This review critically assesses the determination of low molecular weight volatiles by different methods, providing context for the development of suitable techniques to determine volatile content in plant tissue and soil samples as well as the associated analytical challenges. Although sensitive analytical methods have been reported in recent decades, studies on their application in modern investigative techniques are lacking. Herein, the latest sampling methods in volatile biochemistry, current advancements in the understanding of these analytes, and the significance of these findings for other types of volatiles are summarized. Gas chromatography, high-performance liquid chromatography, ion chromatography, thin-film microextraction, and real-time monitoring techniques are discussed and critically determined. This review concerns the methods most suitable for future research in this area.

A thorough evaluation of the quality, reproducibility, and variability of bottom-up proteomics data is necessary at every stage of a workflow, from planning to analysis. We share vignettes applying adaptable quality control (QC) measures to assess sample preparation, system function, and quantitative analysis. System suitability samples are repeatedly measured longitudinally with targeted methods, and we share examples where they are used on three instrument platforms to identify severe system failures and track function over months to years. Internal QCs incorporated at the protein and peptide levels allow our team to assess sample preparation issues and to differentiate system failures from sample-specific issues. External QC samples prepared alongside our experimental samples are used to verify the consistency and quantitative potential of our results during batch correction and normalization before assessing biological phenotypes. We combine these controls with rapid analysis (Skyline), longitudinal QC metrics (AutoQC), and server-based data deposition (PanoramaWeb). We propose that this integrated approach to QC is a useful starting point for groups to facilitate rapid quality control assessment to ensure that valuable instrument time is used to collect the best quality data possible. Data are available on Panorama Public and ProteomeXchange under the identifier PXD051318.

Emerging pollutants pose an increasing threat to the environment and human well-being, requiring substantial progress in analytical methodologies. Dispersive micro-solid phase extraction (μ-dSPE) has proven successful in detecting and measuring these contaminants, particularly in trace quantities. However, challenges persist in achieving a uniform sorbent distribution and efficient separation from the sample matrix. To address these issues, effervescent-assisted dispersive micro-solid phase extraction (EA-μ-dSPE) was developed. This method uses on-site produced carbon dioxide as a dispersing agent, eliminating the need for vortexing or ultrasonication. Due to the sorbent dispersion in the sample solution, the contact surface between the analyte and the sorbent increases, resulting in increased extraction efficiency, reduced extraction time, and promotes of sustainability. Several parameters are critical to the successful execution of this procedure to extract the analytes, including the type and structure of sorbent, composition of dispersing agents, sorbent separation procedure, and type and properties of desorption solvents. The sorbent plays a critical role in successful extraction of emerging pollutants. It is clear that for the extraction of the analyte on the sorbent, proper interaction must be established between the analyte and the sorbent via physical and chemical interactions. This review thoroughly evaluates the underlying principles of the approach, its potential, and the significant advancements that have been documented. It explores the method\'s capacity to analyse and identify emerging pollutants, emphasising its potential across various sample matrices for enhanced pollutant identification and quantification.

In this work, an easy, safe, simple, and efficient pH-switchable deep eutectic solvents (DESs)-based liquid phase microextraction followed by high-performance liquid chromatography-diode array detector analysis was developed for the determination of 1,3-dimethylamylamine (DMAA). The switchability of the obtained DESs was investigated by changing the pH. Then the best-selected DES was characterized and the application of the selected DES in the extraction of DMAA from sports nutrition and bodybuilding supplements was investigated. The DES synthesized from l-menthol: oleic acid in a molar ratio of 1:2 had the highest efficiency in the extraction of the target compound. Under the optimum conditions, (50 µL of DES, 100 µL of 4 mol/L KOH, 100 µL of 4 mol/L HCl, extraction time of 40 s and without salt addition) the calibration graph was linear in the range of 0.05-100 µg/kg and limit of detection was 0.02 µg/kg. The relative standard deviations including intra-day and inter-day for 10.0 µg/kg of DMAA in real samples were 2.7% (n = 7) and 5.3% (n = 7), respectively. The enrichment factor and percentage extraction recovery of the method were 283 and 85%, respectively. The relative recoveries for DMAA in different samples were in the range of 90%-109%.

