Quantitative Structure Retention Relationship Models in an Analytical Quality by Design Framework: Simultaneously Accounting for Compound Properties, Mobile-Phase Conditions, and Stationary-Phase Properties

Abstract

Quantitative structure retention relationships (QSRRs) can play an important role in enhancing the speed and quality of chromatographic method development. This paper presents a novel (compound-classification-based) QSRR modeling strategy that simultaneously accounts for the analyte properties, mobile-phase conditions, and stationary-phase properties. It involves the adoption of two models: (A) partial-least-squares discriminate analysis (PLS-DA) to classify compounds into subclasses having similar interactive relationships between the mobile-phase conditions and stationary phase; (B) L partial least squares (L-PLS) to predict the compound's retention time based on the mobile-phase conditions, stationary phase, and compound properties. For the retention time of a compound to be modeled, the most favorable compound class is identified in an optimization framework that simultaneously minimizes both the compound misclassification rate (based on PLS-DA) and the retention time prediction error (based on L-PLS) through a mixed-integer optimization. The proposed QSRR model (L-PLS with compound classification) significantly improves the retention time predictability compared with traditional QSRR or L-PLS models without compound classification. When combined with the linear solvation energy relationship parameters (using Abraham coefficients) as the column properties, the approach allows the following: (1) prediction of (new, never analyzed) compound retention times under chromatographic conditions (columns and mobile-phase conditions) used to train the model;(2) prediction of (previously analyzed under training conditions) compound retention times under chromatographic conditions that have not been previously evaluated; (3) optimization of the chromatographic conditions (mobile-phase and column selection) to maximize critical pair resolution, including new compounds; (4) enhanced mechanistic understanding of the interactive retention relationship between compounds, the mobile phase, and the column (e.g., compound retention mechanism). The effectiveness of the proposed modeling strategy will be demonstrated through two practical pharmaceutical applications in supercritical fluid chromatography and reversed-phase liquid chromatography.

Teachers’ Strategies for Managing Adolescent Students with Maladaptive Behaviours in Senior High Schools in Offinso Municipality

“…However, the teachers did not observe much ofmaladaptive behaviours such obsessive compulsive behaviour, psychotic disorder or the students bringing noisy electric devices into the classroom.These responses were 88.8% reliable for policy and resources allocation and they varied significantly between the teachers and across the three schools. These findings affirmed the results of Cain and Pincus (2016), Ali et al (2014) and Muteki et al (2013) and supported by the rational emotive theory, behavioural theory and BF Skinner's theory.…”

“…These behaviours conforms to the results on this study are they fall under truancy, delinquency, unfriendly behaviour, bipolar disorder and psychotic disorder. Similarly, these findings conform to Muteki et al (2013) who noted that unsocial, withdrawn, unhappy, depressed, fearful and nervous do attract very little attention to themselves were very common maladaptive behaviours of students. The Factors Influencing Maladaptive Behaviour in the Students It can be observed in table 4 that the teachers believed that parental attitude, poor parental control, influence of media, influence of social clubs, autocracy of school leadership, injustice in school management and autocratic leadership of teachers are the most prominent factors influencing maladaptive behaviour among the students of the three schools in the circuit.…”

“…It was further underpinned by BF Skinners theory, social learning theory and Behavioural theory. The finds were similar to that of Ugwu (2017), Muteki et al (2013) and varied slightly from the findings of Glozah and Pevalin (2014) Recommendations For policy implications, management of the three schools in the Offinso Municipality should commit more Journal of Education and Practice www.iiste.org ISSN 2222-1735 (Paper) ISSN 2222-288X (Online) Vol.11, No.10, 2020…”

“…However, Ugwu further noted there was no significant difference between male and female students on the causes of maladaptive behaviour. Muteki et al (2013) also identified unfulfilled or thwarted psychosocial needs as a lead cause of maladaptive behaviour in adolescent student.The findings of Glozah and Pevalin (2014) on the other hand was much similar to that of this study. Glozah and Pevalin found adolescents' family background characterized by frequent fighting between parents, lack of parental love and affection, divorce and different forms of deprivations including psychological and materials could lead to maladaptive behaviours strongly influenced maladaptive behaviour.…”

A Systematic AQbD Approach for Optimization of the Most Influential Experimental Parameters on Analysis of Fish Spoilage-Related Volatile Amines

“…All of them contribute to the overall knowledge of the method and quality verification [ 17 , 18 , 19 ]. The AQbD concept is commonly applied to pharmaceutical development and was recently introduced in the analysis of foods, reinforcing its contribution to the methods harmonization [ 20 , 21 , 22 ].…”