The sensitivity of complex analytical procedures depends not only on the sensitivity of the analytical instrument used, but also on the recovery degree of the examined analyte by the employed sample ...preparation method. The recovery degrees of individual cannabinoids reported in literature, estimated using the same sample preparation method, are unexpectedly divergent. Therefore, the aim of this study was a thorough assessment of the most commonly used sample preparation methods, such as protein precipitation, LLE, QuEChERS and SPE, in the context of the reliability of the obtained results. The presented report shows that the highest sensitivity, precision and reliability of the chromatographic analysis of CBG, CBD, ∆9-THC and CBN in human plasma can be obtained using SPE. The recovery degrees of these cannabinoids by SPE are highly repeatable and exceed 95 %, while they are significantly lower for such sample preparation methods as protein precipitation, LLE and QuEChERS (ca. 80, 65 and 87, respectively). Moreover, the supernatants obtained by the latter methods contain interferents evoking matrix-effect, which makes reliable quantification of the listed cannabinoids by GC difficult. To our knowledge, the paper is the first such extensive comparison of sample preparation procedures used for the determination of cannabinoids in plasma by GC-MS and HPLC-MS. The presented results and the discussion allow to understand why different recovery degrees for the same xenobiotic can be find in literature despite they have been estimated using the same or different sample preparation method or different chromatography types.
Display omitted
•Analyte recovery degree as a key factor in analytical procedure of complex mixtures.•SPE gives almost 100 % recovery of cannabinoids from blood plasma.•SPE allows for reliable analysis of cannabinoids in blood/plasma by GC and HPLC.•Plasma LLE and QuEChERS supernatants contain interferents evoking matrix effect in GC.
A simplified sample preparation method in combination with gas chromatography–triple-quadrupole mass spectrometry (GC-MS/MS) analysis was developed and validated for the simultaneous determination of ...227 pesticides in green tea, ginseng, gingko leaves, saw palmetto, spearmint, and black pepper samples. The botanical samples were hydrated with water and extracted with acetonitrile, magnesium sulfate, and sodium chloride. The acetonitrile extract was cleaned up using solid phase extraction with carbon-coated alumina/primary–secondary amine with or without C18. Recovery studies using matrix blanks fortified with pesticides at concentrations of 10, 25, 100, and 500 μg/kg resulted in average recoveries of 70–99% and relative standard deviation of 5–13% for all tested botanicals except for black pepper, for which lower recoveries of fortified pesticides were observed. Matrix-matched standard calibration curves revealed good linearity (r 2 > 0.99) across a wide concentration range (1–1000 μg/L). Nine commercially available tea and 23 ginseng samples were analyzed using this method. Results revealed 36 pesticides were detected in the 9 tea samples at concentrations of 2–3500 μg/kg and 61 pesticides were detected in the 23 ginseng samples at concentrations of 1–12500 μg/kg.
Analytical processes involving sample preparation, separation, and quantifying analytes in complex mixtures are indispensable in modern-day analysis. Each step is crucial to enriching correct and ...informative results. Therefore, sample preparation is the critical factor that determines both the accuracy and the time consumption of a sample analysis process. Recently, several promising sample preparation approaches have been made available with environmentally friendly technologies with high performance. As a result of its many advantages, solid-phase extraction (SPE) is practiced in many different fields in addition to the traditional methods. The SPE is an alternative method to liquid–liquid extraction (LLE), which eliminates several disadvantages, including many organic solvents, a lengthy operation time and numerous steps, potential sources of error, and high costs. SPE advanced sorbent technology reorients with various functions depending on the structure of extraction sorbents, including reversed-phase, normal-phase, cation exchange, anion exchange, and mixed-mode. In addition, the commercial SPE systems are disposable. Still, with the continual developments, the restricted access materials (RAM) and molecular imprinted polymers (MIP) are fabricated to be active reusable extraction cartridges. This review will discuss all the theoretical and practical principles of the SPE techniques, focusing on packing materials, different forms, and performing factors in recent and future advances. The information about novel methodological and instrumental solutions in relation to different variants of SPE techniques, solid-phase microextraction (SPME), in-tube solid-phase microextraction (IT-SPME), and magnetic solid-phase extraction (MSPE) is presented. The integration of SPE with analytical chromatographic techniques such as LC and GC is also indicated. Furthermore, the applications of these techniques are discussed in detail along with their advantages in analyzing pharmaceuticals, biological samples, natural compounds, pesticides, and environmental pollutants, as well as foods and beverages.
