High Sample Throughput Research Articles

A miniaturized flow batch chemical vapor generation system for Hg determination in fish by ICP-MS

A new flow batch (FB) system for chemical vapor generation (CVG) is proposed for mercury (Hg) determination in fish. An inductively coupled plasma mass spectrometer was used as a detector. Low-cost peristaltic mini pumps were used to propel the solutions and different configurations of FB systems (reactor/gas/liquid separator) were studied. The proposed configuration of the FB-CVG system allows good sensitivity, low limit of detection (LOD) and low consumption of reagents and sample solutions. In summary, only 1 mL of reductant, 1 mL of acid and 0.16 mL of sample are needed. The proposed method has good linearity, precision (better than 5 %), LOD of 0.008 μg g−1 and LOQ of 0.012 μg g−1, and high sample throughput, allowing 90 measurements/h. The accuracy of the method was evaluated through the analysis of a certified reference material (DOLT-4 Dogfish Liver), whose result is in good agreement with certified value (t-test with 95 % confidence level) and the quantification limit meets current legislations, of 1.0 μg g−1 (Brazil) and 0.3 μg g−1 (EU). In addition, analyte recovery test was done, where Hg recovery was better than 95 %, demonstrating the good analytical performance of the method. To demonstrate the applicability of the method, five samples of fish tissue (muscle) were analyzed. The proposed FB-CVG system, in addition to being low cost, is robust and requires only the volume of reagents necessary for Hg vapor generation, producing a very low amount of waste. It can be concluded that the proposed system can be used for routine analysis for Hg determination in fish tissue. It is worth noting that with the appropriate adjustments, the system can be coupled to different Hg detectors.

Development and Assessment of Multiple Illumination Color Fourier Ptychographic Microscopy for High Throughput Sample Digitization.

In this study, we proposed a multiplexed color illumination strategy to improve the data acquisition efficiency of Fourier ptychography microscopy (FPM). Instead of sequentially lighting up one single channel LED, our method turns on multiple white light LEDs for each image acquisition via a color camera. Thus, each raw image contains multiplexed spectral information. An FPM prototype was developed, which was equipped with a 4×/0.13 NA objective lens to achieve a spatial resolution equivalent to that of a 20×/0.4 NA objective lens. Both two- and four-LED illumination patterns were designed and applied during the experiments. A USAF 1951 resolution target was first imaged under these illumination conditions, based on which MTF curves were generated to assess the corresponding imaging performance. Next, H&E tissue samples and analyzable metaphase chromosome cells were used to evaluate the clinical utility of our strategy. The results show that the single and multiplexed (two- or four-LED) illumination results achieved comparable imaging performance on all the three channels of the MTF curves. Meanwhile, the reconstructed tissue or cell images successfully retain the definition of cell nuclei and cytoplasm and can better preserve the cell edges as compared to the results from the conventional microscopes. This study initially validates the feasibility of multiplexed color illumination for the future development of high-throughput FPM scanning systems.

Incorporating Prior Knowledge in the Seeds of Adaptive Sampling Molecular Dynamics Simulations of Ligand Transport in Enzymes with Buried Active Sites.

Because most proteins have buried active sites, protein tunnels or channels play a crucial role in the transport of small molecules into buried cavities for enzymatic catalysis. Tunnels can critically modulate the biological process of protein-ligand recognition. Various molecular dynamics methods have been developed for exploring and exploiting the protein-ligand conformational space to extract high-resolution details of the binding processes, a recent example being energetically unbiased high-throughput adaptive sampling simulations. The current study systematically contrasted the role of integrating prior knowledge while generating useful initial protein-ligand configurations, called seeds, for these simulations. Using a nontrivial system of a haloalkane dehalogenase mutant with multiple transport tunnels leading to a deeply buried active site, simulations were employed to derive kinetic models describing the process of association and dissociation of the substrate molecule. The most knowledge-based seed generation enabled high-throughput simulations that could more consistently capture the entire transport process, explore the complex network of transport tunnels, and predict equilibrium dissociation constants, koff/kon, on the same order of magnitude as experimental measurements. Overall, the infusion of more knowledge into the initial seeds of adaptive sampling simulations could render analyses of transport mechanisms in enzymes more consistent even for very complex biomolecular systems, thereby promoting drug development efforts and the rational design of enzymes with buried active sites.

