Complex Solid Matrices Research Articles

A free elution immunoassay for chloramphenicol in chicken and egg after magnetic ZIF-8 adsorption separation

The excellent adsorption and rapid separation capabilities of magnetic MOFs make them desirable pretreatment materials for solid substrates. In this study, magnetic ZIF-8 (mZIF-8) was synthesized in situ by a one-step method in the aqueous solution of magnetic beads. Isothermal adsorption verified that the maximum adsorption capacity of (011) crystal-exposed rhombic dodecahedral ZIF-8 for chloramphenicol was up to 128.31 mg/g (mZIF-8 = 67.18 mg/g). Kinetic adsorption revealed that the type of ZIF-8/mZIF-8 adsorption on chloramphenicol belongs to the pseudo-secondary adsorption kinetics of chemical monomolecular layers. Characterization by FTIR, XPS, and XRD revealed that mZIF-8 interacts with chloramphenicol mainly by π-π electron stacking, electrostatic attraction, and hydrogen bonding interaction. ELISA confirmed that chloramphenicol remained antigenically active after adsorption by mZIF-8. The adsorption and separation of chloramphenicol residues in chicken and egg were completed by mZIF-8 within 20 min. mZIF-8 can be used directly for elution-free ELISA after the adsorption of chloramphenicol. The limits of detection (IC10) of the mZIF-8 + ELISA in chicken and eggs were 1.18 ng/mL and 0.64 ng/mL, respectively. mZIF-8 is expected to be used as a magnetic solid-phase extraction material for the rapid pretreatment of antibiotic residues in other complex solid matrices.

A New Approach for Investigating Iron Mineral Transformations in Soils and Sediments Using 57Fe-Labeled Minerals and 57Fe Mössbauer Spectroscopy.

Iron minerals in soils and sediments play important roles in many biogeochemical processes and therefore influence the cycling of major and trace elements and the fate of pollutants in the environment. However, the kinetics and pathways of Fe mineral recrystallization and transformation processes under environmentally relevant conditions are still elusive. Here, we present a novel approach enabling us to follow the transformations of Fe minerals added to soils or sediments in close spatial association with complex solid matrices including other minerals, organic matter, and microorganisms. Minerals enriched with the stable isotope 57Fe are mixed with soil or sediment, and changes in Fe speciation are subsequently studied by 57Fe Mössbauer spectroscopy, which exclusively detects 57Fe. In this study, 57Fe-labeled ferrihydrite was synthesized, mixed with four soils differing in chemical and physical properties, and incubated for 12+ weeks under anoxic conditions. Our results reveal that the formation of crystalline Fe(III)(oxyhydr)oxides such as lepidocrocite and goethite was strongly suppressed, and instead formation of a green rust-like phase was observed in all soils. These results contrast those from Fe(II)-catalyzed ferrihydrite transformation experiments, where formation of lepidocrocite, goethite, and/or magnetite often occurs. The presented approach allows control over the composition and crystallinity of the initial Fe mineral, and it can be easily adapted to other experimental setups or Fe minerals. It thus offers great potential for future investigations of Fe mineral transformations in situ under environmentally relevant conditions, in both the laboratory and the field.

Multiresidue extraction of current-use pesticides from complex solid matrices using energized dispersive guided extraction with analysis by gas and liquid chromatography tandem mass spectroscopy

The development of sample processing techniques that recover a broad suite of pesticides from solid matrices, while mitigating coextracted matrix interferences, and reducing processing time is beneficial for high throughput analyses. The objective of this study was to evaluate the effectiveness of an automated extraction system for pesticide analyses in solid environmental samples. An Energized Dispersive Guided Extraction (EDGE) system was used to evaluate two different extraction solvents in optimizing the extraction of 210 pesticides and pesticide transformation products. A graphitized carbon cleanup step was implemented, and three elution solvents were evaluated separately for analyte recoveries. Recoveries between 70 and 130% were achieved for 167 compounds in a test soil using acetonitrile as an extraction solvent and carbon cleanup with acetonitrile and dichloromethane elutions. Nine field samples (soil, sediment, and biosolids) were extracted using the newly developed method and were compared with a previously validated pressurized liquid extraction (PLE) method using an Accelerated Solvent Extraction (ASE) system. Concentrations obtained from the two methods were comparable (linear R2 > 0.999), suggesting similar performance between the EDGE and PLE extractions in complex matrices. The new method provided slightly better sensitivities in comparison to the PLE method, ranging from 0.09 to 2.56 ng g−1. The method presented here significantly reduces extraction setup and runtimes while also minimizing the volume of carcinogenic solvents (e.g., dichloromethane) used in the laboratory and presents a sensitive multiresidue method for a wide range of pesticides in solid matrices.