Bottom-up proteomics utilizes sample preparation techniques to enzymatically digest proteins, thereby generating identifiable and quantifiable peptides. Proteomics integrates with other omics methodologies, such as genomics and transcriptomics, to elucidate biomarkers associated with diseases and responses to drug or biologics treatment. The methodologies employed for preparing proteomic samples for mass spectrometry analysis exhibit variability across several factors, including the composition of lysis buffer detergents, homogenization techniques, protein extraction and precipitation methodologies, alkylation strategies, and the selection of digestion enzymes. The general workflow for bottom-up proteomics consists of sample preparation, mass spectrometric data acquisition (LC-MS/MS analysis), and subsequent downstream data analysis including protein quantification and differential expression analysis. Sample preparation poses a persistent challenge due to issues such as low reproducibility and inherent procedure complexities. Herein, we have developed a validated chloroform/methanol sample preparation protocol to obtain reproducible peptide mixtures from both rodent tissue and human cell line samples for bottom-up proteomics analysis. The protocol we established may facilitate the standardization of bottom-up proteomics workflows, thereby enhancing the acquisition of reliable biologically and/or clinically relevant proteomic data. Key features • Tissue/cell pellet sample preparation for bottom-up proteomics. • Chloroform/methanol protein extraction from murine tissue samples. • In-solution trypsin digestion proteomics workflow.

The current paper reports two new, robust, and efficient conditions for electromembrane extraction of acidic substances from human plasma. Two systems were developed based on eutectic solvents: A1 (\"A\" for acid) comprised dodecyl methyl sulfoxide and thymol in 1:2 ratio (w/w) as liquid membrane, while A2 used [6-methylcoumarin:thymol (1:2)]:2-nitrophenyl octyl ether in 2:1 ratio (w/w). The performance of A1 and A2 was characterized by extraction of 31 acidic model analytes (pharmaceutical drugs and nutrients) spiked into 100 µL human plasma diluted 1:1 (v/v) with phosphate buffer pH 7.4. The acceptor solution was 50 mM NH4HCO3 buffer pH 10.0, and extraction was performed at an agitation rate of 750 RPM. Voltage and extraction time were 30 V for 30 min and 10 V for 20 min for A1 and A2, respectively. Under optimal conditions, A1 extracted analytes with 1.8 ≤ log P ≤ 6.0 with an average recovery (R) of 85.1%, while A2 extracted in a range of 0.5 ≤ log P ≤ 6.0 with an average recovery of 79.9%. Meanwhile, extraction current was low at 9 and 26 µA, respectively, which is indicative of good system robustness. Using UHPLC-MS/MS analysis of the acceptor solution, repeatability of the A1 and A2 methods was determined to be 2.8-7.7% and 3.3-9.4% for R > 40%, matrix effects were 82-117% and 84-112%, respectively, and linear calibration curves were obtained. The performance and compatibility with human plasma represent a major improvement over previous state-of-the-art liquid membranes for acidic analytes, namely 1-octanol.

Among the various compounds regarded as emerging contaminants (ECs), pharmaceuticals and personal care products (PPCPs) are of particular concern. Their continuous release into the environment has a negative global impact on human life. This review summarizes the sources, occurrence, persistence, consequences of exposure, and toxicity of PPCPs, and evaluates the various analytical methods used in the identification and quantification of PPCPs in a variety of solid and liquid environmental matrices. The current techniques of choice for the analysis of PPCPs are state-of-the-art liquid chromatography coupled to mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS2). However, the complexity of the environmental matrices and the trace levels of micropollutants necessitate the use of advanced sample treatments before these instrumental analyses. Solid-phase extraction (SPE) with different sorbents is now the predominant method used for the extraction of PPCPs from environmental samples. This review also addresses the ongoing analytical method challenges, including sample clean-up and matrix effects, focusing on the occurrence, sample preparation, and analytical methods presently available for the determination of environmental residues of PPCPs. Continuous development of innovative analytical methods is essential for overcoming existing limitations and ensuring the consistency and diversity of analytical methods used in investigations of environmental multi-class compounds.

