Simultaneous determination of tartaric acid and potassium in wines using a multicommuted flow system with dialysis

Monitoring of total potassium in winemaking processes using a potentiometric analytical microsystem

Innovation in products and processes, traceability, food security and quality control are inherent challenges in agri-food sector. Trends in wine production are focused on obtaining natural wines with less chemical intervention. Following this goal, a low cost miniaturized, easy-to-use and highly automated microanalyzer to monitor total potassium in winemaking processes is presented. The microsystem monolithically integrates microfluidics as well as a potentiometric detection system and does not require any sample pretreatment. The analytical features provided are a linear range from 250 to 4000 mg L^-1 K⁺, covering all the concentrations expected in must and wine samples, a detection limit of 75 ± 12 mg L^-1 K⁺, and an adequate reproducibility and repeatability. Sample throughput is calculated at 20 h^-1 with a waste volume generation lower than 4 mL per analysis. The microsystem lifetime is at least 4 months. Different wine and grape juice samples have been analyzed reaching outstanding results.

Portable 3D-printed sensor to measure ionic strength and pH in buffered and non-buffered solutions

A miniaturized 3D-printed device has been designed, manufactured and validated to perform as a low-cost sensor for compositional analysis of buffered and non-buffered solutions in industrial or remote areas. The proposed sensor takes advantage of the transport phenomenon and colorimetric measurements. The novel design can simultaneously detect the ionic strength of the solution by measuring the diffusion width of the ions and the pH by image analysis of the pH indicator color change. The results showed that it can detect pH variations of 0.25 and ionic measure difference of 0.1 M in non-buffer solutions. In addition, the design showed its adaptability to be used as a self-referencing sensor. The 3D-printed sensor presented here is not only successful in the evaluation of some important chemical characteristics but also brings flexibility, cost-effectiveness, swiftness and user-friendliness.