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The online coupling technique of sample preparation with chromatography is a frontier topic in analytical chemistry since it minimizes errors caused by sample loss, shortens analysis time, and reduces solvent consumption. An online pressure change focusing-supercritical fluid selective extraction chromatography (PCF-SFSEC) technique was developed in this study, realizing extraction, purification, separation, and detection in a single run with only microliter-scale samples. The pressure change focusing strategy achieved column-head stacking by decreasing the dissolving capacity of the supercritical fluid, enabling the large volume introduction of extractants into supercritical fluid chromatography without causing peak broadening or distortion. All the extracts could be directly loaded into the chromatography system without split flow. Based on the supercritical fluid selective extraction (SFSE) strategy, the sorbents removed interferences and water from samples, effectively alleviating matrix effects and realizing the direct aqueous sample analysis. The efficiency of online PCF-SFSEC was demonstrated by the enantioselective analysis of 22 chiral drugs in rat plasma, covering eight categories with different pharmacological effects. The entire analysis took 25 min, consuming only 5 μL samples. All analytes in PCF-SFSEC obtained sharp and symmetrical peaks with resolutions higher than 1.0, and 86% had resolutions higher than 1.5. Limits of quantification (LOQs) ranged from 0.0600 to 32.1 μg/L. Recoveries were in the range of 75.8-117.2%. In addition, the developed approach obtained more satisfactory repeatability and significantly reduced matrix effects than conventional methods. The newly established online PCF-SFSEC technique is believed to be a green and powerful tool for the chiral analysis of complex samples.

Recent studies strongly suggest that atorvastatin combination therapy with tangeretin could be beneficial in the treatment of hyperlipidemia. This study aimed to investigate the pharmacokinetic interactions among atorvastatin, its active metabolite 2-hydroxy atorvastatin, and tangeretin after oral administration of atorvastatin with tangeretin in rats. A rapid, selective, and sensitive assay was developed and validated based on ultra-high performance supercritical fluid chromatography-tandem mass spectrometry for the simultaneous measurement of atorvastatin, 2-hydroxy atorvastatin, and tangeretin concentrations in rat plasma. Chromatographic separation of the analytes was conducted on an ACQUITY Torus 1-AA column in gradient elution mode. The mass transition ion pairs were m/z 559.0→440.0 for atorvastatin, m/z 575.2→440.0 for 2-hydroxy atorvastatin, m/z 373.0→358.1 for tangeretin, and m/z 254.8→136.7 for daidzein (internal standard). Calibration curves showed good linear correlations at the following concentration range: 1-400 (r = 0.9952), 1-400 (r = 0.9980), and 3-1200 (r = 0.9945) for atorvastatin, 2-hydroxy atorvastatin, and tangeretin, respectively. The method was fully validated and satisfied the acceptance criteria recommended by the United States Food and Drug Administration. Finally, it was successfully applied in a pharmacokinetic study in rats to evaluate the pharmacokinetic behavior of atorvastatin, 2-hydroxy atorvastatin, and tangeretin.

Octadecanoids are broadly defined as oxylipins (

Response surface methodology (RSM) is a widely used mathematical and statistical technique for modeling and optimizing the process for the extraction of bioactive compounds. This review explains the optimization approach through the use of experimental design and empirical models for response prediction and the utilization of the desirability function for multiple response optimization. This paper also reviews recent studies on the application of RSM to optimize bioactive compound extraction processes such as conventional solvent extraction, microwave-assisted extraction, supercritical fluid extraction, and ultrasound-assisted extraction. Finally, the challenges associated with the use of RSM and the efforts made to improve RSM in the extraction process are also highlighted. Overall, this review informs many aspects of RSM that are occasionally ignored or insufficiently discussed with regard to the optimization of bioactive compound extraction processes, and it summarizes significant applications where RSM proved suitable. © 2022 Society of Chemical Industry.

