High-performance Liquid Chromatography Detection Research Articles

Fabrication of sea urchin shaped polyaniline-modified magnetic microporous organic network for efficient extraction of non-steroidal anti-inflammatory drugs from animal-derived food samples

In this work, a novel polyaniline-modified magnetic microporous organic network (MMON-PANI) composite was fabricated for effective magnetic solid phase extraction (MSPE) of five typical nonsteroidal anti-inflammatory drugs (NSAIDs) from animal-derived food samples before high performance liquid chromatography (HPLC) detection. The core-shell sea urchin shaped MMON-PANI integrates the merits of Fe3O4, MON, and PANI, exhibiting large specific surface area, rapid magnetic responsiveness, good stability, and multiple binding sites to NSAIDs. Convenient and effective extraction of trace NSAIDs from chicken, beef and pork samples is realized on MMON-PANI via the synergetic π-π, hydrogen bonding, hydrophobic, and electrostatic interactions. Under optimal conditions, the MMON-PANI-MSPE-HPLC-UV method exhibits wide linear ranges (0.2–1000 μg L−1), low limits of detection (0.07–1.7 μg L−1), good precisions (intraday and inter-day RSDs < 5.4 %, n = 3), large enrichment factors (98.6–99.9), and less adsorbent consumption (3 mg). The extraction mechanism and selectivity of MMON-PANI are also evaluated in detail. This work proves the incorporation of PANI onto MMON is an efficient way to promote NSAIDs enrichment and provides a new strategy to synthesize multifunctional MON-based composites in sample pretreatment.

Fabrication of sea urchin shaped polyaniline-modified magnetic microporous organic network for efficient extraction of non-steroidal anti-inflammatory drugs from animal-derived food samples

In this work, a novel polyaniline-modified magnetic microporous organic network (MMON-PANI) composite was fabricated for effective magnetic solid phase extraction (MSPE) of five typical nonsteroidal anti-inflammatory drugs (NSAIDs) from animal-derived food samples before high performance liquid chromatography (HPLC) detection. The core-shell sea urchin shaped MMON-PANI integrates the merits of Fe3O4, MON, and PANI, exhibiting large specific surface area, rapid magnetic responsiveness, good stability, and multiple binding sites to NSAIDs. Convenient and effective extraction of trace NSAIDs from chicken, beef and pork samples is realized on MMON-PANI via the synergetic π-π, hydrogen bonding, hydrophobic, and electrostatic interactions. Under optimal conditions, the MMON-PANI-MSPE-HPLC-UV method exhibits wide linear ranges (0.2–1000 μg L−1), low limits of detection (0.07–1.7 μg L−1), good precisions (intraday and inter-day RSDs < 5.4 %, n = 3), large enrichment factors (98.6–99.9), and less adsorbent consumption (3 mg). The extraction mechanism and selectivity of MMON-PANI are also evaluated in detail. This work proves the incorporation of PANI onto MMON is an efficient way to promote NSAIDs enrichment and provides a new strategy to synthesize multifunctional MON-based composites in sample pretreatment.

CdTe@ZnS quantum dots for rapid detection of organophosphorus pesticide in agricultural products

Organophosphorus pesticides (OPPs) constitute the most widely employed class of pesticides. However, the prevalent use of OPPs, while advantageous, raises concerns due to their toxicity, posing serious threats to food safety. Chemical sensors utilizing quantum dots (QDs) demonstrate promising applications in rapidly detecting OPPs residues, thereby facilitating efficient inspection of agricultural products. In this study, we employ an aqueous synthesis approach to prepare low toxic CdTe@ZnS QDs with stable fluorescence properties. To mitigate the risk of imprecise measurements stemming from the inherent susceptibility of fluorescence to quenching, we have adopted the principle of fluorescence resonance energy transfer (FRET) for the construction of the turn-on quantum dot sensor. With a detection limit for chlorpyrifos as low as 10 ppb (10 μg/L), the QDs sensor exhibits notable resistance to interference from various pesticides. Application of this system to detect organophosphorothioate pesticides in apples produced results consistent with those obtained from high-performance liquid chromatography (HPLC) detection, affirming the promising application prospects of this sensing system for the rapid detection of OPPs residues.

