Jessica Briffa

Bio: Jessica Briffa is an academic researcher from University of Malta. The author has contributed to research in topics: High-performance liquid chromatography & Thin-layer chromatography. The author has an hindex of 2, co-authored 3 publications receiving 193 citations.

Analysis of other phenolics (capsaicin, gingerol, and alkylresorcinols)

Abstract: Phenolic compounds exhibit a wide variety of biological effects because of their antioxidant properties. Phenolic compounds have widespread occurrence in nature and are consumed by humans through diet consisting of fruits and vegetables. The gradually increasing interest in phenolic acids profile is directly proportional to their antioxidant activity and potential benefits for health as they protect the human body from free radicals and their formation is associated with normal natural metabolism of aerobic cells. Protective phenylpropanoid metabolism pathways in plants have been well-documented which results in the biosynthesis of phenolic compounds. The antiradical activity of phenolics and flavonoids is chiefly based on the reduction-oxidation properties of the hydroxyl group they contain as well as the structural relationships between different parts of the chemical structures of these compounds. Epidemiological data have exhibited various benefits of antioxidant compounds in the prevention of a wide range of disease states like cancer, cardiovascular disease, and neurodegenerative disorders. From the past few years, identification and development of phenolic compounds from various plants has become a major area of health and medical-related research studies. This chapter provides an updated and comprehensive overview on capsaicin, gingerol, and alkylresorcinols extraction, purification, and quantification as well as their antioxidant properties. The extraction of capsaicin, gingerol, and alkylresorcinols from source material is the first step involved in their analysis. They are extracted by solvent extraction, which is a conventional method, and modern methods such as subcritical fluid extraction (SFE) and ultrasonic-assisted extraction. The content of capsaicin, gingerol, and alkylresorcinols in the extract is determined using chemical, chromatographic, and spectrometric analysis. Thin layer chromatography (TLC), gas chromatography coupled with mass spectrometry (GC-MS), high performance liquid chromatography (HPLC), and liquid chromatography tandem mass spectrometry (LC-MS/MS) are employed for the identification and quantification of the individual compounds present.

Analysis of pentaterpenoids

Abstract: Triterpenes are the most representative group of phytochemicals, with over 30,000 compounds being known to exist. These compounds are composed of six C5 isoprene units and are biosynthesized via the cyclization of squalene. They have been found to possess several pharmacological properties such as anticancer, anti-HIV, and antiinflammatory actions. Interestingly, plants containing substantial levels of pentacyclic triterpenes have been used in folk medicine in many parts of the world since ancient times. The average daily consumption of pentacyclic triterpenes has been estimated to be around 250 mg which is higher than that in the Mediterranean diet. Most of the pentacyclic triterpenes found in fruits such as oleanolic acid and ursolic acid are distributed within the skin and cuticular wax. Therefore, there is substantial loss of these compounds if the fruits have their skin removed during processing. Extraction of these compounds can be achieved through the use of different techniques, including conventional methods such as Soxhlet and shaking extraction and newer methods such as microwave-assisted extraction and supercritical fluid extraction. Future trends of analysis are also being reviewed such as high-speed countercurrent chromatography. New developments have been made to this analysis such as cross-axis countercurrent chromatography, foam countercurrent chromatography, dual countercurrent chromatography, and pH-zone-refining countercurrent chromatography.

Various Natural and Anthropogenic Factors Responsible for Water Quality Degradation: A Review

Abstract: Recognition of sustainability issues around water resource consumption is gaining traction under global warming and land utilization complexities. These concerns increase the challenge of gaining an appropriate comprehension of the anthropogenic activities and natural processes, as well as how they influence the quality of surface water and groundwater systems. The characteristics of water resources cause difficulties in the comprehensive assessment regarding the source types, pathways, and pollutants behaviors. As the behavior and prediction of widely known contaminants in the water resources remain challenging, some new issues have developed regarding heavy metal pollutants. The main aim of this review is to focus on certain essential pollutants’ discharge from anthropogenic activities categorized based on land-use sectors such as industrial applications (solid/liquid wastes, chemical compounds, mining activities, spills, and leaks), urban development (municipal wastes, land use practices, and others), and agricultural practices (pesticides and fertilizers). Further, important pollutants released from natural processes classified based on climate change, natural disasters, geological factors, soil/matrix, and hyporheic exchange in the aquatic environment, are also discussed. Moreover, this study addresses the major inorganic substances (nitrogen, fluoride, and heavy metals concentrations). This study also emphasizes the necessity of transdisciplinary research and cross-border communication to achieve sustainable water quality using sound science, adaptable legislation, and management systems.

Recent advances in activated carbon modification techniques for enhanced heavy metal adsorption

Abstract: The contamination of water with heavy metals is a global issue. Its water solubility and non-degradability nature convert it into a potential threat to human health as well as flora and fauna. Several methods have been applied for heavy metal removal from water using a different mechanism, which differs in specification and removal efficacy. Activated carbon has recently attracted the attention of wastewater treatment industries because of its significantly high adsorption capacity against heavy metals. The large surface area, suitable surface functional groups, and appropriate pore diameter make activated carbon a potential adsorbent. Significant advances have been recently reported to modify the activated carbon using physical, chemical, organic, and inorganic loading techniques to improve the adsorption performance of activated carbon. This review presents the recent advances in activated carbon preparation and modification for heavy metal removal from water. Different fabrication techniques and the mechanisms of heavy metal adsorption are also discussed in detail.

Review of soil heavy metal pollution in China: Spatial distribution, primary sources, and remediation alternatives

Abstract: With the development of economy, soil heavy metal pollution becomes more severe, which causes soil resource degradation and ecosystem deterioration. In this study, we present the locations with excessive contamination and analyze heavy metal polluted provinces, as well as the status and primary factors of heavy metal pollution in Guangxi, Fujian, Liaoning and Yunnan provinces, which contain the hotspots at the city level. Results indicate that the heavy metal concentration increased from north to south in China. Soil heavy metal pollution is typical in Northeast China; Also, it is widespread in southern China, with heavy metals exceeding the standard levels in Central, Southwest and South China. Heat map reveals that mineral exploitation and industrial production are the primary causes in the most severely polluted provinces, while sewage irrigation or irrational application of fertilizer is the cause in agricultural areas. Urban development in densely populated provinces has become the third main factor. In addition, transportation and household refuse are potential driving factors. Network analysis suggests combined remediation methods are widely applied to improve remediation efficiency. Among them, physical-chemical technology, chemical-biological technology and physical-biological technology occupy 27.1%, 18.9% and 10.7% in the above four provinces. In particular, combining phytoremediation and microbial remediation techniques is the main research direction in future because of its environmental friendly. In brief, our study provides accurate spatial information, primary sources and appropriate remediation alternatives for soil heavy metal pollution in China, benefiting soil resource protection and land utilization.