Enantioselective analytical approaches are essential for monitoring pharmacokinetics and acquiring accurate data to better understand the role of stereochemistry in pharmacokinetics. Enantioselectivity significantly impacts the pharmacokinetics of chiral drugs, especially in metabolic profile, leading to toxicity of enantiomer. Consequently, there is a need to study the pharmacokinetics of enantiomerically pure drugs and racemates as they differ in affinity with enzymes and proteins. Combining the best enantioseparation conditions with the specified biological matrix and the intended purpose of the analysis is a challenging task. This review discusses the importance of chirality in stereoselective pharmacokinetics with more relevant examples, various enantioselective analytical techniques, and stationary phases employed. Challenges such as lack of universal chiral columns, biological inversion of the isomers, and others have been discussed. Further presented the recent advances in the screening of chiral drugs and innovative improvements in the analytical approaches for chiral molecule analysis such as supercritical fluid chromatography, simulated moving bed chromatography, and other techniques are discussed.

The application area of supercritical fluid chromatography expanded tremendously over the last years and more polar analytes such as biomolecules have become accessible. The growing interest in biopharmaceuticals and associated regulatory requirements demand alternative analytical tools. The orthogonal nature of supercritical fluid chromatography compared to reversed-phase liquid chromatography meets these needs and makes it a useful option during research and development. In this study, we present a systematic approach for the development of a supercritical fluid chromatography method for fingerprinting of tyrothricin, a complex therapeutic peptide covering a mass range from 1200 to 1900 Da. The substance was chosen due to the presence of cyclic and linear peptides and isomeric or highly similar amino acid sequences. Different column chemistries covering neutral, basic, and zwitterionic functionalities in combination with acidic, basic, and neutral additives were screened. Subsequently, Design-of-Experiments principles were utilized to perform optimization of the chromatographic parameters. The final mass spectrometry-compatible gradient method using a diol stationary phase, carbon dioxide, and a modifier consisting of methanol/water/methanesulfonic acid (100:2:0.1, v:v:v) was found to provide orthogonality and superior resolution to other methods published. Isomeric peptide compounds coeluting in reversed-phase liquid chromatography were resolved by applying the final method.

In this study, an analytical method has been developed that, for the first time, allows simultaneous determination of vitamin D

Supercritical fluid chromatography and high-performance liquid chromatography techniques are popular for the chiral separations of different drugs and pharmaceuticals. Therefore, this article describes a comparative study of the chiral separation of some calcium channel antagonists such as verapamil, gallopamil, and nisoldipine. The columns used were Chiralpak IG and Chiralpak ID (250 mm × 4.6 mm, 5.0 μm). The separation was achieved by using a variety of mobile phases in both techniques. The retention, separation, and resolution factors in SFC were in the range of 1.36-7.30, 1.09-1.72, and 1.16-3.47, while these values in the case of HPLC were 1.03-2.42, 1.12-1.35, and 0.49-2.46. The complete resolution of gallopamil and verapamil was achieved successfully. The chiral recognition was controlled by hydrogen bondings, π-π interactions, dipole induced dipole interactions, van der Waal forces, and steric effects. SFC was found to be a better technique than HPLC because of quick separation, good separation power, economic, environment-friendly, and green technology.

The purpose of the current study was to evaluate an analytical characterization of a novel synthetic cannabinoid ethyl-2-(1-(5-fluoropentyl)-1H-indole-3-carboxamido)-3,3-dimethylbutanoate (5F-EDMB-PICA), which has a similar chemical structure to the controlled synthetic cannabinoid 5F-MDMB-PICA. The compound was analyzed by gas chromatography–mass spectrometry (GC–MS), supercritical fluid chromatography–quadrupole time-of-flight-mass spectrometry (SFC–QTOF-MS) and spectroscopic methods, such as attenuated total reflection (ATR)-Fourier transform infrared (FTIR), ultraviolet-visible (UV-VIS) and nuclear magnetic resonance (NMR) spectroscopies. In this study, we reported a comprehensive analytical data of 5F-EDMB-PICA. The data of analytical characterization for the 5F-EDMB-PICA were obtained by GC–MS, SFC–QTOF-MS, ATR-FTIR spectroscopy, UV-VIS spectroscopy, and 1H and 13C NMR spectroscopy. In this study, we presented a comprehensive analytical characterization of 5F-EDMB-PICA obtained by 1H NMR, 13C NMR, GC–MS, SFC–QTOF-MS, ATR-FTIR spectroscopy and UV–VIS spectroscopy. The analytical data of 5F-EDMB-PICA are very useful for forensic, toxicological, and clinical diagnosis.

