Detection of s-Triazine pesticides in natural waters by modified large-volume direct injection HPLC

There is a need for simple and inexpensive methods to quantify potentially harmful persistent pesticides often found in our water-ways and water distribution systems. This paper presents a simple, relatively inexpensive method for the detection of a group of commonly used pesticides (atrazine, simazine and hexazinone) in natural waters using large-volume direct injection high performance liquid chromatography (HPLC) utilizing a monolithic column and a single wavelength ultraviolet–visible light (UV–vis) detector. The best results for this system were obtained with a mobile phase made up of acetonitrile and water in a 30:70 ratio, a flow rate of 2.0 mL min−1, and a detector wavelength of 230 nm. Using this method, we achieved retention times of less than three minutes, and detection limits of 5.7 μg L−1 for atrazine, 4.7 μg L−1 for simazine and 4.0 μg L−1 for hexazinone. The performance of this method was validated with an inter-laboratory trial against a National Association of Testing Authorities (NATA) accredited liquid chromatography–mass spectrometry/mass spectrometry (LC–MS/MS) method commonly used in commercial laboratories

<i>InSpectra</i> - A platform for identifying emerging chemical threats

Non-target analysis (NTA) employing high-resolution mass spectrometry (HRMS) coupled with liquid chromatography is increasingly being used to identify chemicals of biological relevance. HRMS datasets are large and complex making the identification of potentially relevant chemicals extremely challenging. As they are recorded in vendor-specific formats, interpreting them is often reliant on vendor-specific software that may not accommodate advancements in data processing. Here we present InSpectra, a vendor independent automated platform for the systematic detection of newly identified emerging chemical threats. InSpectra is web-based, open-source/access and modular providing highly flexible and extensible NTA and suspect screening workflows. As a cloud-based platform, InSpectra exploits parallel computing and big data archiving capabilities with a focus for sharing and community curation of HRMS data. InSpectra offers a reproducible and transparent approach for the identification, tracking and prioritisation of emerging chemical threats

Current-Use Pesticides in New Zealand Streams: Comparing Results From Grab Samples and Three Types of Passive Samplers

New Zealand uses more than a ton of pesticides each year; many of these are mobile, relatively persistent, and can make their way into waterways. While considerable effort goes into monitoring nutrients in agricultural streams and programs exist to monitor pesticides in groundwater, very little is known about pesticide detection frequencies, concentrations, or their potential impacts in New Zealand streams. We used the ‘Polar Organic Chemical Integrative Sampler’ (POCIS) approach and grab water sampling to survey pesticide concentrations in 36 agricultural streams in Waikato, Canterbury, Otago and Southland during a period of stable stream flows in Austral summer 2017/18. We employed a new approach for calculating site-specific POCIS sampling rates. We also tested two novel passive samplers designed to reduce the effects of hydrodynamic conditions on sampling rates: the ‘Organic-Diffusive Gradients in Thin Films’ (o-DGT) aquatic passive sampler and microporous polyethylene tubes (MPTs) filled with Strata-X sorbent. Multiple pesticides were found at most sites; two or more were detected at 78% of sites, three or more at 69% of sites, and four or more at 39% of sites. Chlorpyrifos concentrations were the highest, with a maximum concentration of 180 ng/L. Concentrations of the other pesticides were generally below 20 ng/L. Mean concentrations of individual pesticides were not correlated with in-stream nutrient concentrations. The majority of pesticides were detected most frequently in POCIS, presumably due to its higher sampling rate and the relatively low concentrations of these pesticides. In contrast, chlorpyrifos was most frequently detected in grab samples. Chlorpyrifos concentrations at two sites were above the 21-day chronic ‘No Observable Effect Concentration’ (NOEC) values for fish and another two sites had concentrations greater than 50% of the NOEC. Otherwise, concentrations were well-below NOEC values, but close to the New Zealand Environmental Exposure Limits in several cases

Quantitative Analysis of Selected Plastics in High-Commercial-Value Australian Seafood by Pyrolysis Gas Chromatography Mass Spectrometry