Graphical abstract
This study provides the first EU-wide reconnaissance of the occurrence of polar organic persistent pollutants in European river waters. More than 100 individual water samples from over 100 European ...rivers from 27 European Countries were analysed for 35 selected compounds, comprising pharmaceuticals, pesticides, PFOS, PFOA, benzotriazoles, hormones, and endocrine disrupters. Around 40 laboratories participated in this sampling exercise. The most frequently and at the highest concentration levels detected compounds were benzotriazole, caffeine, carbamazepine, tolyltriazole, and nonylphenoxy acetic acid (NPE
1C). Only about 10% of the river water samples analysed could be classified as “very clean” in terms of chemical pollution. The rivers responsible for the major aqueous emissions of PFOS and PFOA from the European Continent could be identified. For the target compounds chosen, we are proposing “indicative warning levels” in surface waters, which are (for most compounds) close to the 90th percentile of all water samples analysed.
More than 100 river water samples from 27 European Countries were analysed for 35 selected polar organic contaminants.
Dissolved organic carbon (DOC) in the global oceans is an important long‐term carbon sink. Connections between molecular size, reactivity, and isotopic characteristics show that DOC exists on a ...continuum from biologically reactive to recalcitrant. The driving mechanisms behind the creation and persistence of recalcitrant DOC remain unknown. We show mean recalcitrant DOC (isolated via solid‐phase extraction; SPE‐DOC) δ13C values are 1.3 ± 0.6‰ lower than mean total DOC δ13C between depth ranges 0–200 m and 2–4 km on three GO‐SHIP Repeat Hydrography cruises. Lowest observed δ13C values correlate with low ∆14C and proximity to deep ocean hydrothermal systems. These data support the hypothesis that reworking of DOC through the microbial carbon pump is a key driver of the ocean's long‐term carbon sink. Mass‐balance modeling shows deep‐ocean DOC not captured by SPE is enriched in 13C, highlighting the need for continued research on non‐retained DOC to predict mechanisms that drive ocean carbon storage.
Plain Language Summary
The global oceans play an important role in Earth's climate, and dissolved organic carbon (DOC) (produced by surface ocean photosynthesis) has been recognized as a potential long‐term carbon sink in the deep ocean. However, the mechanisms behind the long‐term sink remain unknown. Recent research has shown that a phenomenon called the microbial carbon pump (MCP) may be a driving force in the production of long‐lasting “recalcitrant” DOC via heterotrophic consumption of nitrogen and phosphorus rich biomolecules and subsequent production of recalcitrant DOC as by‐product. The work presented here shows that this phenomenon, previously recognized on regional scales, may be systematic across the global oceans, indicated by our measurements in the Pacific, Indian, and Southern Oceans.
Key Points
Solid‐phase extracted dissolved organic carbon has low isotope signatures relative to bulk dissolved organic carbon in three ocean basins
This research supports the hypothesis that bacteria drive the storage of recalcitrant organic matter through successive reworking
Isotope measurements show hydrothermal vent influence likely captured in deep‐ocean solid‐phase extracted dissolved organic carbon
Recent developments in coupled SPE-CE Ramautar, Rawi; Somsen, Govert W; de Jong, Gerhardus J
Electrophoresis,
January 2010, Letnik:
31, Številka:
1
Journal Article
Recenzirano
This article presents an overview of coupled SPE-CE systems that have been reported in the literature between April 2007 and June 2009. The use of in-line and on-line SPE-CE is covered in this ...review. Special attention is paid to the use of monoliths and molecularly imprinted polymers in coupled SPE-CE systems. Application-oriented research is discussed in which in-line and on-line SPE-CE systems have been used in biomedical, pharmaceutical, environmental and food analysis. The SPE-CE studies are presented in tables, including information on sample type, SPE sorbent, detection and LOD. Finally, some future developments that may increase the applicability of coupled SPE-CE are highlighted.
•SPE/QuEChERS is a simple sample treatment for pesticides testing in edible oils.•The Z-Sep sorbent containing ZrO2 allows efficient clean-up of extracts.•Recovery values of 64% of pesticides for ...olive oil samples ranged from 50% to 130%.•The validated method was successfully employed in the analysis of edible oils samples selected from the market.
In this study, the solid-phase extraction/quick, easy, cheap, effective, rugged and safe (SPE/QuEChERS) technique was adapted to develop a simple sample treatment for multi-residue pesticide analysis of edible oils. The proposed method is based on liquid–liquid partitioning with acetonitrile followed by dispersive solid phase extraction using zirconia-coated silica particles for extract purification. To evaluate the described method, 21 pesticides belonging to different chemical classes were analysed using high performance liquid chromatography with diode-array detection (HPLC–DAD). For validation purposes, recovery studies were performed at 75ngg−1, 125ngg−1, 250ngg−1, 500ngg−1 and 1000ngg−1 levels. Recoveries were over the range of 50–130% for most of the analytes, with relative standard deviations less than 15% being observed. HPLC–DAD provided suitable linearity, precision and accuracy. The validated method was successfully applied to the analysis of edible oil samples selected from the market.
