Smart sensory polymer for straightforward Zn(II) detection in pet food samples

Multi-Spectroscopic Characterization of MgO/Nylon (6/6) Polymer: Evaluating the Potential of LIBS and Statistical Methods

The potential of using laser-induced breakdown spectroscopy (LIBS) in combination with various other spectroscopic and statistical methods was assessed for characterizing pure and MgO-doped nylon (6/6) organic polymer samples. The pure samples, obtained through a polycondensation chemical technique, were artificially doped with MgO prior to analysis for comparative purposes. These artificially doped samples served as crucial reference materials for comparative analysis and reference purposes. The LIBS studies were performed under local thermodynamic equilibrium (LTE) and optically thin plasma conditions. To assess the structural crystallinity of the nylon (6/6) polymer samples, X-ray diffraction (XRD) analysis, and Fourier transform infrared (FTIR) spectroscopy were employed to detect functional groups such as N-H, C-H, and C-N in the adsorbent polyamide nylon sample. Additionally, diffuse reflectance spectroscopy (DRS) analysis was conducted to investigate the effects of doping and temperature on the band gap and material reflectance across different sample temperatures. Chemical compositional analysis was performed using X-ray photoelectron spectroscopy (XPS) with the carbon C1s peak at 248.8 eV serving as a reference for spectrum calibration, along with energy-dispersive X-ray (EDX) analysis, which demonstrated good agreement between the techniques. To validate the different methodologies, the results obtained from CF-LIBS and EDX were compared with those from the standard inductively coupled plasma mass spectrometry (ICP-MS) technique. Finally, for classification analysis, principal component analysis (PCA) was applied to the LIBS spectral data at different sample temperatures (25 °C, 125 °C, 225 °C, and 325 °C). The analyses demonstrated that the combination of LIBS with PCA, along with other methods, presents a robust technique for polymer characterization.

Democratization of Copper Analysis in Grape Must Following a Polymer-Based Lab-on-a-Chip Approach

Quality control in the food industry is of the upmost importance from the food safety, organoleptic and commercial viewpoints. Accordingly, the development of in situ, rapid, and costless analytical tools is a valuable task in which we are working. Regarding this point, the copper content of grape must has to be determined by wineries along the wine production process. For this purpose, grape must samples are sent to laboratories where the copper content is measured usually by flame atomic absorption spectrometry or by inductively coupled plasma mass spectrometry. We herein propose a straightforward, rapid, and inexpensive methodology based both on a film-shaped colorimetric polymer sensor and a smartphone method that at the same time can be used by unskilled personnel. The sensory polymer films change their color upon dipping them on the grape must, and the color evolution is analyzed using the digital color parameters of a picture taken to the film with a smartphone. Furthermore, the analytical procedure is automatically carried out by a smartphone app. The limit of detection of copper of the polymer sensor is 0.08 ppm. Following this approach, 18 production samples coming from the French Groupe ICV company were studied. The copper content of the samples was analyzed by the usual procedure carried out by the company (flame atomic absorption spectrometry) and by the method proposed in this work, ranging this content from 0.41 to 6.08 ppm. The statistical study showed that the results of both methods are fully consistent, showing the validity of the proposed method for the determination of copper in grape must within the frame of wine production wineries and industries.

From Classical to Advanced Use of Polymers in Food and Beverage Applications

Polymers are extensively used in food and beverage packaging to shield against contaminants and external damage due to their barrier properties, protecting the goods inside and reducing waste. However, current trends in polymers for food, water, and beverage applications are moving forward into the design and preparation of advanced polymers, which can act as active packaging, bearing active ingredients in their formulation, or controlling the head-space composition to extend the shelf-life of the goods inside. In addition, polymers can serve as sensory polymers to detect and indicate the presence of target species, including contaminants of food quality indicators, or even to remove or separate target species for later quantification. Polymers are nowadays essential materials for both food safety and the extension of food shelf-life, which are key goals of the food industry, and the irruption of smart materials is opening new opportunities for going even further in these goals. This review describes the state of the art following the last 10 years of research within the field of food and beverage polymer's applications, covering present applications, perspectives, and concerns related to waste generation and the circular economy.