Online Extraction Followed by LC-MS/MS Analysis of Lipids in Natural Samples: A Proof-of-Concept Profiling Lecithin in Seeds.

Sample preparation is usually a complex and time-consuming procedure, which can directly affect the quality of the analysis. Recent efforts have been made to establish analytical methods involving minimal sample preparation, automatized and performed online with the analytical techniques. Online Extraction coupled with Liquid Chromatography-Mass Spectrometry (OLE-LC-MS) allows a fully connected extraction, separation, and analysis system. In this work, the lecithin profile was investigated in commercial sunflower, almonds, peanuts, and pistachio seeds to demonstrate that the concept of extraction, followed by the online analysis of the extract, could be applied to analyze this class of analytes in such complex solid matrices without a prior off-line solvent extraction step. The extraction phase gradient method was optimized. Two different analytical columns were explored, one being a conventional C18 (50 × 2.1 mm, 1.7 µm SPP) and the other a novel self-packed SIGO-C18ec (100 × 0.5, 5 µm FPP), which resulted in better separation. The analysis repeatability was investigated, and suggestions to improve it were pointed out. A characteristic ion with a m/z of 184, related to lysophosphatidylcholine structure, was used to identify the lecithin compounds. The temperature effect on the chromatograms was also explored. In short, it was found that the OLE-LC-MS approach is suitable for the analysis of lecithin compounds in seeds, being a promising alternative for lipidomics approaches in the near future.

Quantifying the occurrence of polystyrene nanoplastics in environmental solid matrices via pyrolysis-gas chromatography/mass spectrometry

Although polystyrene (PS) is one of the most abundant plastic particles and PS nanoplastics (PS-NPs) have been found in water phase and aquatic organisms, their occurrence in natural solid matrices is rarely reported due to the lack of methods. Herein, on the basis of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique, for the first time a simple and robust protocol was developed for the extraction of PS-NPs to investigate their presence in environmental solid samples. Parameters of the extraction procedures, including extractant compositions and concentrations, shaking time, extractant to solid ratio, and pH were investigated with palladium-doped PS-NPs. Then, the optimized procedures were validated to extract and quantify commercial PS-NPs with different sizes spiked in complex solid matrices. Detection limit of 0.02 µg/g was obtained, and recoveries were 72.5–87.2 % for PS-NPs spiked in environmental solid matrices at levels of 21.6 µg/g. The method was successfully used for the determination of the indigenous PS-NPs ranging from 0.16 to 0.73 µg/g in six out of 11 natural solid samples, confirming the previous speculation that environmental solid matrices are important sources and sinks of NPs. Consequently, this study paves new avenue for closely monitoring NPs in environmental solid matrices and evaluating their potential risks.

Repeatable separation of microplastics integrating mineral oil extraction and a PDMS-Ni foam adsorbent in real soil

The accumulation of microplastics (MPs) in the environment has accelerated. It is very challenging to separate MPs from complicated solid substrate matrices such as soil and sediments not only because solid substrates usually adhere to or surround MPs but also because there is no standardized method for extracting MPs. Here, we report a novel adsorption-based repeatable process for separating and efficiently recovering MPs from environmental matrices using mineral oil and a polydimethylsiloxane (PDMS)-coated nickel (Ni) foam adsorbent. The hydrophobic/magnetic adsorbent was produced by chemical vapor deposition of PDMS on Ni foam. This process created a hydrophobic surface throughout three-dimensional (3D) porous Ni network, providing high porosity, high surface area, and robustness. Compared to tested vegetable oils, mineral oil was superior at extracting seven types of MPs (LDPE, PP, PS, PC, PET, PVC, and PTFE) with different densities of 0.94 ∼ 2.2 g/cm3 from real soil samples. After the mineral oil extraction, by stamping the PDMS-Ni foam on the floating oil layer of the extracted materials, oil-captured MPs of various types and sizes (70 ∼ 1200 μm) were successfully recovered and identified in seconds without accompanying unwanted particles. In addition, due to the reusability of the PDMS-Ni foam, the MPs were isolated several times simply by supplementing the sample with mineral oil, and this procedure results in over 99% of MPs becoming isolated from complex solid matrices. Thus, our adsorption-based repeatable process for separating MPs can allow for an accurate quantitative analysis of microplastic accumulation in solid matrices.

