Chemical Analysis of Veterinary Drug Residues in Salmon Tissue

The Irish finfish-farming section has increased from 20 tonnes in 1980 to 15,440 in 1997. The sales value of the 15,440 tonnes was £37.5 M where exports were worth approximately £30 M of this. This increasing intensity of fish farming has inevitably been paralleled by increases in disease, which has force the mariculturist to increase the use of chemicals. A major concern with the use of chemicals in mariculture is residues, which may remain in the fish tissue after harvesting and resulting in exposure to the consumer. Under Council Directive 96/23/EC Member States are required to monitor on a routine basis, veterinary drug residues in animals and animal products. The aim of this monitoring plan is to ascertain that residues, where present are below the maximum residue limit (MRL), and that no residues are present for analytes which do not have an established MRL. In consistence with this Directive, HPLC methods were optimised and validated according to the criteria set out in Commission Decision 93/256/EEC for the qualitative and quantitative analysis in farmed salmon tissue, of oxytetracycline (OTC), oxolinic acid (OA), sulphadiazine (SD), sulphamethoxazole (SMX) and trimethoprim (TMP). All methods were found to be linear from 50-150% of the respective MRLS, while recoveries were within the required 70-110% range for OTC, OA, SD and SMX. The precision obtained at 100ugky-1 was 2.1% RSD (n=5), 1.5% RSD (n=8), 9.7% RSD (=6) AND 8.4% RSD (N=6) for OA, OTC, SD and SMX respectively. The limit of detection (LOD) based on S/N=3, was found to be 10.0ugkg-1, 20.1ugkg-1, 1.0ugkg and 2.6ugkg-1 respectively, for OA, OTC,SD and SMX. Based on S/N=5, the limit of quantification (LOQ) in tissue samples was 11.3ugkg-1, 37.6ugkg-1, 1.6ugkg-1 and 8.2ugkg-1 for OA, OTC, SD and SMX respectively. In addition to the above chemical ivermectin and cypermethrin were examined using size exclusion chromatography (SEC) as a possible screening and clean-up technique. A SEC method capable of screen 16 samples in one overnight run, for residues of SD, SMX and OA in tissue, at 50ugkg-1 was developed. Additionally SEC was developed as a cleanup technique to increase sample throughput for ivermectin analysis

A LCMS Metabolomic Workflow to Investigate Metabolic Patterns in Human Intestinal Cells Exposed to Hydrolyzed Crab Waste Materials

We have developed a LCMS metabolomic workflow to investigate metabolic patterns from human intestinal cells treated with simulated gastrointestinal-digested hydrolyzed crab waste materials. This workflow facilitates smart and reproducible comparisons of cell cultures exposed to different treatments. In this case the variable was the hydrolysis methods, also accounting for the GI digestion giving an output of direct correlation between cellular metabolic patterns caused by the treatments. In addition, we used the output from this workflow to select treatments for further evaluation of the Caco-2 cell response in terms of tentative anti-inflammatory activity in the hopes to find value in the crab waste materials to be used for food products. As hypothesized, the treatment identified to change the cellular metabolomic pattern most readily, was also found to cause the greatest effect in the cells, although the response was pro-inflammatory rather than anti-inflammatory, it proves that changes in cellular metabolic patterns are useful predictors of bioactivity. We conclude that the developed workflow allows for cost effective, rapid sample preparation as well as accurate and repeatable LCMS analysis and introduces a data pipeline specifically for probe the novel metabolite patterns created as a means to assess the performing treatments

Humic Acid and Trihalomethane Breakdown with Potential By-Product Formations for Atmospheric Air Plasma Water treatment