In this paper, we review the growing development and applications of supercritical fluid chromatography-mass spectrometry (SFC-MS) for the analysis of small molecular analytes and biomarkers in drug discovery. As an alternative chromatographic technique, SFC instrumentation and methodology have dramatically advanced over the last decade. Mass spectrometry (MS) provides the powerful detection capability as it couples with SFC. A growing number of SFC-MS/MS applications were reported over the last decade and the application areas of SFC-MS/MS is rapidly expanding. The first part of this review is devoted to the different aspects of SFC-MS development and recent technological advancements. In the second part of this review, we highlight the recent application areas in pharmaceutical research and development.

The coupling of columns in sub/supercritical fluid chromatography presents a great opportunity for influencing the separation efficiency and extending the selectivity of the separation system. Combinations of different types of chiral stationary phases could positively affect the enantioresolution if single ones are complementary to each other. In this work, two superficially porous particle (2.7 μm) macrocyclic glycopeptide-based columns, namely TeicoShell and NicoShell, were serially coupled and tested in sub/supercritical fluid chromatography for the first time. The influence of the column arrangement on the enantioseparation of structurally diverse biologically active compounds was examined. The obtained results showed how the column order crucially affected the enantioresolution of compounds tested, but the retention was negligibly affected in most cases. We also demonstrated that single TeicoShell and NicoShell columns are very promising towards the development of highly efficient and fast/ultrafast sub/supercritical fluid chromatography methods for structurally different chiral compounds. The optimized methods for sub-minute enantioselective separation of certain biologically important compounds were proposed.

Supercritical fluid extraction is a powerful analytical tool and it is willingly used by researchers for the isolation of various components from different matrices. In our study, the carbon dioxide in the supercritical state was used for the extraction of oils from blackcurrant and black cumin seeds. To determine the optimal conditions for the process (temperature, pressure and time), the method of statistical experiment planning and the Box–Behnken design was applied and the yield of the oils and the content of fatty acids (FAs) were taken into consideration. It has been found that an increase in pressure causes an increase in extraction yield (W), and an increase in temperature, both at constant pressure and time, does not significantly change the yield value. Optimal yield values were obtained for both materials under almost similar extraction parameters: 306 bar/ 43 min/ 50 °C (blackcurrant) and 282 bar/ 40 min/ 50 °C (black cumin). The influence of the above parameters (T, p, t) on the content of FAs in the extracts has a slightly different trend. The use of supercritical carbon dioxide for the extraction of blackcurrant and black cumin seeds allowed for high process yield and high-quality, rich in polyunsaturated fatty acids oils which can be used as a substrate or final product for industry.

Activated carbons are used in industrial applications; their cost is a major barrier to their more widespread application. Regeneration of activated carbons is indispensable to minimize operational costs and product wastage. Supercritical carbon dioxide (SC-CO2) as green technology was used to regenerate activated carbons. In this work, response surface methodology was employed to optimize the supercritical regeneration process and to evaluate the effect of the operational parameters including pressure (100–300 bar), temperature (313–333 K), flow rate (2–6 g/min), and dynamic time (30–150 min) on the regeneration yield. The maximum regeneration yield (93.71%) was achieved at 285 bar, 333 K, 4 g/min, and 147 min. Mathematical modeling was done using two one-parameter kinetics models, which agree well with the experimental data. The fitting parameter of the model was obtained by using a differential evolution algorithm. The chemical composition of the substances extracted from the activated carbon was identified by gas chromatography. The results showed that the regeneration of activated carbon by SC-CO2 can be an alternative method to conventional methods.