Identification and Speciation of Nanoscale Silver in Complex Solid Matrices by Sequential Extraction Coupled with Inductively Coupled Plasma Optical Emission Spectrometry.

Nanoscale silver (n-Ag) including silver nanoparticles (Ag-NPs), silver chloride nanoparticles (AgCl-NPs), and silver sulfide nanoparticles (Ag2S-NPs) and their corresponding ionic counterpart, namely, dissolved Ag, may coexist in soils. X-ray absorption near edge spectroscopy (XANES) is used to elucidate the speciation of n-Ag in soils, whereas it possesses drawbacks like high costs, rare availability of the instrument, and providing semiquantitative data. We developed a new method for the identification and speciation of n-Ag in soils and sediments based on a sequential extraction technique coupled with inductively coupled plasma optical emission spectrometry. Extraction conditions were first evaluated, establishing the optimal extraction procedure; Ag-NPs, AgCl-NPs, and dissolved Ag in soil were simultaneously extracted by using an aqueous solution of 10 mM tetrasodium pyrophosphate, followed by selective isolation and quantification via AgCl-NPs dissolution (4.45 M aqueous ammonia), centrifugation (Ag-NPs), and detection. The Ag2S-NPs remaining in the soil were then extracted with Na2S solution at pH 7.0 through selective complexation. Optimal recoveries of Ag-NPs, AgCl-NPs, Ag2S-NPs, and dissolved Ag were 99.1 ± 2.4%, 112.0 ± 3.4%, 96.4 ± 4.0%, and 112.2 ± 4.1%, respectively. The method was validated to investigate the speciation of n-Ag in soils and sediments, exhibiting the distribution of Ag-NPs, AgCl-NPs, Ag2S-NPs, and dissolved Ag in each sample, wherein Ag2S-NPs, the major species of n-Ag, accounted for 35.42-68.87% of the total Ag. The results of n-Ag speciation in soil are comparable to those obtained through the linear combination fitting of XANES. This method thus is a powerful, yet convenient, substitute for XANES to understand the speciation of n-Ag in complex solid matrices.

Methods for separating microplastics from complex solid matrices: Comparative analysis

Microplastics (MPs) are widely found in complex solid matrices such as soil, sediments and sludge. The separation procedure is crucial for effective analysis of MPs, but existing methods varied among studies. Here, we systematically summarize and compare separation methods including density, oil, electrostatic, magnetic, and solvent extraction separation. Density separation is the most commonly used approach, but time-consuming and discharging hazardous materials dependent on extraction solutions. In contrast, oil, electrostatic, magnetic separation and solvent extraction separation are emerging approaches with advantages of low-cost, quick, or environmentally-friendly, but with high request of instruments. Despite variation among these approaches, the separation efficiency is closely related to characteristics of MPs including polymer types, sizes and shapes. The treatment of digestion and fluorescence staining can facilitate the detection of MPs. This analysis suggests that further optimization and improvement of existing approaches can facilitate the development of new separation technology for assaying MPs in complex environmental matrices.

A green, simplified, and efficient experimental setup for a high-throughput screening of agri-food by-products – From polar to nonpolar metabolites in sugarcane solid residues

From an environmental perspective, searching for useful compounds in agri-food by-products by employing inefficient and polluting analytical procedures is paradoxical. This work aimed to develop a green, simplified, and highly efficient experimental setup for extracting and tentatively identifying the broadest range of metabolites in sugarcane solid by-products collected directly within the industrial mills. Nine different extraction approaches were investigated side-by-side, including three reference methods. Based on the extraction and environmental performances assessed by two complementary metrics called Analytical-Eco Scale and the Analytical Greenness Calculator, it was possible to reach two highly efficient two liquid-phase extractions while avoiding harmful solvents and traditional time, energy, and solvent consuming sample preparation steps, such as solvent evaporation, metabolite concentration, re-suspension, and derivatization. The simultaneously produced hydroethanolic and n-heptane extracts were directly analyzed by ultra-high-performance liquid chromatography and gas chromatography, both coupled to mass spectrometry, respectively, leading to the annotation of a large dynamic range of compounds from information rich spectral data. Up to 111 metabolites were identified in a single matrix, from highly polar sucrose to nonpolar wax ester C53 in a single extraction. Orientin, apigenin-6-C-glucosylrhamnoside, 1-octacosanol, octacosanal, and other bioactive compounds were identified in these abundantly available by-products, which are currently just burned to produce energy. The best two methods developed here (Two-Liquid-Phase Ultrasound-Assisted Extraction with Probe and Two-Liquid-Phase Dynamic Maceration) appeared as a green, simplified, and highly efficient procedures to qualitatively profile metabolites in complex solid matrices.