Over the past century chlorine has been widely used as an oxidant in water and wastewater treatment. Chlorine’s efficacy is demonstrated for microbial inactivation of a wide variety of pathogens along with oxidation of various chemical contaminants. However, the potential formation of disinfection by-products (DBPs), such as trihalomethane, is a concern [1]. DBPs, including trihalomethanes, can be formed as a consequence of the reaction of chlorine with natural organic matter (NOM) present in both surface and ground water [2]. NOM comprises of two fractions; humic substances (HS), which are composed of humic acids, fulvic acids, and non-humic substances (non-HS), which include carbohydrates, lipids, and amino acids [3]. Furthermore, humic acids constitute a major fraction of NOM, of which the soluble portion (aromatic compounds) of humic substances may react with chlorine to form trihalomethanes [4]. It has been reported that these THMs are carcinogens [5]. Epidemiologic studies in humans suggest a weak association with bladder, rectal and colon cancer [6,7] along with reproductive and developmental effects [8,9]. Due to these health concerns, many jurisdictions specify maximum allowable concentrations. The United States Environ- mental Protection Agency [10] specifies maximum levels for trihalomethanes (THMs) and haloacetic acids (HAAs) of 80 and 60 mg/L, respectively [11]. European Union regulations limit THMs to 100 mg/L. However, many national reports find frequent occurrence of THM exceedance [12]. It is important to limit THMs and THMs causing substances (humic acids) in water. Several approaches such as nanofiltration, ultrafiltration, reverse osmosis coagulation [13], activated carbon adsorption [14], Fenton treatment [15], nano-TiO2 photocatalysis [16], membrane filtration [17], biological treatment [18], and ozonation [19] have been employed to remove humic substances and THM’s. Biological processes, including the use of bio-filters may lead to the accumulation of suspended solids and release of bacteria [20]. Separation technologies such as biofilms and membrane filtration may be limited due to fouling [21]. Ozone’s efficacy for humic substance breakdown in water has been demonstrated, however the process may result in the formation of brominated by-products [22]. In addition, the use of such advanced oxidation processes (AOP) which are capable of oxidizing some of the NOM present in raw water sources require an additional step for mineralization increasing the operational cost. Therefore, there is a need to develop novel approaches to remove humic substances and THMs in energy efficient manner

Improving Extraction Processes of Crustacean Chitin Using Solid State Analytical Techniques

Solid state analytical techniques are becoming more widely used for the analysis of a range of organic products which demonstrate very poor solubility in both common organic and polar solvents and as such cannot be accurately characterised using solution based techniques. Primarily used as a secondary technique for qualitative analysis of insoluble intermediates and products in organic synthesis, 13C CP-MAS NMR can be utilised in tandem with a targeted extraction and clean up procedure for accurate quantitative analysis of insoluble bio-molecules of interest. Here solid state 13C CP-MAS NMR is utilised as the primary analytical technique in the characterisation of crustacean sourced chitin whereby Cancer pagurus crab shell chitin and Pandalus borealis shrimp shell chitin are shown to have a degree of acetylation greater than 90%. FTIR spectroscopy, Raman spectroscopy and DSC provide secondary structural, molecular and thermal analysis of the raw materials and extracted chitin

Development and Validation of a Rapid Multi-class Method for the Confirmation of Fourteen Prohibited Medicinal Additives in Pig and Poultry Compound Feed by Liquid Chromatography Tandem Mass Spectrometry

A confirmatory method has been developed to allow for the analysis of fourteen prohibited medicinal additives in pig and poultry compound feed. These compounds are prohibited for use as feed additives although some are still authorised for use in medicated feed. Feed samples are extracted by acetonitrile with addition of sodium sulphate. The extracts undergo a hexane wash to aid with sample purification. The extracts are then evaporated to dryness and reconstituted in initial mobile phase. The samples undergo an ultracentrifugation step prior to injection onto the LC-MS/MS system and are analysed in a run time of 26 minutes. The LC-MS/MS system is run in MRM mode with both positive and negative electrospray ionisation. The method was validated over three days and is capable of quantitatively analysing for metronidazole, dimetridazole, ronidazole, ipronidazole, chloramphenicol, sulfadiazine, sulfamethazine, dinitolimide, ethopabate, carbadox and clopidol. The method is also capable of qualitatively analysing for tylosin, virginiamycin and avilamycin. A level of 100 μg kg-1 was used for validation purposes and the method is capable of analysing to this level for all the compounds. Validation criteria of trueness, precision, repeatability and reproducibility along with measurement uncertainty are calculated for all analytes

An Assessment of Contamination Fingerprinting Techniques for Determining the Impact of Domestic Wastewater Treatment Systems on Private Well Supplies

