This study aimed to describe the adsorption of three pharmaceuticals compounds (ibuprofen, naproxen and carbamazepine) onto natural clay on the basis of equilibrium parameters such as a function of time, effect of pH, varying of the concentration and the temperature. Adsorption kinetic data were modeled using the Lagergren's first-order and the pseudo-second-order kinetic equations. The kinetic results of adsorption are described better using the pseudo-second order model. The isotherm results were tested in the Langmuir, Freundlich and Dubinin-Radushkevich models. The thermodynamic parameters obtained indicate that the adsorption of pharmaceuticals on the clay is a spontaneous and endothermic process.

No abstract

There is a global debate and concern about the use of glyphosate (Gly) as an herbicide. New toxicological studies will determine its use in the future under new strict conditions or its replacement by alternative synthetic or natural herbicides. In this context, we designed biomimetic polymer sensing layers for the selective molecular recognition of Gly. Towards this end, complementary surface acoustic wave (SAW) and electrochemical sensors were functionalized with polypyrrole (PPy)-imprinted polymer for the selective detection of Gly. Their corresponding limits of detection were on the order of 1 pM, which are among the lowest values ever reported in literature. The relevant dissociation constants between PPy and Gly were estimated at [Kd1 = (0.7 ± 0.3) pM and Kd2 = (1.6 ± 1.4) µM] and [Kd1 = (2.4 ± 0.9) pM and Kd2 = (0.3 ± 0.1) µM] for electrochemical and gravimetric measurements, respectively. Quantum chemical calculations permitted to estimate the interaction energy between Gly and PPy film: ΔE = −145 kJ/mol. Selectivity and competitivity tests were investigated with the most common pesticides. This work conclusively shows that gravimetric and electrochemical results indicate that both MIP-based sensors are perfectly able to detect and distinguish glyphosate without any ambiguity.

The structure of microemulsions is of relevance for skin absorption. The water-continuous structures allow faster transport of hydrophilic drugs.

A shear horizontal surface acoustic wave sensor (SH-SAW) operating at 104 MHz was functionalized with a polypyrrole (PPy) molecularly imprinted polymer (MIP) for selective detection of flumequine (FLU) in aqueous media.