The analysis of biological samples is highly valuable for disease diagnosis and treatment, forensic examination, and public safety. However, the serious matrix interference effect generated by biological samples severely affects the analysis of trace analytes. Sample preparation methods are introduced to address the limitation by extracting, separating, enriching, purifying trace target analytes from biological samples. With the raising demand of biological sample analysis, a review focuses on media for biological sample preparation and analysis over the last 5 years is presented. High-performance media in biological sample preparation are first reviewed, including porous organic frameworks, imprinted polymers, hydrogels, ionic liquids, and bioactive media. Then, application of media for different biological sample preparation and analysis is briefly introduced, including liquid samples of body fluids, solid samples (hair, feces, and tissues), and gas samples of exhale breath gas. Finally, conclusions and outlooks on media promoting biological sample preparation are presented.

Solid state NMR (SSNMR) is a highly versatile and broadly applicable method for studying the structure and dynamics of biomolecules and materials. For scientists entering the field of SSNMR, the many quotidian activities required in the workflow to prepare samples for data collection can present a significant barrier to adoption. These steps include transfer of samples into rotors, marking the reflective surfaces for high sensitivity tachometer signal detection, inserting rotors into the magic-angle spinning (MAS) stator, achieving stable spinning, and removing and storing rotors to ensure reproducibility of data collection conditions. Even experienced spectroscopists experience occasional problems with these operations, and the cumulative probability of a delay to successful data collection is high enough to cause frequent disruptions to instrument schedules, particularly in the context of large facilities serving a diverse community of users. These problems are all amplified when utilizing rotors smaller than about 4 mm in diameter. Therefore, to improve the reliability and robustness of SSNMR sample preparation workflows, here we describe a set of tools for rotor packing, unpacking, tachometer marking, extraction and storage. Stereolithography 3D printing was employed as a cost-effective and convenient method for prototyping and manufacturing a full range of designs suitable for several types of probes and rotor geometries.

Sample preparation in an analytical sequence increases the number of errors, is highly time-consuming, and involves the manipulation of hazardous reagents. Therefore, when an improvement in an analytical method is required, the sample preparation step needs to be optimised or redesigned. Moreover, this step can involve significant toxic reagents and a high volume of waste. In that regard, this study proposes a new procedure based on microwave-assisted wet digestion combining two green strategies: a miniaturised system (with a few microlitres of volume) and the only use of hydrogen peroxide. Three biological samples (human serum, urine, and plant in vitro material) were chosen due to their high potential for disease monitoring, toxicological studies, and biotechnology applications. Several trace elements (Ca, Cd, Co, Cu, Fe, Mg, Mn, Mo, Ni, Se, and Zn) were determined by inductively coupled plasma optical emission spectroscopy and inductively coupled plasma mass spectrometry. For human serum and urine, a certified reference material was used to check for accuracy; the recovery ranged from 72% (Cd, ICP-MS) to 105% (Mg, ICP OES) for serum, while for urine, they varied from 82% (Ni, ICP-MS) to 122% (Zn, ICP-MS). For the soybean callus sample (in vitro plant material), a comparison between the proposed method and the acid digestion method was conducted to evaluate the accuracy, and the results agreed. The detection limits were 0.001-60 µg L-1 (lowest for Cd), thus demonstrating a suitable sensitivity. Moreover, the decomposition efficiency was demonstrated by determining the residual carbon, and a low amount was found in the final product digested (below 0.8% w v-1). A green metric approach was calculated for the proposed method, and according to AGREEprep software, it was found to be around 0.4. Finally, the method was applied to urine samples collected in patients with COVID-19 and soybean callus cultivated with silver nanoparticles. This sample preparation method is a new acidless and miniaturised alternative for elemental analysis involving biological samples.