Tubular detectors for flow-injection potentiometric determination of tetrafluoroborate in electroplating baths

✍ Scribed by A.N. Araújo; M.B. Etxebarria; J.L.F.C. Lima; M.C.B.S.M. Montenegro; R. Pérez Olmos

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 607 KB
• Volume: 293
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)00073-5

✦ Synopsis

AbStlWt

PVC tetrafluoroborate tubular electrodes without an inner reference solution, based on tetraoctylannnonium as the ion exchanger and 2-nitrophenyloetyl ether as the mediator solvent, were constructed. The general operating characteristics of the tubular detectors were evaluated by a single line flow-injection system with low sample dispersion and compared to those of corresponding conventionally-shaped electrodes, determined in batch conditions. In flow-injection analysis (FIA), the detector response was linear in the concentration range between 4 x 10m6 and 10-l M, with a mean slope of 59.2 f 0.9 mV/dec in the pH range between of 2.7 and 11.5. The reproducibility of the detector potentials was approximately 0.2 mV during a day of continuous operation. The membrane used showed a high degree of selectivity. The tubular detectors remained operational over a long period of time (approximately 36 months) and had a response time that enabled a sampling rate of 360 h-l. The electrodes were later used in the determination of tetrafluoroborate in concentrated electrolytic baths for which a high dispersion FL4 system was developed. The analyses of seven baths with different compositions presented results with mean recovery values of 98.8% with a coefficient variation of 1.9%.