Differences in bile acid profiles between cholestatic diseases – Development of a high throughput assay for dried bloodspots

BackgroundCholestasis causes accumulation of bile acids (BAs) and changes the circulating bile acid profile. Quantification of circulating BAs in dried bloodspots (DBS) may demonstrate obstruction of bile flow and altered bile acid metabolism in the liver. High sample throughput enables rapid screening of cholestatic diseases. Materials and methodsUltra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was used for optimizing separation and detection of the primary unconjugated BAs cholic acid (CA) and chenodeoxycholic acid (CDCA); the secondary unconjugated BAs ursodeoxycholic acid (UDCA), hyodeoxycholic acid (HDCA) and deoxycholic acid (DCA), as well as the glycine- and taurine-conjugated variants of CA, CDCA, DCA and UDCA. Donor blood was obtained to prepare DBS calibrators and quality controls for method development and validation. ResultsWe developed a quantitative bile acid assay with a run-time of two minutes, and one-step sample preparation of 3.2 mm DBS discs. Validation results demonstrated overall good performance and was considered fit for purpose. Children with Alagille syndrome, Aagenaes syndrome and alpha-1 antitrypsin deficiency had increased BAs in DBS from newborn screening samples compared with age matched controls, and had different bile acids profiles. ConclusionWe propose that our high throughput assay allows bile acid profiling in DBS that can be a valuable assessment tool for early screening of cholestasis in children. Assaying BAs in dried bloodspots is key for early detection of cholestasis, and provides transferability to a newborn screening setting.

A Review of Research Progress in Microfluidic Bioseparation and Bioassay.

With the rapid development of biotechnology, the importance of microfluidic bioseparation and bioassay in biomedicine, clinical diagnosis, and other fields has become increasingly prominent. Microfluidic technology, with its significant advantages of high throughput, automated operation, and low sample consumption, has brought new breakthroughs in the field of biological separation and bioassay. In this paper, the latest research progress in microfluidic technology in the field of bioseparation and bioassay is reviewed. Then, we focus on the methods of bioseparation including active separation, passive separation, and hybrid separation. At the same time, the latest research results of our group in particle separation are introduced. Finally, some application examples or methods for bioassay after particle separation are listed, and the current challenges and future prospects of bioseparation and bioassay are discussed.

Automated Liquid Handling Extraction and Rapid Quantification of Underivatized Amino Acids and Tryptophan Metabolites from Human Serum and Plasma Using Dual-Column U(H)PLC-MRM-MS and Its Application to Prostate Cancer Study.

Amino acids (AAs) and their metabolites are important building blocks, energy sources, and signaling molecules associated with various pathological phenotypes. The quantification of AA and tryptophan (TRP) metabolites in human serum and plasma is therefore of great diagnostic interest. Therefore, robust, reproducible sample extraction and processing workflows as well as rapid, sensitive absolute quantification are required to identify candidate biomarkers and to improve screening methods. We developed a validated semi-automated robotic liquid extraction and processing workflow and a rapid method for absolute quantification of 20 free, underivatized AAs and six TRP metabolites using dual-column U(H)PLC-MRM-MS. The extraction and sample preparation workflow in a 96-well plate was optimized for robust, reproducible high sample throughput allowing for transfer of samples to the U(H)PLC autosampler directly without additional cleanup steps. The U(H)PLC-MRM-MS method, using a mixed-mode reversed-phase anion exchange column with formic acid and a high-strength silica reversed-phase column with difluoro-acetic acid as mobile phase additive, provided absolute quantification with nanomolar lower limits of quantification within 7.9 min. The semi-automated extraction workflow and dual-column U(H)PLC-MRM-MS method was applied to a human prostate cancer study and was shown to discriminate between treatment regimens and to identify metabolites responsible for discriminating between healthy controls and patients on active surveillance.