The glycoform of a therapeutic monoclonal antibody (mAb) has a significant impact on its effector function as well as its safety and pharmacokinetics. Glycoform heterogeneity is influenced by various factors, including the producing cells and cell culture processes. Therefore, accurate glycoform characterization is essential for drug design, process optimization, manufacturing, and quality control of therapeutic mAbs. In this study, we developed a fast, quantitative, and highly sensitive analytical platform for glycan profiling by supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) and applied the technique to the glycan structural analysis of mAbs. To achieve both the highest sensitivity and the most comprehensive glycan profiling, we integrated our energy-resolved oxonium ion monitoring (Erexim) method with SFC-MS to construct a new SFC-Erexim technology. An 8 min analysis of bevacizumab, nivolumab, ramucirumab, rituximab, and trastuzumab by SFC-Erexim detected a total of 102 glycoforms, with a detection limit of 5 attomoles. The dynamic range of glycan abundance was over 6 orders of magnitude for bevacizumab analysis by SFC-Erexim compared to 3 orders of magnitude for conventional fluorescence HPLC analysis. This method revealed the glycan profile characteristics and lot-to-lot heterogeneity of various therapeutic mAbs. We were also able to detect a series of structural variations in pharmacologically important glycan structures. The SFC-MS-based glycoform profiling method will provide an ideal platform for the in-depth analysis of precise glycan structure and abundance.

The improvement of supercritical fluid chromatography (SFC) instrumentation enhanced its reliability and utility over the past decade. The further development of high speed and high resolution separations is however obstructed by the lack of accurate models for axial dispersion in SFC. This work is a first step to tackle this by developing more reliable methods to measure molecular (Dmol) and longitudinal diffusion (Deff) in SFC, as these affect all aspects of separation efficiency. In the present contribution, we report on an improved method, to enable more flexible, reliable and accurate measurements of Dmol in SFC using commercial instrumentation. A two-column variant of the stopped-flow experiment is proposed as an adapted set-up for measuring the effective longitudinal diffusion coefficient Deff in SFC-conditions. Using the set-ups for a number of test-compounds, it has been found that Deff, and the coefficients describing its constituent sub-processes (cf. particle diffusion Dpart and surface diffusion γsDs), all vary in a linearly proportional way with the bulk diffusion coefficient Dmol within a high degree of accuracy. It has also been found that Deff decreases much more sharply with increasing retention factor compared to LC. By applying the effective medium theory, it was found that the relative surface diffusion coefficient γsDs/Dmol decreases strongly with retention factor for the investigated solutes and column, in contrary to what is typically observed in reversed phase liquid chromatography. Results indicate that this might be related to a change in retention behavior of the analytes. Obviously, more analytes and conditions need to be explored to complete this picture and the extend range of applicability of these observations.

The employment of supercritical carbon dioxide extraction for obtaining the chemical compounds from

The chromatographic analysis of long-chain hydrophilic therapeutic peptides, with molecular weight mostly in the 3500-4500 Da range (31-34 amino acids), is explored with pressurized CO

Phthalic acid esters are widely used as components of industrial and consumer products including paper and cardboard packaging materials in contact with food or human skin. Being endocrine-disrupting chemicals, phthalic acid esters have a negative effect on human health and must be controlled in pulp and paper products. In the present study, supercritical fluid chromatography-tandem mass spectrometry in combination with pressurized liquid extraction was proposed for phthalic acid esters determination in such objects. Octadecyl stationary phase with non-endcapped silanol groups ensured rapid (4 min) separation of the 10 priority phthalic acid esters in isocratic elution mode and allowed for effective elimination of interferences from the trace impurities of phthalic acid esters in the mobile phase. The attained limits of quantitation are in the range of 0.7-10 μg/L in extracts and 0.02-0.3 μg/g in paper and cardboard samples. The developed method is distinguished by analysis rapidity, easy sample preparation procedure, high selectivity, low susceptibility to mobile phase contamination with analytes, low cost, and environmental friendliness due to the use of carbon dioxide as a main component of the mobile phase. The method was successfully tested on real samples of toilet paper and food packaging paper and cardboard in which eight analytes were found at the levels of 0.03-43.5 μg/g.

