BLENDED DELIVERY OF UNDERGRADUATE CHEMISTRY LABORATORIES DUE TO COVID-19

COVID-19 has had a profound impact on tertiary education, most notably the rapid transition from face-to-face classes to online methods of teaching. This has posed significant challenges for laboratory classes, where students normally acquire technical, data analysis and communication skills through direct hands-on experience. Achieving these learning outcomes amid a global pandemic requires fundamental re-design of laboratory activities and their assessment. This presentation will provide a case study of how a second-year analytical chemistry unit was adapted to provide a blended learning experience. Half of the laboratories were transitioned into take-home activities using video recordings, sample data and additional online resources in place of face-to-face sessions. A revised report format was introduced, enabling students to demonstrate their knowledge of the underpinning chemistry and laboratory safety without physical attendance. The remaining laboratories were held face-to-face and assessed through a competency criterion system, maximising the value of students’ on-campus experience. An analysis will be provided of lessons learned from the adaptation process and how this will be used for continuous unit improvement

Investigation into the performance of physical developer formulations for visualizing latent fingerprints on paper

Latent fingerprints deposited on commercial photocopy paper were treated using various preparations of silver-based physical developer and the results from each were compared to those obtained with the standard formulation used by the Australian Federal Police. Five redox stock solutions were prepared with altered orders of reagent addition, and a further solution prepared with exchanged iron concentrations, to test the robustness of the method. Three redox solutions were prepared with specific reagents omitted to determine the significance of the role played by each in development. One redox solution was prepared using Tween 20 as the non-ionic surfactant to assess its suitability as a replacement for Synperonic N. An acid prewash was also prepared using malic acid as an alternative to maleic acid. Results showed the method to be robust to alterations in reagent addition, but not to significant concentration changes. The presence of all components was found to be desirable for distinguishable development of fingerprint detail. It was additionally found that Tween 20 gave at least equal performance to Synperonic N on recently deposited fingerprints. Finally, the use of malic acid gave equivalent fingerprint development but higher background in comparison to maleic acid

Forensic science in Seychelles: An example of a micro-jurisdiction forensic delivery system

Forensic science has become an indispensable tool for even the smallest of jurisdictions. However, micro-jurisdictions often face significant challenges with respect to resource availability, administration and local governance. This paper examines the forensic service provision in Seychelles as an example of a micro-jurisdiction forensic delivery system. The impact of limited resources and remote access to consumables or services have prompted the prospective shift to localise commonly utilised forensic services. The need to balance quality and cost for a sustainable forensic service is examined in relation to jurisdictions with more advanced forensic service delivery. Reforms of the legal framework, administration, and governance structures are some of the key underpinnings for an effective forensic delivery system built on a culture of transparent science that promotes justice and creates public confidence in the judicial system

Applications of chemometrics to the analysis and interpretation of forensic physical evidence

Forensic investigations often rely upon items of physical evidence. However, current interpretation protocols for such evidence are subjective, leading to potential bias in forensic examinations. Chemometric techniques may be used to develop more objective methods for assessing evidential significance, as well as establishing statistically validated evidential procedures. This dissertation describes the application of chemometrics to various aspects of physical evidence examination, with a specific focus on textile fibres, pen inks and explosive residues

SCAFFOLDING FOR IMPACT: ACTIVE LEARNING IN FORENSIC EDUCATION

Forensic science programs attract students from a range of scientific disciplines including chemistry, biology, psychology and engineering. At the tertiary level, these students are expected to demonstrate a mastery of forensic principles with the ability to apply them in practice. However, there has been little investigation of effective pedagogical approaches to achieve these outcomes in forensic education. Active learning has long been recognised within other scientific disciplines as an effective means of promoting mastery, motivation, and higher-order thinking skills. Despite this, active learning has yet to be systematically evaluated within a forensic context. This project applied a mixed methods approach to evaluate how active learning strategies influence students’ academic achievement and attitudes towards learning in an introductory forensic science unit. The outcomes and implications of these results will be discussed in relation to establishing scholarly practices for forensic education and training