A high-throughput supramolecular solvent method for benzophenone quantification in juice packs via liquid chromatography-mass spectrometry

Benzophenones (BPs) are among the most frequently detected photoinitiators in liquid packaged food, mainly using liquid chromatography tandem mass spectrometry (LC-MS/MS). However, sample treatments in these methods are demanding in terms of resources and expenses, are little or not sustainable, and prevent high throughput sample processing. In this paper, supramolecular solvents with properties of restricted access materials (SUPRAS-RAM) were firstly used to make simpler, faster and more sustainable the sample treatment in the determination of BPs in juices. The SUPRAS-RAM formed instantaneously in the juice by the addition of hexanol (75 µL) and tetrahydrofuran (600 µL). The BPs were extracted after vortexing the mixture for 2 min. Macromolecules in the sample, including carbohydrates, fibers and proteins were not extracted in the SUPRAS-RAM by physical or chemical mechanisms, so the extract could be directly injected into the LC-MS/MS system. Detection limits were in the range of 0.013–0.414ng mL−1. Average recoveries of BPs in juices (orange, tomato, pineapple, apple) at three concentration levels (1, 5 and 20ng mL−1) were 70.4–118 %, with relative standard deviations in the interval 0.05–9 %. Matrix effects were all in the range of ±20 %. Unlikely most of the reported methods for BPs based on LC-MS/MS, external calibration gave reliable quantification. Three BPs were detected and/or quantified in the ten juice samples analysed; namely benzophenone, 2-hydroxy-4-methoxybenzophenone and 4-methylbenzophenone. The characteristics of the sample treatment here proposed (i.e. low solvent consumption, integration of BP extraction and sample clean-up and a simple and fast procedure, and the effective removal of interferences) render this method competitive for BPs quantification with respect to previously reported methods.

Reproducible and high sample throughput isomiR next-generation sequencing for cancer diagnosis.

e15013 Background: Next-generation sequencing (NGS) can produce up to 6 Tb of data per run with single-nucleotide accuracy, making it ideal for quantifying isomiRs, which encompass both canonical miRNAs and their variants, for clinical applications. However, NGS has poor reproducibility and low sample throughput in quantifying circulating isomiRs due to significant technical variations and the limitations of the multiplex strategy, as evidenced by the fact that no isomiR NGS technique has been successfully used to diagnose cancer. Methods: To address these challenges, a library construction method including a dual unique-dual-index (DUDI) technology was developed. DUDI uses a pair of Inner UDI (IUDI) and outer UDI (OUDI) to label a sample. Twelve independent batches of isomiR NGS were carried out, including three repeated batches. Each batch included 100 gastric cancer and 100 control plasma samples. Batch effect, correlation coefficient (R), and principal component (PCA) analyses were used to evaluate technical reproducibility. Machine learning binary classification was used to assess biological reproducibility, with each pair of batch data serving interchangeably as both training and testing data. Results: In this multicenter study, over 700G of isomiR data were generated from 402 gastric cancer and 498 control samples, with a maximum error rate of 1 in 7 million isomiRs being assigned to wrong samples. The PCA plot indicates high technical reproducibility across the three repeated batches, shown by the extensive intermingling of data points from each batch and the lack of distinct batch-wise clustering. This observation is reinforced by that the R value for each of 239 isomiRs between the repeated batches are close to 1. While the mutual machine learning validations between the repeated batches yielded ~95% accuracy, indicating high biological reproducibility. The accuracies of the validations between the different batches of different samples range from 70% to 82%. The lower accuracy is as expected, given the high genetic heterogeneity of cancer and the small sample size. Furthermore, the IsomiR differentiated expression profiles from the current NGS study closely match those from prior qPCR studies. Conclusions: The DUDI library construction method can produce reproducible high sample throughput NGS data, yet it is cost-effective and straightforward. The maximum number of samples that can be multiplexed in an NGS project is almost one million, i.e., 976 * 976, as IUDI and OUDI can be any of the 976 designed DUDIs. This number far exceeds the high sample throughput requirements of any NGS application. While the capability to distinguish true biological variations of IsomiRs from technical noise, demonstrated by the high technical and biological reproducibility and concordance with the qPCR data, enables the development of robust machine learning algorithms for cancer diagnostics.

A highly sensitive, low input, and automated assay for molecular residual disease detection (MRD) using whole-genome sequencing (WGS).