Background Resveratrol and emodin are abundant polyhydroxy compounds that are found in the Chinese traditional medicinal herb Polygonum cuspidatum and widely used due to their excellent antioxidant properties. Objective This study aimed to obtain the maximum extraction yields of resveratrol and emodin from P. cuspidatum via green extraction. Methods The extracts were acquired through supercritical carbon dioxide (SC-CO2) extraction with ethanol as cosolvent. The independent variables of the extraction process, namely temperature (45–55°C), pressure (20–30 MPa), and ethanol content (80–120 mL/L), were optimized by response surface methodology. Results These variables had marked effects on the yields of resveratrol and emodin. Second-order polynomial mathematical models were developed and applied to predict the optimal extraction conditions (i.e., temperature of 51.8°C, pressure of 25.34 MPa, and ethanol content of 110.83 mL/L). Under these conditions, confirmatory experiments showed that the yields of resveratrol and emodin were 2.564 ± 0.121 and 2.804 ± 0.108 mg/g, respectively. High antioxidant properties, strong free radical scavenging abilities, and good reducing abilities were observed for the extracts. Conclusion Resveratrol and emodin can be successfully extracted from P. cuspidatum by SC-CO2, and RSM can optimize the process. Highlights The SC-CO2 extraction of resveratrol and emodin from P. cuspidatum was developed, and RSM was successfully used to optimize the extraction parameters and predict the optimal conditions.

Saliva is an attractive sampling matrix for measuring various endogenous and exogeneous substances but requires sample treatment prior to chromatographic analysis. Exploiting supercritical CO2 for both extraction and chromatography simplifies sample preparation, reduces organic solvent consumption, and minimizes exposure to potentially infectious samples, but has not yet been applied to oral fluid. Here, we demonstrate the feasibility and benefits of online supercritical fluid extraction coupled to supercritical fluid chromatography and single-quadrupole mass spectrometry for monitoring the model salivary tracer caffeine. A comparison of 13 C- and 32 S-labeled internal standards with external standard calibration confirmed the superiority of stable isotope-labeled caffeine over nonanalogous internal standards. As proof of concept, the validated method was applied to saliva from a magnetic resonance imaging study of gastric emptying. After administration of 35 mg caffeine via ice capsule, salivary levels correlated with magnetic resonance imaging data, corroborating caffeine's usefulness as tracer of gastric emptying (R2 = 0.945). In contrast to off-line methods, online quantification required only minute amounts of organic solvents and a single manual operation prior to online bioanalysis of saliva, thus demonstrating the usefulness of CO2 -based extraction and separation techniques for potentially infective biomatrices.

Graphical abstract Abundant studies have been published evaluating different parameters of reverse-phase liquid chromatography (LC) and supercritical fluid chromatography (SFC), both coupled to electrospray (ESI)/mass spectrometry (MS) for pesticide residue analysis. However, there is a lack of a comprehensive comparative study that facilitates deep knowledge about the benefits of using each technique. In the present study, the same mass spectrometer was used coupled to both liquid and supercritical fluid chromatographies with a multiresidue method of 215 compounds, for the analysis of pesticide residues in food samples. Through the injection of the spiked extracts, separate experiments were conducted. A study of the optimum ion source temperature using the different chromatography modes was performed. The results were evaluated in terms of sensitivity with tomato, leek, onion, and orange as representative fruit and vegetable matrices. The compounds which reported the highest area values in each chromatography were evaluated through their substance groups and polarity values. The impact of matrix effects obtained in tomato matrix was similar for both cases; however, SFC clearly showed better results in analyzing matrices with a higher number of natural co-extracted compounds. This can be explained by the combination of two effects: (i) chromatography separation and (ii) ion source efficiency. The chromatographic elution presented different profiles of matrix components, which had diverse impact on the coelution with the analytes, being more beneficial when SFC was used in the matrices studied. The data showed that the best results obtained in SFC are also related to a higher ionization efficiency even when the ESI emitter tip was not optimized for SFC flow. In the present study a comprehensive evaluation of the benefits and drawbacks of these chromatography modes for routine pesticide residue analysis related to target compounds/commodities is provided. Supplementary Information The online version contains supplementary material available at 10.1007/s00216-021-03565-4.