A Review on Extraction and Chromatographic Techniques for Organophosphate Pesticidal Residue Analysis in Paddy and Rice Bran

Organophosphorus pesticides (OPPS) are extensively employed in agricultural techniques and may expose people to them via food intake. We offer an analytical approach for detecting OPPS in paddy, rice grains and or rice bran that combines solid-phase extraction with a high-performance liquid chromatography detector. Acetonitrile extraction was used before SPE–HPLC–MSMS to isolate specific residues, which helped decrease matrix disruptions and identify a broad array of numerous residues in rice grains. Accordingly, ranges of quantitative determination ranged from 0.01mg/kg to more than 1.0 mg/kg, with coefficients extending from 0.995 to more than 0.999. At three stimulating intensities, high recuperation was reported, suggesting excellent precision. The relative SD of all residues confirmed the technique’s accuracy. Using this, various OPPS were quantified, ranging from just below to maximum permissible limits to exceeding the limit. According to a sample study of different rice grain varieties accessible in the international market. This study focuses on the techniques of organophosphate pesticide residue extraction from paddy and rice ban. The study further discusses chromatographic techniques for the same.

Split-ring resonator with interdigital Split electrodes as detector for liquid and ion chromatography

The analysis of food and drugs as well as the monitoring of chemical processes and bioreactors by high-performance liquid chromatography and ion chromatography requires universal, cost-effective, and sensitive detectors. Therefore, this work presents a split-ring resonator that detects changes in the electrical and dielectric properties of the eluate from liquid chromatography or ion chromatography by monitoring the amplitude of the transmitted signal using an envelope detector. The used split-ring resonator consists of a simple printed circuit board featuring two microstrip lines. One is formed to a ring with interdigital split electrodes. The interdigital split electrodes forming the sensitive area significantly enhance the sensitivity to changes in relative permittivity, dielectric losses and electrical conductivity of the eluate In addition, the split-ring resonator is a small, inexpensive and easy-to-use detector that uses several dielectric parameters simultaneously for the measurement. Furthermore, the split-ring resonator measures these parameters at a significantly lower frequency than optical detectors and therefore measures different changes in frequency-dependent permittivity. For demonstrating feasibility of a split-ring resonator as a detector for high-performance liquid chromatography and ion chromatography, various anion and cation standards, basic and acidic amino acids, sugars, as well as sugar alcohols were separated and detected. A conductivity detector for ion chromatography and a refractive index detector for high-performance liquid chromatography were used as reference detectors.

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

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

A Multi-step High-Performance Liquid Chromatography (HPLC) Technique for the Extraction and Purification of Medical-Grade Cyclosporine A

Cyclosporine A (CsA), a potent immunosuppressive drug, is used to treat autoimmune diseases and prevent organ transplant recipients from rejecting their new organs. Maintaining CsA's uniformity and purity is essential to maintaining its therapeutic efficacy and safety. Impurities and contaminants in CsA formulations can exacerbate side effects and patient toxicity. Purification processes can improve the safety profile of the drug and reduce the likelihood of adverse effects by eliminating impurities. Using High-performance liquid chromatography (HPLC) methods, CsA has been isolated and refined from crude in recent years. However, after the procedure, the CsA purity was not at its best. To solve this issue, this work employs a multi-step HPLC method to increase purity levels to above 95%. When exploring the HPLC detection conditions of CsA, we found that the method from the Chinese pharmacopoeia: acetonitrile-water-tert-butyl methyl ether-phosphoric acid (430 : 520 : 50 : 1) was a better mobile phase solution, our further research, including the substitution of tert-butyl methyl ether with other buffer solvents, showed no significant improvement. At the same time, we established that the key factor affecting its separation was temperature. When the temperature is lower than 70 ℃, the HPLC separation effect worsens, the retention time increases, and the peak width becomes longer. Finally, the utilization of acetonitrile-water-tert-butyl methyl ether-phosphoric acid (430 : 520 : 50 : 1) as the mobile phase with a column temperature of 70 °C, petroleum ether: acetic acid Ethyl ester (70 : 30) as the mobile phase, and filling the φ 40 mm × 500 mm chromatography column using a 40~60 μm silica gel so that a 10 : 1 height-to-diameter ratio of the packed part is obtained, under normal temperature conditions, resulted in an average cyclosporine A yield of 80.1%. The corresponding average purity was 97.2%, of which the first isolation yield was 82.3%, and the purity was 98.1%.