3060 Background: Molecular residual disease (MRD) detection using cell-free DNA (cfDNA) for solid tumors requires a highly sensitive and specific assay that can overcome the limitation of low abundance circulating-tumor DNA (ctDNA) in a standard blood draw with fast sample-to-answer turn-around time (TAT). Here we describe the development and analytical performance of Illumina’s TruSight Oncology MRD WGS assay (TSO MRD, for research use only), for detecting MRD using tumor-informed whole-genome sequencing (WGS) of cfDNA extracted from plasma samples across multiple cancer types. Methods: The TSO MRD assay was built using Illumina’s best-in-class WGS library preparation, informatics and sequencing technologies. The assay is composed of two major steps, fingerprinting and ctDNA detection. At the fingerprinting step, the DNA from tumor tissue and matched normal samples is analyzed through WGS to generate a sample specific somatic variant list. At the ctDNA detection step, the cfDNA extracted from plasma is analyzed through shallow WGS and the presence of ctDNA is detected using the tumor specific fingerprint as an input in the MRD analysis pipeline. The plasma extraction and WGS library preparation workflows are fully automated for high-throughput sample processing with minimum hands-on time and touch points. Results: Testing of commercial MRD reference materials and ctDNA-positive samples serially diluted into normal cfDNA background demonstrated a limit of detection of down to 0.001% VAF or 10 parts per million (PPM) in multiple cancer types. Testing of a panel of normal plasma samples from healthy individuals assessed against 20 sets of fingerprints from multiple cancer types demonstrated an analytical specificity of 99.7%. Testing of ctDNA samples with multiple operators, instruments and library prep start days demonstrated high reproducibility in MRD detection. The ctDNA testing works at an optimal input amount of 5 ng and a minimum input amount down to 2 ng, which yields a high sample success rate from one standard 10 ml of blood draw. The TAT of the fingerprinting and the ctDNA detection steps is 5-7 days, respectively. Conclusions: The TSO MRD assay demonstrated high analytical sensitivity and specificity in detecting the presence of ctDNA from low input plasma samples with automated workflow and fast TAT. This assay enables a single streamlined solid tumor MRD platform for multiple cancer types.

Pipette tip-electrospray mass spectrometry for determining opioids in urine, from on-site micro-handling to high-throughput centrifugal microextraction

Pipette tip-electrospray is a useful technique that synergically combines sample preparation and ambient ionization mass spectrometry for the rapid analysis of samples. In this work, the development of pipette tip extraction (PTE) is evaluated under two workflows that can be adapted to different analytical scenarios. Micro-handling PTE (MH-PTE) is an inherently portable technique that can be on-site applied. Centrifugal PTE (C-PTE), firstly presented here, allows a high sample throughput just requiring a benchtop centrifuge. The combination of both MH-PTE and C-PTE with pipette tip-electrospray is evaluated in this work for determining codeine and morphine, two metabolically related drugs, in urine and applied to the analysis of real samples. In the case of MH-PTE, intended to be on-site applied, the chemical stability of the analytes once extracted in the tips plays a crucial role. This stability has been studied in detail, simulating several transport/storage conditions compatible with regular postal services. The analytical features of both combinations are similar, although C-PTE provides a better sensitivity in terms of limit of detection (0.3 µg L−1 for codeine and 0.6 µg L−1 for morphine) compared to MH-PTE (0.6 µg L−1 for codeine and 1.5 µg L−1 for morphine). Moreover, the sample throughput provided by C-PTE is higher (up to 72 samples h−1) than that provided by MH-PTE (up to 12 samples h−1).

Optimizing Zr-doped MC-ICP-MS sample-standard bracketing to simultaneously determine 87Sr/86Sr and δ88Sr for high sample-throughput

In recent years, the increasing demand for extensive strontium (Sr) datasets across various scientific fields has prompted the development of fast, precise, and reliable protocols. These protocols aim to achieve high sample-throughput without compromising data quality. A novel method termed the zirconium (Zr) doped sample-standard bracketing (SSB) has been recently introduced for isotope measurements using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). This method allows for simultaneous acquisition of 87Sr/86Sr and δ88Sr data without the need for sample spiking. However, the reliability of this method in handling large datasets and ensuring long-term reproducibility requires additional documentation. A comprehensive examination of the reliability of Sr isotope data over two years involves the implementation of systematic tests on reference materials from the National Institute of standards and technology (NIST) with the standard reference material (SRM) numbers: 1400, 1515, 987, 2910b, 1486, as well as a Hawaiian volcano observatory basalt (BHVO-1). The results of this study lead to the definition of a set of quality control parameters. The developed protocol applies various controls to ensure precise matching of Sr and Zr concentrations for both the samples and the bracketing standard (NIST SRM 987), along with the identification of instrumental biases. The outlined quality control ensures the reproducibility of the results (87Sr/86Sr = 0.710247 ± 0.000026, 2SD, n = 557; and δ88Sr = 0.001 ± 0.053 ‰, 2SD, n = 537 for NIST SRM 987), proving invaluable for archaeological, geological, and ecological studies requiring the fast acquisition of extensive datasets (n > 100) to create isotopic baselines.