A fast and simple ultra-high performance supercritical fluid chromatography method has been developed for the determination of six analytes, namely (paeonol, coumarin, cinnamic alcohol, cinnamic acid, paeoniflorin and amygdalin) in Guizhi Fuling capsule and tablet samples. The influence of the key chromatographic parameters for the separation purposes was evaluated. The optimal column was Trefoil CEL1 column. The optimal mobile phase was a gradient mixture of carbon dioxide and methanol at flow rate of 1.0 mL min-1 . The back pressure of the system was set to 1.38×107 Pa and the temperature to 45 ℃. The six compounds were separated within 11 min by the proposed ultra-high performance supercritical fluid chromatography method with satisfactory resolution. Method validation confirmed that the procedure is accurate with the recovery rates from 87.04% to 104.30%, intra-day precision values less than less than 4.81% and inter-day precision less than 5.22%, and linear with R2 higher than 0.9967. Therefore, this work provides a simple and novel method for the simultaneous analysis of six compounds in Guizhi Fuling capsule and tablet samples. This article is protected by copyright. All rights reserved.

Aim: Quantification of stereoisomers in biological matrices is of pivotal importance for drug development. Supercritical fluid chromatography paired with chiral stationary phases is the gold standard for resolution of enantiomers. However, this technique often proves inadequate for resolution of polar stereoisomers. Materials & methods: A combination of achiral chemical derivatization with supercritical fluid chromatography using chiral stationary columns to improve enantiomeric resolution is described. Results: Separation of four possible stereoisomers of linerixibat was achieved after derivatization with 3N HCl in n-butanol within 12 min (case1). Derivatization with acetic, propionic, butyric, isobutyric, valeric and isovaleric anhydrides significantly improved the separation of stereoisomers (case 2 and 3) within 10 min. The best stereoisomeric resolution was achieved using valeric and isovaleric anhydrides.

This study tried to quantitatively clarify the usefulness of supercritical fluid extraction for removal of chlorophyll and pheophorbide from Chlorella pyrenoidosa. C. pyrenoidosa powder was subjected to supercritical fluid extraction, and chlorophyll a and pheophorbide a in its extracted fractions were measured by HPLC-UV. Chlorophyll a and pheophorbide a in residue after supercritical fluid extraction became below of detection limit.

In this study, an underutilized citrus family fruit named grapefruit was explored for the extraction of lycopene using supercritical carbon dioxide (CO2) extraction technique. An experimental design was developed using response surface methodology to investigate the effect of supercritical carbon dioxide (CO2) operating parameter viz., pressure, temperature, CO2 flow rate, and extraction time on the extraction yield of lycopene yield from grapefruit. A total of 30 sets of experiments were conducted with six central points. The statistical model indicated that extraction pressure and extraction time individually, and their interaction, significantly affected the lycopene yield. The central composite design showed that the polynomial regression models developed were in agreement with the experimental results, with R2 of 0.9885. The optimum conditions for extraction of lycopene from grapefruit were 305 bar pressure, 35 g/min CO2 flow rate, 135 min of extraction time, and 70 °C temperature.

Proton-transfer-reaction (PTR) mass spectrometry (MS) is capable of detecting trace-level volatile organic compounds (VOCs) in gaseous samples in real time. Therefore, PTR-MS has become a popular method in many different study areas. Most of the currently reported PTR-MS applications are designed to determine volatile compounds. However, the method might be applicable for nonvolatile organic compound detection. Supercritical fluid chromatography (SFC) has been studied in the last 5 decades. This approach has high separation efficiency and predictable retention behavior, making separation optimization easy. Atmospheric ionization techniques, such as atmospheric chemical ionization (APCI) and electrospray ionization (ESI), are the most studied SFC-MS interfaces. These processes require the addition of makeup solvents to prevent precipitation or crystallization of the solute while depressurizing the mobile phase. In contrast, the PTR process is carried out in a vacuum; supercritical carbon dioxide may release solute into the PTR flow tube without a phase transition as long as it is maintained above a critical temperature. Therefore, this might constitute yet another use for the SFC-MS interface. Caffeine and a few other nonpolar compounds in supercritical carbon dioxide were successfully detected with time-of-flight MS without adding solvent by using preliminarily assembled supercritical flow injection and supercritical fluid extraction (SFE)-PTR interfaces.

