained by different measurements and using a membrane of the same composition is K_s(RSAg) = (1.4 ± 0.1) x 10-20 mol2 L-2.

Ključne riječi

batch potentiometry; flow-injection analysis; membrane electrode; tubular sensors; penicillamine

Hrčak ID:

132094

URI

https://hrcak.srce.hr/132094

Datum izdavanja:

1.2.2000.

Posjeta: 609 *