Authentication of oats and discrimination from their gluten-containing adulterants using NIR diffuse reflectance spectroscopy and multivariate analysis

Oat (Avena sativa L.) is recognized for its nutritional value and gluten-free status, however, ensuring its authenticity and purity is crucial, given the potential for contamination with gluten-containing grains. In this study, near-infrared spectroscopy coupled with chemometrics were employed to authenticate oat flour (from different forms of oat; oat groats, steel-cut and rolled oats) and distinguish it from common gluten-containing adulterants including wheat, farro, triticale, barley, rye, and ryegrass. Both unsupervised and supervised chemometric methodologies, encompassing PCA, SIMCA, and OPLS-DA, were applied. Both SIMCA and OPLS-DA models displayed 100% sensitivity, enabling reliable identification of oat flour and detection of potential adulteration with these gluten-containing grains with specificity of 97.78% and 100%, respectively. In the SIMCA model for oat groats and adulterated mixtures, samples with 1% and 2% adulteration were incorrectly classified as oat groats, yet successful discrimination from deliberately-adulterated mixtures was accomplished through the OPLS-DA model with 100% specificity. Moreover, PLS regression analysis was employed to precisely quantify the levels of adulterants in oat groats flour. The models exhibited reliable performance, as reflected in Root Mean Square Error of Calibration (RMSEC) values. Validation of these models using test samples provided further confirmation of their efficacy in detecting sample adulteration and ensuring product authenticity, all while maintaining a high sample throughput rate.

High-throughput lipidomic profiles sampled with electroporation-based biopsy differentiate healthy skin, cutaneous squamous cell carcinoma, and basal cell carcinoma.

The incidence rates of cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC) skin cancers are rising, while the current diagnostic process is time-consuming. We describe the development of a novel approach to high-throughput sampling of tissue lipids using electroporation-based biopsy, termed e-biopsy. We report on the ability of the e-biopsy technique to harvest large amounts of lipids from human skin samples. Here, 168 lipids were reliably identified from 12 patients providing a total of 13 samples. The extracted lipids were profiled with ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS-MS) providing cSCC, BCC, and healthy skin lipidomic profiles. Comparative analysis identified 27 differentially expressed lipids (p<0.05). The general profile trend is low diglycerides in both cSCC and BCC, high phospholipids in BCC, and high lyso-phospholipids in cSCC compared to healthy skin tissue samples. The results contribute to the growing body of knowledge that can potentially lead to novel insights into these skin cancers and demonstrate the potential of the e-biopsy technique for the analysis of lipidomic profiles of human skin tissues.

Evaluation of in vitro bioaccessibility of Cu, Fe, Mn, and Zn from cooked Uruguayan pink shrimp by microwave induced plasma atomic emission spectrometry

Microwave induced plasma atomic emission spectrometry (MP-AES) was evaluated as a strategy for the analysis of simulated gastrointestinal solutions to estimate the in vitro bioaccessibility of essential elements in cooked pink shrimp. Operational conditions such as pump speed, nitrogen flow, and viewing position were thoroughly optimized for each element. Afterwards the validation of the analytical method was performed. Limits of quantification ranged from 0.005 mg kg−1 (Mn) to 0.106 mg kg−1 (Zn). Accuracy was evaluated by using a certified reference material and performing a mass-balance study. Suitable mass balances within the range 95–105% were obtained. In vitro bioaccessibility in cooked shrimp samples ranged from 14.7% (Fe) to 48.1% (Zn), in agreement with previous data from other shrimp species. The proposed procedure proved to be an outstanding sequential analytical strategy for elemental bioaccessibility studies, providing simplicity and high sample throughput compared to conventional approaches. Furthermore, this work constitutes the first work regarding the optimization of an elemental bioaccessibility study on animal protein employing MP-AES.

Exploring the Performance of Linear and Nonlinear Models of Time-of-Flight Secondary Ion Mass Spectrometry Spectra.