Rapid in situ quantitation of photoinitiators in packaging by two-points kinetic calibration of liquid microjunction surface sampling-mass spectrometry

Absolute quantitation is always a challenge for in situ analysis of solid samples with ambient liquid extraction mass spectrometry due to unknown sampling efficiencies of analytes from complex solid matrices such as commercial packaging materials. Standards were usually dropped onto the sample surface for signal calibration, but the mass transfer of standards would not be the same as analytes distributed in samples. In this work, an in situ quantitation method via liquid microjunction sampling (LMJSS) coupled with mass spectrometry (MS) for photoinitiators (PIs) in packaging was developed without standard spiking. For direct in situ quantitation, mass transfer kinetic model for LMJSS of solid surface was proposed and validated. Results showed that the detection data well fitted the mass transfer model with adjusted R2 mostly in the range of 0.8–0.9 for 12 PIs in both lab-made mimetic positive samples and commercial packaging samples. According to the mass transfer kinetic model, two-point kinetic calibration method was proposed for calculation of the absolute concentration of PIs in solid samples by LMJSS of the same sample area for two times. The conditions of LMJSS including extraction solvent composition and solvent flowrate were optimized. With the optimized LMJSS-MS method and new calibration method, in situ analysis was done within only 2 min, and detection limits and quantitation limits of 15 PIs in mimetic samples were in the range of 0.06–1.5 mg/m2 and 0.34–6 mg/m2 respectively with relative standard deviation (RSDs) in the range of 2%–26%. The quantitation accuracy by the new calibration method for 13 PIs was in the range of 61%–162%. The method was applied to the quantitation of PIs in commercial packaging samples. 6 PIs were detected and identified in four commercial packaging materials, and the quantitation results were comparable with that by traditional solvent extraction-LC-MS method (relative recovery, 63%–127%).

A rapid HPLC-FLD method for Ochratoxin A detection in pig muscle, kidney, liver by using enzymatic digestion with MISPE extraction

Ochratoxin A (OTA) is a mycotoxin produced as a secondary metabolite by various Aspergillus and Penicillium species with nephrotoxic, carcinogenic, immunotoxic and teratogenic effects. OTA has been found in several food commodities, including cereals, beer, wine and spices. OTA can also be present in animal products (especially in pig derived products) as a result of carryover from contaminated feed. Permitted level of 1 µg/kg OTA in pig meat or pig-derived products was set in Italy, as in other countries. Key parameters which affected MISPE, should be described such as extraction efficiency and were optimized, analyzed by an isocratic HPLC-FLD method. Under the optimized conditions, for all analyzed matrices mean recovery was > 89%. Method can be applied as alternative routine procedure to detect OTA presence in pig products.Points:*Aim of the study was to develop and validate a quantitative HPLC-FLD method based on MISPE with complex solid matrices (edible tissues) followed by chromatographic analysis.*The new method was developed and validated in pig complex matrix and is very sensitive LOD and LOQ respectively 0.001 and 0.003 µg/kg.*This method is relatively simple to use and with good performances. Was possible to reuse MISPE column with a “regeneration” solution, until to 7 times.

Validation of a Method for Extracting Microplastics from Complex, Organic-Rich, Environmental Matrices.

Complex and organic-rich solid substrates such as sludge and soil have been shown to be contaminated by microplastics; however, methods for extracting plastic particles have not yet been systemically tested or standardized. This study investigated four main protocols for the removal of organic material during analysis of microplastics from complex solid matrices: oxidation using H2O2, Fenton's reagent, and alkaline digestion with NaOH and KOH. Eight common polymer types were used to assess the influence of reagent exposure on particle integrity. Organic matter removal efficiencies were established for test sludge and soil samples. Fenton's reagent was identified as the optimum protocol. All other methods showed signs of particle degradation or resulted in an insufficient reduction in organic matter content. A further validation procedure revealed high microplastic extraction efficiencies for particles with different morphologies. This confirmed the suitability of Fenton's reagent for use in conjunction with density separation for extracting microplastics. This approach affords greater comparability with existing studies that utilize a density-based technique. Recommendations for further method optimization were also identified to improve the recovery of microplastic from complex, organic-rich environmental samples.

