https://hdl.handle.net/10259/9091 Sun, 19 Apr 2026 07:50:12 GMT 2026-04-19T07:50:12Z https://hdl.handle.net/10259/9273 The inversion of multiresponse partial least squares models, a useful tool to improve analytical methods in the framework of analytical quality by design Ortiz Fernández, Mª Cruz; Sarabia Peinador, Luis Antonio; Sánchez Pastor, Mª Sagrario Analytical Quality by Design (AQbD) is the adaptation of Quality by Design (QbD) when it is applied to the development of an analytical method. The main idea is to develop the analytical method in such a way that the desired quality of the Critical Quality Attributes (CQAs), stated via the analytical target profile (ATP), is maintained while allowing some variation in the Control Method Parameters (CMPs). The paper presents a general procedure for selecting factor levels in the CMPs to achieve the desired responses, characterized by the CQAs, when liquid chromatographic methods are to be used for the simultaneous determination of several analytes. In such a case, the CMPs are usually the composition of the ternary mobile phase, its flow rate, column temperature, etc., while typical CQAs refer to the quality of the chromatograms in terms of the resolution between each pair of consecutive peaks, initial and final chromatographic time, etc. The analytical target profile in turn defines the desired characteristics for the CQAs, the reason for the whole approach. The procedure consists of four steps. The first is to construct a D-optimal combined design (mixture-process design) to select the domain and levels of the CMPs. The second step is to fit a PLS2 model to predict the analytical responses expressed in the ATP (the good characteristics of the chromatogram) as a function of the CMPs. The third step is the inversion of the PLS2 model to obtain the conditions necessary to obtain the preset ATP in the corresponding CQAs. The inversion is performed computationally in order to estimate the Pareto front of these responses, namely, a set of experimental conditions to perform the chromatographic determination for which the desired critical quality attributes are met. The fourth final step is to obtain the Method Operable Design Region (MODR), that is, the region where the CMPs can vary while maintaining the quality of the CQAs. The procedure has been applied to some cases involving different analytes, all of which are regulated by the European Union due to their toxicity to human health, namely five bisphenols and ten polycyclic aromatic hydrocarbons. Mon, 02 Oct 2023 00:00:00 GMT https://hdl.handle.net/10259/9273 2023-10-02T00:00:00Z https://hdl.handle.net/10259/9089 Relationships among Hydrogen Peroxide Concentration, Catalase, Glucose Oxidase, and Antimicrobial Activities of Honeys Osés Gómez, Sandra María; Rodríguez, Carlos; Valencia García, Olga; Fernández Muiño, Miguel Ángel; Sancho Ortiz, María Teresa Honey is a natural sweetener made by bees that exhibits antimicrobial activity, mainly related to its H2O2 content. The aim of this work was to research the H2O2 concentration of 24 Spanish honeys from different botanical origins, studying their possible correlation with glucose oxidase (GOx), catalase (CAT), and anti-Staphylococcus aureus activities (minimal inhibition concentration (MIC), minimal bactericidal concentration (MBC), and percentage of inhibition at 5% (w/v) honey against Staphylococcus aureus), as well as possible correlations among all the analyzed parameters. The results showed that the H2O2 concentration did not depend on the botanical origin of the honeys. There were neither correlations between the H2O2 concentration and the activities of GOx and CAT, nor between GOx and antimicrobial activity. However, CAT and antimicrobial activities were positively correlated. Therefore, CAT could be successfully used as a possible marker of the antimicrobial activity of honeys against Staphylococcus aureus. Furthermore, a linear regression model has been fitted to explain the antimicrobial activity from CAT and GOx activity and H2O2 concentration. Although H2O2 is one of the compounds involved in honey’s antibacterial activity, this capacity also strongly depends on other honey components (such as low water activity, acidity, osmolarity, and phenolic compounds). The very high anti-Staphylococcus aureus activity exhibited by all samples could be interesting for commercial honey-based formulations also helping to promote local beekeeping. Mon, 01 Apr 2024 00:00:00 GMT https://hdl.handle.net/10259/9089 2024-04-01T00:00:00Z