Application of a Coaxial-Like Sensor for Impedance Spectroscopy Measurements of Selected Low-Conductivity Liquids

Sensors

Agnieszka Szypłowska¹  Anna Nakonieczna¹  Andrzej Wilczek¹  Bartosz Paszkowski¹  Grzegorz Solecki¹ 

[1] The Bohdan Dobrzański Institute of Agrophysics of the Polish Academy of Sciences, ul. Doświadczalna 4, 20-290 Lublin, Poland; E-Mails:

关键词: trisodium citrate;    aqueous solutions of salts;    food additives;    constant phase element;   

DOI  :  10.3390/s131013301

来源: mdpi

【 摘 要 】

The paper presents a coaxial-like sensor operating in the 20 Hz–2 MHz frequency range used to determine the electrical properties of selected liquids of low electrical conductivity. Examined materials included low-concentrated aqueous solutions of potassium chloride, sodium chloride and trisodium citrate, which are common food additives. Impedance spectra of the measurement cell filled with particular liquids were obtained and analyzed using the electrical equivalent circuit approach. The values of physical quantities and parameters describing the equivalent circuit components, including a constant phase element, were calculated for each sample. The applied sensor was also calibrated for electrical conductivity measurements up to 8 mS/m. The constant phase element parameters differed among the studied solutions and concentrations. This may provide a basis for a detection method of small amounts of compounds, such as food additives in low-concentrated aqueous solutions. To demonstrate the potential of the presented method, samples of purchased mineral water and a flavored drink containing various additives were tested.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.