Private wells in Ireland and elsewhere have been shown to be prone to microbial contamination with the main suspected sources being practices associated with agriculture and domestic wastewater treatment systems (DWWTS). While the microbial quality of private well water is commonly assessed using faecal indicator bacteria, such as Escherichia coli, such organisms are not usually source-specific, and hence cannot definitively conclude the exact origin of the contamination. This research assessed a range of different chemical contamination fingerprinting techniques (ionic ratios, artificial sweeteners, caffeine, fluorescent whitening compounds, faecal sterol profiles and pharmaceuticals) as to their use to apportion contamination of private wells between human wastewater and animal husbandry wastes in rural areas of Ireland. A one-off sampling and analysis campaign of 212 private wells found that 15% were contaminated with E. coli. More extensive monitoring of 24 selected wells found 58% to be contaminated with E. coli on at least one occasion over a 14-month period. The application of fingerprinting techniques to these monitored wells found that the use of chloride/bromide and potassium/sodium ratios is a useful low-cost fingerprinting technique capable of identifying impacts from human wastewater and organic agricultural contamination, respectively. The artificial sweetener acesulfame was detected on several occasions in a number of monitored wells, indicating its conservative nature and potential use as a fingerprinting technique for human wastewater. However, neither fluorescent whitening compounds nor caffeine were detected in any wells, and faecal sterol profiles proved inconclusive, suggesting limited suitability for the conditions investigated

Using the Community of Practice model to shape approaches to Education for Sustainable Development across disciplines in a Technological University context: A Roundtable Podcast

This roundtable discussion podcast comprises eight colleagues engaged in reflective discussion of their shared experiences of being members of SDG Literacy.ie, a Community of Practice (CoP) first established in TU Dublin in 2020. This CoP focuses on and promotes the enhancement of Sustainability Literacy among student cohorts as one measure to be employed in strengthening Education for Sustainable Development (ESD) in line with the broader strategic aims of the university. Harvey et al. (2021) in a case-based paper which includes examination of the CoP discussed here conclude that teaching and learning innovation took place as a consequence of the resource-sharing, idea-generation and overall peer support that CoP members experience. The voices you will hear in this podcast discussion represent the inter-disciplinary SDG Literacy academic community who all share an interest in the sustainability domain and are acutely aware of SDG4.7 which focuses on ensuring all learners acquire the knowledge and skills for sustainable development by 2030. Discussion themes include (i) our shared understanding of ESD, (ii) how membership of SDGLiteracy.ie shaped our Teaching, Learning and Assessment (TLA) approaches in relation to ESD, Sustainability Literacy and Authentic Assessment, (iii) how membership of SDGLiteracy.ie shaped our broader personal and professional development (research, collaboration, output etc.) and (iv) our future plans in relation to ESD and the CoP model. The podcast transcript has been annotated through footnotes to direct the listener/reader to further reading on the various topics that emerge in the discussion

Valorisation of crustacean and bivalve processing side streams for industrial fast time-to-market products: A review from the European Union regulation perspective

A massive amount of crustaceans and bivalves are consumed each year, leading to millions of tons of processing side streams from the seafood industry. Considering the current trend of (bio)circular and zero-waste food production, crustacean and bivalve processing side streams (CBPS) seem a promising and emerging resource for producing high-value-added products. This paper highlights the general composition of CBPS with high commercial values, namely, protein, lipids, carotenoids, minerals and chitins. The extraction strategies of these fractions, including conventional chemical and environmentally friendly methods, are also discussed. This review presents and summarises CBPS as raw materials for developing fast time-to-market products complying with specific EU regulations, including animal feeds, bio-pesticide/stimulants, and cosmetic ingredients. This paper also provides insights into challenges of applying CBPS as raw materials to generate products for human consumption

5 Ways For Us To Value Water In Our Daily Lives

Not everyone around the world can turn on a tap in their house to drink clean, fresh water, let alone flush a toilet with the push of a button. The Covid-19 pandemic demonstrated the critical importance of adequate access to safe water and sanitation for preventing and containing diseases. According to the World Health Organisation, handwashing is one of the most effective actions you can take to reduce the spread of pathogens and prevent infections