The Effect of Bacterial AHL on the Cyclic Adenosine Monophosphate Content in Plants According to High-Performance Liquid Chromatography.

Cyclic adenosine monophosphate (cAMP) is an important second messenger in cells, mediating various stimulation signals such as the growth and development of organisms and stress and participating in regulating various biological processes of cells. This article explores the quantitative determination of cAMP in plants using High-Performance Liquid Chromatography (HPLC) and applies this method to analyzing the changes in cAMP content during the process of plant response to the bacterial quorum sensing signal N-acyl homoserine lactone (AHL). Research has shown that the optimal detection conditions for HPLC are as follows: the chromatographic column is Venusil MP C18 (2), the mobile phase is methanol-water (0.1% trifluoroacetic acid) (v:v, 10:90), the detection wavelength is 259 nm, the column temperature is 35 °C, and the flow rate is 0.8 mL/min. The precision of the standard sample of this method is 98.21%, the precision of the sample is 98.87%, and the recovery rate is 101.067%. The optimal extraction conditions for cAMP in Arabidopsis are to use 15% methanol ultrasonic extraction for 10 min, followed by a 40 °C water bath for 4 h. Bacterial AHL signal processing can significantly stimulate an increase in cAMP levels in Arabidopsis leaves and roots. The establishment of HPLC detection methods for the cAMP content in plants is of great significance for in-depth research on the signal transduction mechanisms of plant-bacterial interactions.

Transcriptome and comparative chloroplast genome analysis of Taxus yunnanensis individuals with high and low paclitaxel yield

Paclitaxel is a potent anti-cancer drug that is mainly produced through semi-synthesis, which still requires plant materials as precursors. The content of paclitaxel and 10-deacetyl baccatin III (10-DAB) in Taxus yunnanensis has been found to differ from that of other Taxus species, but there is little research on the mechanism underlying the variation in paclitaxel content in T. yunnanensis of different provenances. In this experiment, the contents of taxoids and precursors in twigs between a high paclitaxel-yielding individual (TG) and a low paclitaxel-yielding individual (TD) of T. yunnanensis were compared, and comparative analyses of transcriptomes as well as chloroplast genomes were performed. High-performance liquid chromatography (HPLC) detection showed that 10-DAB and baccatin III contents in TG were 18 and 47 times those in TD, respectively. Transcriptomic analysis results indicated that genes encoding key enzymes in the paclitaxel biosynthesis pathway, such as taxane 10-β-hydroxylase (T10βH), 10-deacetylbaccatin III 10-O-acetyltransferase (DBAT), and debenzoyl paclitaxel N-benzoyl transferase (DBTNBT), exhibited higher expression levels in TG. Additionally, qRT-PCR showed that the relative expression level of T10βH and DBAT in TG were 29 and 13 times those in TD, respectively. In addition, six putative transcription factors were identified that may be involved in paclitaxel biosynthesis from transcriptome data. Comparative analysis of plastid genomes showed that the TD chloroplast contained a duplicate of rps12, leading to a longer plastid genome length in TD relative to TG. Fifteen mutation hotspot regions were identified between the two plastid genomes that can serve as candidate DNA barcodes for identifying high-paclitaxel-yield individuals. This experiment provides insight into the difference in paclitaxel accumulation among different provenances of T. yunnanensis individuals.