Multivariate statistical tools and machine learning (ML) techniques can deconvolute hyperspectral data and control the disparity between the number of samples and features in materials science. Nevertheless, the importance of generating sufficient high-quality sample replicates in training data cannot be overlooked, as it fundamentally affects the performance of ML models. Here, we present a quantitative analysis of time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra of a simple microarray system of two food dyes using partial least-squares (PLS, linear) and random forest (RF, nonlinear) algorithms. This microarray was generated by a high-throughput sample preparation and analysis workflow for fast and efficient acquisition of quality and reproducible spectra via ToF-SIMS. We drew insights from the bias-variance trade-off, investigated the performances of PLS and RF regression models as a function of training data size, and inferred the amount of data needed to construct accurate and reliable regression models. In addition, we found that the spectral concatenation of positive and negative ToF-SIMS spectra improved the model performances. This study provides an empirical basis for future design of high-throughput microarrays and multicomponent systems, for the purpose of analysis with ToF-SIMS and ML.

Functionalizing tandem mass tags for streamlining click-based quantitative chemoproteomics

Mapping the ligandability or potential druggability of all proteins in the human proteome is a central goal of mass spectrometry-based covalent chemoproteomics. Achieving this ambitious objective requires high throughput and high coverage sample preparation and liquid chromatography-tandem mass spectrometry analysis for hundreds to thousands of reactive compounds and chemical probes. Conducting chemoproteomic screens at this scale benefits from technical innovations that achieve increased sample throughput. Here we realize this vision by establishing the silane-based cleavable linkers for isotopically-labeled proteomics-tandem mass tag (sCIP-TMT) proteomic platform, which is distinguished by early sample pooling that increases sample preparation throughput. sCIP-TMT pairs a custom click-compatible sCIP capture reagent that is readily functionalized in high yield with commercially available TMT reagents. Synthesis and benchmarking of a 10-plex set of sCIP-TMT reveal a substantial decrease in sample preparation time together with high coverage and high accuracy quantification. By screening a focused set of four cysteine-reactive electrophiles, we demonstrate the utility of sCIP-TMT for chemoproteomic target hunting, identifying 789 total liganded cysteines. Distinguished by its compatibility with established enrichment and quantification protocols, we expect sCIP-TMT will readily translate to a wide range of covalent chemoproteomic applications.

Methodology for high-performance liquid chromatography detection of latanoprost and latanoprost free acid

AbstractA gradient high-performance liquid chromatography (HPLC) method has been developed to determine the concentrations of latanoprost (LP) and latanoprost free acid (LPA) in aqueous solutions. It is novel due to a combination of its simplicity, speed, and detection capability in aqueous solutions for both active drug (LPA) and prodrug (LP). This method is applicable for the research and development of novel drug delivery devices and quality control assays for experimental and commercial laboratory settings, as it allows for a high sample throughput. Samples were chromatographed across a C18 + 2.7 µm 4.6 × 7.5 mm reversed-phase column with gradient elution using a mobile phase of aqueous acetic acid (pH 3.1) and acetonitrile with 0.1% acetic acid. UV spectrophotometry was used to monitor the eluents at 210 nm. Drug concentrations from 1.0 to 150 μg mL−1 were tested, with good linearity observed across the range. LPA had a signature peak at approximately 4.82 min (SD &lt; 0.08) and LP at 9.27 min (SD &lt; 0.07). For both drug and pro-drug, LOD and LOQ were 1.0 and 2.5 μg mL−1, respectively. This assay which accurately measures both prodrug and drug in a single injection, has significant applicability in determining the release kinetics of novel LP drug delivery systems.

An integrated method for rapid extraction of fluorescent whitening agents from selected cosmetics by in situ formation of deep eutectic solvent