This is the final version. Available on open access from the American Chemical Society via the DOI in this recordMicroplastic contamination of the marine environment is widespread, but the extent to which the marine food web is contaminated is not yet known. The aims of this study were to go beyond visual identification techniques and develop and apply a simple seafood sample cleanup, extraction, and quantitative analysis method using pyrolysis gas chromatography mass spectrometry to improve the detection of plastic contamination. This method allows the identification and quantification of polystyrene, polyethylene, polyvinyl chloride, polypropylene, and poly(methyl methacrylate) in the edible portion of five different seafood organisms: oysters, prawns, squid, crabs, and sardines. Polyvinyl chloride was detected in all samples and polyethylene at the highest total concentration of between 0.04 and 2.4 mg g-1 of tissue. Sardines contained the highest total plastic mass concentration (0.3 mg g-1 tissue) and squid the lowest (0.04 mg g-1 tissue). Our findings show that the total concentration of plastics is highly variable among species and that microplastic concentration differs between organisms of the same species. The sources of microplastic exposure, such as packaging and handling with consequent transference and adherence to the tissues, are discussed. This method is a major development in the standardization of plastic quantification techniques used in seafood.University of QueenslandUniversity of ExeterNatural Environment Research Council (NERC)Queensland Department of Healt

Aquatic Global Passive Sampling (AQUA-GAPS) Revisited – First Steps towards a Network of Networks for Organic Contaminants in the Aquatic Environment

Organic contaminants, in particular persistent organic pollutants (POPs), adversely affect water quality and aquatic food webs across the globe. As of now, there is no globally consistent information available on concentrations of dissolved POPs in water bodies. The advance of passive sampling techniques has made it possible to establish a global monitoring program for these compounds in the waters of the world, which we call the Aquatic Global Passive Sampling (AQUA-GAPS) network. A recent expert meeting discussed the background, motivations, and strategic approaches of AQUA-GAPS, and its implementation as a network of networks for monitoring organic contaminants (e.g., POPs and others contaminants of concern). Initially, AQUA-GAPS will demonstrate its operating principle via two proof-of-concept studies focused on the detection of legacy and emerging POPs in freshwater and coastal marine sites using both polyethylene and silicone passive samplers. AQUA-GAPS is set-up as a decentralized network, which is open to other participants from around the world to participate in deployments and to initiate new studies. In particular, participants are sought to initiate deployments and studies investigating the presence of legacy and emerging POPs in Africa, Central and South America

Determination of emerging pollutants using passive microporous polyethylene samplers and liquid chromatography tandem mass spectrometry in L'Albufera Natural Park (Valencia, Spain)

Trabajo presentado en el 18th Annual Workshop on Emerging High Resolution Mass Spectrometry (HRMS) and LC-MS/MS Applications on Environmental and Food Analysis, celebrado en Barcelona (España) del 10 al 11 de octubre de 2022.Monitoring the presence of pollutants in environmental waters has revealed a large number of emerging contaminants of concern. In surface waters, the presence of episodes such as accidental spills, surface runoff, losses or deliberate industrial release can be difficult to capture and adequately quantify if water samples are taken at a single point in time that may or may not be representative of the pollutant concentration at the time of sampling. In order to estimate the concentrations of pollutants across a more representative and larger time scale and to be able to accurately assess the environmental load, passive samplers can provide an alternative sampling strategy. In the present study, passive samplers were deployed, each containing triplicate cylindrical microporous polyethylene tubes with absorbent phases to retain emerging polar pollutants of moderate polarity in 12 sampling points of the L´ Albufera Natural Park (Valencia, Spain). The sampling points differ in their hydrological characteristics and / or source of contamination. Passive samplers were concurrently deployed for durations of both 14 and 28 days. Once in the laboratory, the sorbent from the samplers was removed to quantify a wide variety of emerging contaminants, including pharmaceuticals, pesticides, poly and perfluoroalkyl substances (PFASs) and phosphorous flame retardants (PFRs) using high performance mass spectrometry (HPLC-MS). In addition, contaminant concentrations were compared across the two different deployment periods (i.e., 14 and 28 days). The results obtained highlight some differences observed for certain compounds at 14 and 28 days, as well as the high concentrations of certain compounds, including 2,4-dimethylphenyl formamide, tebuconazole, prochloraz, etofenprox and azoxystrobin and PFOS. Passive samplers proved to be a good option for water sampling by achieving in situ accumulation of analytes within a receiving phase during a medium-term exposure in the sampled waters.This work has been supported by Grant RTI2018-097158-B-C31 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” and the grant of the Generalitat Valenciana Prometeo Programme CIPROM/2021/032. Y. Soriano also thanks MCIN/AEI/ 10.13039/501100011033 and ERDF for their Predoc contract (PRE2019-089042)