The global trade of tropical fruits is expected to increase significantly in the coming years. In 2018, the production was approximately 100 million tones, an increase of 3.3% compared to the previous year. Nevertheless, according to the Food and Agricultural Organization, every year one-third of the food produced in the world for human consumption is lost or wasted. More specifically, around 45% of the fruits, constituted mainly by peels, seeds, and pulps after juice extraction, are discarded mainly in the agricultural and processing steps. Therefore, decreasing and/or using these byproducts, which are often rich in bioactive components, have become an important focus for both the scientific community and the fruit processing industry. In this line, supercritical fluid extraction (SFE) technology is expected to play a significant role in the valorization of these byproducts. This review presents the concepts of a tropical fruit biorefinery using supercritical CO2 extraction and the potential applications of the isolated fractions. There is a specific focus on the extraction of bioactive compounds, that is, carotenoids and phenolics, but also oils and other valuable molecules. Moreover, the techno-economic and environmental performance is assessed. Overall, the biorefinery of tropical fruits via SFE provides new opportunities for development of food and pharmaceutical products with improved economic and environmental performance.

The intensive application of pesticides to increase crop production has resulted in contamination of the agricultural products. Due to their occurrence at trace levels and the complexity of food samples, analysis of pesticide residues requires selective and efficient sample preparation methods. For this purpose, an extraction method based on supercritical carbon dioxide and acetonitrile as entrainer solvent was developed for trace analysis of atrazine, diazinon, chlorothalonil, and deltamethrin pesticides in honey samples. A Box-Behnken experimental design was applied to optimize extraction variables including static extraction time (5-15 min), pressure (200-700 bar), and temperature (45-70°C). The optimum extraction conditions were found to be 11.5 min static extraction time, 252 bar, and 70°C. The proposed analytical method showed a good linearity (≥0.998), low limit of detection (0.005-0.009 mg/kg), and good extraction recovery (74-111%). The precision study of the proposed method at two concentration levels of each pesticides, 0.25 and 1.0 mg/kg was found to be in the ranges of 2.3-4.21% for intraday (n = 3) and 3.93-8.02% for interday precisions (n = 3). The developed method is promising for use in trace analysis of pesticides in complex food samples including honey.

Triacylglycerol (TAG) components in human milk during different lactation periods, infant formulas with different fat sources, other mammalian milk (cow, goat, donkey, and yak milk), and plant oil (sunflower, rapeseed, corn, soybean, palm, palm kernel, and coconut oil) were analyzed and compared using ultraperformance supercritical fluid chromatography and quadrupole time-of-flight mass spectrometry (UPSFC-Q-TOF-MS). We identified 191 TAGs (86, 102, 101, and 54 TAGs in human milk, infant formula, mammalian milk, and plant oil, respectively). TAGs esterified with palmitic acid (16:0) were major TAG structures in human milk (59.08% of total TAGs) and contained 30 TAG types. The sn-O/P/O regioisomer constituted more than 80% of the O/P/O content of human milk, whereas the sn-O/O/P levels were higher in other samples. The carbon number (CN) 52 content was higher than the CN 54 content in human milk, with the opposite observed in infant formula. TAGs with CN < 40 content were abundant in cow, goat, and yak milk; donkey milk was rich in CN 52 content. TAGs composed of medium-chain fatty acids (MCFAs) and long-chain fatty acids (LCFAs) were rich in human milk, while TAGs with three MCFAs were rich in infant formula. The TAG characteristics of infant formula were directly related to its fat resource. TAGs with fewer double bonds were abundant in the plant oil formula; however, highly unsaturated TAGs were prominent in the cow and goat milk formulas, similar to plant oil and mammalian milk. Significant differences in the TAG distribution were observed among the different species.