A simple method for point-of-need extraction, concentration and rapid multi-mycotoxin immunodetection in feeds using aqueous two-phase systems

The rapid detection of mycotoxins in feed samples is becoming an increasingly relevant challenge for the food production sector, in order to effectively enforce current regulations and assure food and feed safety. To achieve rapid mycotoxin detection, several biosensing strategies have been published, many reaching assay times of the order of a few minutes. However, the vast majority of these rely on sample preparation based on volatile organic solvents, often comprising complex multi-step procedures and devoid of clean-up and/or concentration effects. Here, a novel sample preparation methodology based on a green, non-toxic and inexpensive polyethylene glycol-sodium citrate aqueous two-phase system is reported, providing single-step extraction and concentration of three target mycotoxins within 20min: aflatoxin B1 (AFB1), ochratoxin A (OTA) and deoxynivalenol (DON). With point-of-need applications in mind, the extraction procedure was optimized and validated using a rapid multi-toxin microfluidic competitive immunoassay. The assay was successfully tested with spiked complex solid matrices including corn, soy, chickpea and sunflower-based feeds and limits of detection of 4.6ngg−1±15.8%, 24.1ngg−1±8.1% and 129.7ngg−1±53.1% (±CV) were obtained in corn for AFB1, OTA and DON, respectively. These sensitivities are fit-for-purpose at the required regulatory and recommended limits for animal feed, providing an effective and safe semi-quantitative mycotoxin analysis that can be performed in the field.

Cooling/heating-assisted headspace solid-phase microextraction of polycyclic aromatic hydrocarbons from contaminated soils

A simple, low-cost, and effective cooling/heating-assisted headspace solid-phase microextraction (CHA–HS–SPME) device, capable of direct cooling the fiber to low temperatures and simultaneous heating the sample matrix to high temperatures, was fabricated and evaluated. It was able to cool down the commercial and handmade fibers for the effective tapping of volatile and semi-volatile species in the headspace of complex solid matrices, with minimal manipulation compared with conventional SPME. The CHA–HS–SPME system can create large temperature gaps (up to 200 °C) between the fiber and the sample matrix, because the cooling process is directly applied onto the fiber.Different effective experimental parameters for the fabrication of the CHA–HS–SPME device as well as for the extraction and determination of polycyclic aromatic hydrocarbons (PAHs) from solid samples were evaluated and optimized. The proposed device coupled to GC-FID was successfully applied for the extraction and determination of PAHs in contaminated soils without any sample pretreatment step. Good agreement was observed between the results obtained by the proposed CHA–HS–SPME-GC-FID method and those achieved by validated method.

Ionic‐liquid‐based dispersive liquid–liquid microextraction for high‐throughput multiple food contaminant screening

This paper describes an innovation of dispersive liquid-liquid microextraction enabling multiple-component analysis of eight high-priority food contaminants in two chemically distinctive families: Sudan dyes and phthalate plasticizers. To provide convenient sample handling for solid and solid-containing matrices, a modified dispersive liquid-liquid microextraction procedure used an extractant precoated frit to perform simultaneous filtration, solvent mixing, and phase dispersion in one simple step. A binary ionic liquid extractant system was carefully tuned to deliver high quality analysis based only on affordable LC with diode array detector instrumentation. The method is comprehensively validated for robust quantification with good precision (6.9-9.8% RSD) in a linear 2-1000 μg/L range. Having accomplished enrichment factors up to 451, the treatment enables sensitive detection at 0.09-1.01 μg/L levels. Analysis of six high-risk solid condiments and sauces further verified its practical applicability within a 70-120% recovery range. Compared to other approaches, the current dispersive liquid-liquid microextraction treatment offers major advantages in terms of minimal solvent (1.5 mL) and sample (0.1 g) consumption, ultra-high analytical throughput (6 min), and the ability to handle complex solid matrices. The idea of performing simultaneous analysis for multiple contaminants presented here fosters a more effective mode of operation in food control routines.