A study into the ageing and dating of blue ball tip inks on paper using in situ visible spectroscopy with chemometrics

This paper presents a study into the potential of visible spectroscopy with chemometrics as an approach to dating blue ball tip inks on paper documents. Analysis of six inks left under various conditions found that the majority of those kept in the dark could still be matched to the source pen after 32 months of ageing. Conversely, the majority of those exposed to light exhibited rapid spectral changes that continued throughout the 32 month period. Partial least squares regression (PLSR) was used to generate dating models for inks aged with exposure to light. Evaluation using an external test set found absolute dating to be challenging for these ink deposits within the first 2-6 months of ageing. However, predictive accuracy was found to improve for long-term ageing, with two-year old samples yielding age estimates with a maximum error of 6 months. This rapid, non-destructive methodology could assist document examiners in the relative ageing or approximate age determination of questioned documents, as well as the identification of document alterations

Preliminary studies into the effect of environmental degradation on the characterisation of automotive clear coats by attenuated total reflectance infrared spectroscopy

This paper presents a study into the impact of environmental weathering on the chemometric classification of automotive clear coats. These studies were conducted using attenuated total reflectance infrared spectroscopy, in conjunction with a chemometric model capable of predicting the country of vehicle manufacture for a sample based upon its infrared spectrum. Testing of three samples exposed to environmental conditions found the model to be robust to weathering over at least an eight-month period. However, analysis of 12 samples of unknown prior history found that extreme degradation over at least a 10-year period, or the presence of a post-manufacture (respray) coating, could result in misclassification when relying solely on analysis of the clear coat. It is therefore important that cross-sections comprising the full layer sequence of the paint system are obtained wherever possible, as analysis of the underlying layers may give more comprehensive characterisation

Chemometrics in forensic science: Approaches and applications

Forensic investigations are often reliant on physical evidence to reconstruct events surrounding a crime. However, there remains a need for more objective approaches to evidential interpretation, along with rigorously validated procedures for handling, storage and analysis. Chemometrics has been recognised as a powerful tool within forensic science for interpretation and optimisation of analytical procedures. However, careful consideration must be given to factors such as sampling, validation and underpinning study design. This tutorial review aims to provide an accessible overview of chemometric methods within the context of forensic science. The review begins with an overview of selected chemometric techniques, followed by a broad review of studies demonstrating the utility of chemometrics across various forensic disciplines. The tutorial review ends with the discussion of the challenges and emerging trends in this rapidly growing field

“Wax On, Wax Off”: In Vivo Imaging of Plant Physiology and Disease with Fourier Transform Infrared Reflectance Microspectroscopy

Analysis of the epicuticular wax layer on the surface of plant leaves can provide a unique window into plant physiology and responses to environmental stimuli. Well-established analytical methodologies can quantify epicuticular wax composition, yet few methods are capable of imaging wax distribution in situ or in vivo. Here, the first report of Fourier transform infrared (FTIR) reflectance spectroscopic imaging as a non-destructive, in situ, method to investigate variation in epicuticular wax distribution at 25 µm spatial resolution is presented. The authors demonstrate in vivo imaging of alterations in epicuticular waxes during leaf development and in situ imaging during plant disease or exposure to environmental stressors. It is envisaged that this new analytical capability will enable in vivo studies of plants to provide insights into how the physiology of plants and crops respond to environmental stresses such as disease, soil contamination, drought, soil acidity, and climate change

Classification of polyethylene cling films by attenuated total reflectance-Fourier transform infrared spectroscopy and chemometrics

Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) was utilised to analyse nine differently branded cling films. Principal component analysis (PCA) was used to assess the intra-sample variability, i.e. the variation within individual cling film rolls; as well as the inter-sample variability, which explores the variability between different rolls of cling film. Linear discriminant analysis (LDA) was then employed to develop a predictive classification model which gave 100% correct differentiation between three brand groupings of cling film, and accurately classified all of the validation samples obtained from different rolls from the same manufacturers