In this study, a rapid and highly efficient method was developed for the separation of eight isoquinoline alkaloids using supercritical fluid chromatography. The separation conditions were carefully optimized including stationary phases, additives, backpressure, and temperature. Compared to high-performance liquid chromatography, the use of supercritical fluid chromatography could provide a 13 times faster separation. Subsequently, the method was validated and applied for the determination of eight alkaloids from different parts of Mahonia bealei (Fort.) Carr. (stem, root, leaf, and seed). The results indicated a good repeatability with relative standard deviations for overall precisions lower than 3.2%. The limit of detection was between 0.4 and 2.3 μg/mL while limit of quantitation ranged from 1.5 to 7.5 μg/mL. Recovery ranged from 95.7 to 102.5% indicating a validity of recovery. The content of total eight alkaloids was the highest in stem (66.0 μg/g) and root (65.1 μg/g) compared to leaf or seed. Moreover, anti-acetylcholinesterase activity for those extracts was evaluated by Ellman's colorimetric assay. As a result, the acetylcholinesterase inhibitory activity of the extracted samples was in the following decreasing order: stem > root > leaf or seed. In conclusion, the results indicated that supercritical fluid chromatography could be a useful tool for quality control of Mahonia bealei (Fort.) Carr. containing alkaloids as active compounds.

This article covers current methods and applications in chiral analysis from 2010 to 2020 for biosamples in clinical research and forensic toxicology. Sample preparation for aqueous and solid biological samples prior to instrumental analysis were discussed in the article. GC, HPLC, capillary electrophoresis and sub/supercritical fluid chromatography provide the efficient tools for chiral drug analysis coupled to fluorescence, UV and MS detectors. The application of chiral analysis is discussed in the article, which involves differentiation between clinical use and drug abuse, pharmacokinetic studies, pharmacology/toxicology evaluations and chiral inversion. Typical chiral analytes, including amphetamines and their analogs, anesthetics, psychotropic drugs, β-blockers and some other chiral compounds, are also reviewed.

Isolation and chemical characterization of target components in fast-paced pharmaceutical laboratories can often be challenging, especially when dealing with mixtures of closely related, possibly unstable species. Traditionally, this process involves intense labor and manual intervention including chromatographic method development and optimization, fraction collection, and drying processes prior to NMR analyses for unambiguous structure elucidation. To circumvent these challenges, a foundational framework for the proper utilization of supercritical carbon dioxide (scCO

Diffusion data are essential for adequate analysis of the kinetic separation performance of any chromatographic system. Unfortunately, for Supercritical Fluid Chromatography (SFC), very little data is available of the diffusion coefficients in mobile phases typically used in contemporary methods, i.e. with a non-negligible amount of polar modifier such as methanol. In this work, a relative simple method which only requires minor modifications to a standard commercially available SFC instrument is used to determine the diffusion coefficient of an extensive set of pharmaceutical compounds in the range of 10–50 vol% of modifier (methanol) in CO2. By using a traditional SFC column, the solute is first separated from the sample solvent plug, before entering a long capillary, where the band broadening can be linked to its diffusion coefficient using the Taylor-Aris equation. By using two UV-detectors, before and after the capillary, the effect of the dispersion in the column can be eliminated and the true volumetric flow rate determined. It was found that in the investigated range of conditions, the change in mobile phase viscosity in a first approximation allows to predict the variation in diffusion coefficient. Chemical structure and more particularly functional groups can however have a significant effect on the diffusion coefficient.

Green bioanalytical techniques aim to reduce or eliminate the hazardous waste produced by bioanalytical technologies. A well-organized and practical approach towards bioanalytical method development has an enormous contribution to the green analysis. The selection of the appropriate sample extraction process, organic mobile phase components and separation technique makes the bioanalytical method green. UHPLC-MS is the best option, whereas supercritical fluid chromatography is one of the most effective green bioanalytical procedures. Nevertheless, there remains excellent scope for further research on green bioanalytical methods. This review details the various sample preparation techniques that follow green analytical chemistry principles. Furthermore, it presents green solvents as a replacement for conventional organic solvents and highlights the strategies to convert modern analytical techniques to green methods.