According to the World Health Organization, >360 million people worldwide suffer from mental diseases such as depression, anxiety, or bipolar disorder, for which psychotropic drugs are frequently ...prescribed. Despite being highly metabolized in the human organism, non-metabolized portions of these drugs are excreted, subsequently reaching wastewater treatment plants (WWTPs), where they may be incompletely removed during treatment, leading to the contamination of surface waters. In this work, ten psychotropic drugs widely consumed in Brazil (alprazolam, amitriptyline, bupropion, carbamazepine, clonazepam, escitalopram, fluoxetine, nortriptyline, sertraline, and trazadone) were monitored at five WWTPs located in the metropolitan region of Campinas (São Paulo State, Brazil). The drugs were determined in the influents, at different stages of the treatments, and in the effluents. Surface waters from the Atibaia River and the Anhumas Creek were also monitored. Quantitation of the pharmaceuticals was carried out by online solid-phase extraction coupled with ultra-high performance liquid chromatography and tandem mass spectrometry. The method was validated and presented a limit of quantitation of 50 ng L−1 for all the drugs assessed. Six of the substances monitored were quantified in the samples collected from the different treatment processes employed at the WWTPs. These technologies were unable to act as barriers for these psychotropics drugs. The concentrations ranged from 50 to 3000 ng L−1 in the WWTP effluents, while the main contaminants were found in surface waters at concentrations from 25 to 3530 ng L−1. The levels of the psychotropic detected in this work did not appear to present risks to the aquatic biota.
Display omitted
•10 Psychotropics drugs were prioritized for monitoring in water and WWTPs.•The validated SPE-UHPLC-MSMS method presented a LOQ of 50 ng L−1.•Psychotropics drugs were detectable at ppt levels in superficial water.•WWTPs did not work as a barrier to remove psychotropics from effluents.•The occurrence levels of psychotropics do not pose risk for the biota.
The study aimed to develop a rapid and sensitive colorimetric platform based on the Emerson reaction to visualize and determine total aflatoxins (AFs) in peanut oil. This method offers the advantage ...of fast screening for AFs (AFB1, AFB2, AFG1, and AFG2), eliminating the need for specific antibodies. The proposed approach combined colorimetric detection with magnetic dummy imprinted solid-phase extraction and purification, enhancing sensitivity and selectivity. The oxidizer aided the colorless AFs in reacting with 4-aminoantipyrine, producing green condensates. Thus, a dual-mode approach was developed for AFs detection, employing both UV–vis colorimetric and smartphone-based colorimetry. Both methods showed a good linear relationship with the concentration of AFs. Notably, the smartphone-based method demonstrated a detection range of 0.5–57 μg/kg, with a detection limit as low as 0.21 μg/kg. The suggested colorimetric methods present a promising potential for onsite detection and fast screening of AFs in actual samples.
•A colorimetric method based on the Emerson reaction was developed for aflatoxins.•Colorimetric method coupled with MSPE was applied for the analysis of aflatoxins.•Smartphone-enabled visual platform was established with excellent sensitivity.•This method was successfully applied to detection of aflatoxins in peanut oil.
Acrylamide (AA) is a process-contaminant formed during Maillard Reaction (MR) in starchy foods heated at temperatures above 120 °C. It has been classified by the International Agency for Research on ...Cancer (IARC) as a probable carcinogen (2A) and genotoxic substance. Detecting AA in a reliable, rapid, cost-effective, and sustainable manner is crucial. This article reviews the most commonly used techniques for extracting and quantifying AA in various food samples, while also discussing the latest innovative techniques and future trends in AA analysis. In recent years, innovative extraction methods have been developed to improve selectivity for AA compared to traditional techniques that require Internal Standards (IS) and highly sensitive quantification methods. This is particularly important due to the complex nature of food matrices. The critical step in AA quantification lies in purifying the aqueous extract because AA is highly soluble in water and coexists with other polar compounds. Innovative solvent-free techniques offer advantages such as improved selectivity, efficiency, and cost-effectiveness. They can also reduce the need for extensive sample preparation and minimize the interference of other compounds present in the food matrices. In addition, modified QuEChERS extraction techniques have been proposed, which involve a significant reformulation of the commonly used methods. As research in this field continues to evolve, it is expected that future trends will focus on further improving the accuracy, sensitivity and sustainability of AA detection, ultimately contributing to food safety and consumer health.
•Purification of aqueous extract is a critical point for acrylamide determination.•Internal standard and highly sensitive detection techniques, such as mass spectrometry are necessary.•Dummy Molecularly Imprinted Polymers or Accelerated Solvent Extraction are innovative, selective and environmentally sustainable techniques.•Dummy Molecularly Imprinted Polymers or Accelerated Solvent Extraction can avoid or minimize the use of organic solvents.