A novel extraction methodology was developed based on deep eutectic solvent (DES) in situ formation. The solvent was synthesized from a binary mixture of L-cysteine, functioning as a hydrogen bond acceptor, and 2-methylphenol, serving as a hydrogen bond donor. The DES’s inherent molecular structures and extensive hydrogen bonding networks were characterized using the Fourier-transform infrared spectroscopy (FT-IR), while its hydrophobic nature was assessed by determining molecular polarity. Its extraction efficiency was demonstrated through the extraction of fluorescent whitening agents (FWAs) in cosmetic products, acting as a model analytical application. This was accomplished using vortex-assisted emulsification solid–liquid extraction (SLE) method, followed by high-performance liquid chromatography-fluorescence detection. Response surface methodology was employed to optimize extraction conditions in a multivariate experimental design. This approach streamlined the multi-operation extraction process via ingeniously integrating extraction and clean-up into a single step, resulting in significant reductions in extraction time required and high sample throughputs of approximately 40 samples per hour. The methodology was validated and exhibited excellent linearity in concentration ranges of 0.01–24 mg/L for five FWAs and 0.01–40 mg/L for other three FWAs, with correlation coefficients (r) ranging from 0.9985 to 1.000. The limits of detection and quantification were in the range of 0.03–0.26 mg kg−1 and 0.10–0.87 mg kg−1, respectively. The reliability and practicality of the proposed method were affirmed by quantifying eight FWAs in ninety-four commercially available facial masks and whitening creams, yielding recoveries values between 90.0 % and 106.0 % with relative standard deviations (RSDs) of 1.0–4.3 %. Inorganic ions and organic compounds present in the samples had minimal impact on FWAs detection following sample pre-treatment. This procedure showcased exceptional extraction capabilities towards a diverse array of FWAs with the aid of multiple interactions, suggesting significant potential for increasing sample throughput while reducing organic solvent and material consumptions compared with conventional SLE methods. The low-toxicity DES is an excellent alternative to traditional extractants typically applied to SLE techniques.

High throughput application of ASTM D8332: Detailed prototype design and operating conditions for microplastic sampling of riverine systems

Microplastic sampling strategies for aquatic systems commonly employ small mesh nets to collect suspended microparticles. These methods work well for marine sampling campaigns; however, complex water systems such as freshwater rivers, effluent discharges, and stormwater ponds characterized by high total suspended solids and fast-moving water can cause the nets to clog, rip, or tear. Published in 2020, ASTM D8332 is an alternative approach to sampling complex water systems for microplastics involving pumping large volumes of water across a cascading stack of sieves to collect suspended particles. Here we show that ASTM D8332 can be applied to sample freshwater rivers for microplastic collection. A high throughput sampling prototype developed in this work is capable of pumping 1500 L of river water in 45 min to collect particles as small as 45 µm. The system is lightweight, modular, and easily transportable. It has a discrete power supply, allowing for the collection of microplastics anywhere along the river, including municipal discharges. The design minimizes the amount of plastic in the flow path and provides a practical way to measure field contamination. Finally, we outline lessons learned through extensive field trials and testing using this system sampling the North Saskatchewan River in Edmonton, Alberta.•Existing small mesh nets face limitations in freshwater rivers, encountering clogging and tearing issues from high suspended solids and fast moving water.•Using a standardized method, ASTM D8332 - a pumping-based approach is efficient for microplastic collection in freshwater rivers.•Lightweight, modular, plastic free prototype system pumps 1500 L of river water in 45 min, collecting particles as small as 45 µm. Successfully tested in the North Saskatchewan River.

Room-temperature fabrication of fluorinated covalent organic polymer @ Attapulgite composite for in-syringe membrane solid-phase extraction and analysis of domoic acid in aquatic products

A novel fluorinated covalent organic polymer @ attapulgite composite (F-COP@ATP) was prepared at room temperature for in-syringe membrane solid-phase extraction (SM-SPE) of domoic acid (DA) in aquatic products. Natural ore ATP has the advantages of low cost, good mechanical strength and abundant hydroxyl group on its surface, and in-situ modified F-COP layer can provide abundant adsorption sites. F-COP@ATP combining the advantages of F-COP and ATP, becomes an ideal adsorbent for DA extracting. Moreover, a high-throughput sample preparation strategy was carried out by using the F-COP@ATP membrane as syringe filter and assembling syringes with a ten-channel injection pump. In addition, the experimental factors were optimized, such as pH of extract, amount of adsorbent, velocity of extraction and desorption, type and volume of desorption solvent. The DA analytical method was established by SM-SPE-HPLC/tandem mass spectrometry. The method had a wide linear range with low limit of detection (0.344 ng/kg) and low limit of quantification (1.14 ng/kg). F-COP@ATP membrane can be reused more than five times. The method realized the analysis of DA in scallop and razor clam samples, which shows its application prospect in practical analysis. This study provided an efficient, low-energy and mild idea for preparing other reusable natural mineral ATP-based composite materials for separation and enrichment, which reduces the experimental cost and is closer to environmental protection and green chemistry to a certain extent.