A study of the reductive pyrolysis behaviour of sulphur model compounds

The difficulties inherent in the direct determination of sulphur functionalities in complex solid matrices by various techniques often make the need for reference compounds indispensable. One of the pyrolysis techniques used for sulphur determination is atmospheric pressure–temperature programmed reduction (AP-TPR). Experiments on sulphur model compounds have served successfully as a reference for both the temperature region in which the reduction or hydrogenation occurs and the efficiency of the reduction reaction. In this study, the pyrolysis behaviour of several organic and inorganic sulphur model compounds is investigated by AP-TPR using a mass spectrometer detector interfaced with the pyrolysis reactor (AP-TPR-MS). This technique permits a more complete description of the competitive and successive reactions that are occurring during the pyrolysis of the model compounds, providing new information regarding the reduction efficiency of oxidised and non-oxidised sulphur compounds.

Supercritical fluid extraction of 2,4,6-trichloroanisole from cork stoppers.

2,4,6-Trichloroanisole (TCA) is the compound most often associated with cork taint in wines and has been shown to have a very low sensory threshold ( approximately 5 ng/L in wine). A supercritical fluid extraction (SFE) method for TCA in bark cork stoppers was developed with quantification via gas chromatography-mass spectrometry with selected ion monitoring. Supercritical carbon dioxide functioned as the extracting solvent, and temperature and pressure were optimized for the extraction. The method was validated using the stable isotope (2)H(5)-TCA as the internal standard. Recovery of TCA from spiked corks was found to be within 1-4% of the theoretical concentration with a coefficient of variation ranging from 2.6 to 9.7%. TCA levels in corks pulled from wines described as tainted by experienced judges ranged from 0.13 to 2.11 microg/g of cork. The SFE procedure offers a rapid, quantitative, nearly solvent-free, and automated method for the extraction of TCA from complex solid matrices such as cork.

Stability of chemical species in environmental matrices

The stability of chemical species in environmental samples is a critical factor during storage, owing to the interconversion and degradation processes which can occur in species characterisation. The preservation and stabilisation of these chemical species in the time interval between sampling and analysis is a difficult task and several studies have been developed to improve the quality of this aspect of speciation analysis. The Measurement and Testing Programme (formerly BCR) has undertaken projects focused on a variety of species (e.g. Sn, Se, As, Sb, Hg, Pb, Cr), which have been complemented by the studies of other authors. The procedures proposed are reviewed in detail and the influence of critical operational parameters for species stability, such as pH, temperature, light and the container material is considered. The problems are not yet completely solved, especially for complex solid matrices such as soils, sediments and biological tissues.

Analyte detection in complex solid matrices with pyrolysis—atmospheric pressure chemical ionization tandem mass spectrometry

Convenient protocols as well as a high degree of selectivity in the analysis of solid analytes in complex solid matrices represent desirable experimental characteristics, especially when extraction, filtration and sample clean-up are the norm. Pyrolysis (Py), or the rapid heating of a sample, coupled with the selectivity and straightforward sample introduction conduit of atmospheric pressure chemical ionization interfaced to tandem mass spectrometry (APCI-MSMS) is shown to provide significant benefits in the analytical experimentation scenario. Complex solids are investigated for the presence of a myriad of solid analytes with the PyAPCI-MSMS technique. This technique presents advantages such as a robust screening method for analyte detection and characterization.

Qualitative supercritical fluid extraction coupled to capillary gas chromatography

AbstractThe usefulness and ease of utilizing supercritical fluid extraction (SFE) directly coupled to capillary gas chromatography (GC) as quantitative or qualitative analytical problem‐solving tools will be demonstrated. As an alternative to conventional liquid solvent extractions, SFE presents itself as a means to achieve high extraction efficiencies of different compounds in complex solid matrices in very rapid tims frames. Moreover, SFE has an additional advantage of being able to achieve distinct extraction selectivities as a function of the solubilizing power of the supercritical fluid extracting phase. For on‐line SFE/GC, the extraction effluent is directly transferred to the analytical chromatograph. On‐line SFE/GC involves the decompression of pressurized extraction effluent directly into a heated, unmodified capillary split injection port of the GC. In this respect, SFE introduction into GC can be used as an alternative means of GC injection, comparable to such modes of injection as pyrolysis and thermal desorption. This paper will show applications of SFE/GC where mass spectrometric detection together with flame ionization detection was used for component identification from environmental, tobacco, and petroleum matrices.