Silver nanoparticle-functionalized melamine-formaldehyde aerogel for online in-tube solid-phase microextraction of polycyclic aromatic hydrocarbons followed by HPLC-DAD analysis

Based on the π-metal interaction between silver nanoparticles (AgNPs) and aromatic compounds, AgNPs were in-situ grown to melamine-formaldehyde (MF) aerogel for improving the extraction performance to polycyclic aromatic hydrocarbons (PAHs). The AgNPs/MF aerogel was regulated through varing the concentration of reactants, and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray powder diffraction. As a new extraction coating, the AgNPs/MF aerogel was coated to stainless-steel wires for in-tube solid-phase microextraction (IT-SPME). The extraction effects of MF aerogels before and after the modification of AgNPs were compared, and the AgNPs greatly improved the extraction ability for PAHs reaching to 166.4 %. Combining IT-SPME with high performance liquid chromatographic detection, an online analytical system was constructed. Furthermore, the sampling volume and rate, concentration of organic solvent, and desorption time were optimized factor by factor. The online analytical method with low detection limits (0.003–0.010 μg L−1) and efficient enrichment factors (1998–3237) for PAHs was established, which fastly detected trace level of PAHs in drinking and environmental water samples. Compared with other methods, the method was comparable or better in the detection limit and linear range, indicating prospective application of the AgNPs/MF aerogel for sample preparation.

Amperometric Inkjet-Printed Thyroxine Sensor Based on Customized Graphene and Tunned Cyclodextrins as the Preconcentration Element.

The determination of thyroid hormones has practical clinical significance for the diagnosis of hyperthyroidism and hypothyroidism diseases. Considering this aspect, a wide range of analytical methods for the detection of analytes, including immunoassay, chemiluminescence, mass spectroscopy and high-performance liquid chromatography, among others, has been developed. This type of analysis provides feasible results. Nevertheless, it requires qualified staff, special facilities and is time-consuming. For this reason, this paper relies on the fabrication of an electrochemical device developed with inkjet printing technology for the free detection of Thyroxine (T4). To manufacture our electrochemical device, several aspects were considered from the use of materials that amplify electrical signals, to finding a supramolecular scaffold that possess affinity towards the target analyte and the need of preconcentrating the analyte on the electrode's surface. For this task, printed devices were modified with a hybrid nanomaterial consisting of reduced graphene oxide (rGO) tuned with Au nanoparticles (Au-NPs) and an entrapment agent and different thiolated cyclodextrins (x-CD-SH) as carrying agents. Analytes were preconcentrated via supramolecular chemistry due to the formation of an inclusion complex between the cyclodextrin and hormones. Morphological and electrochemical characterization of the final device was carried out to ensure the proper workability of the electrode, achieving excellent response, sensitivity and limit of detection (LOD).

Determination of Aflatoxin B1 in Grains by Aptamer Affinity Column Enrichment and Purification Coupled with High Performance Liquid Chromatography Detection.

Aflatoxin B1 (AFB1) is a highly teratogenic and carcinogenic secondary metabolite produced by Aspergillus. It is commonly detected in agricultural products such as cereals, peanuts, corn, and feed. Grains have a complex composition. These complex components severely interfere with the effective extraction and separation of AFB1, and also cause problems such as matrix interference and instrument damage, thus posing a great challenge in the accurate analysis of AFB1. In this study, an aptamer affinity column for AFB1 analysis (AFB1-AAC) was prepared for the enrichment and purification of AFB1 from grain samples. AFB1-AAC with an AFB1-specific aptamer as the recognition element exhibited high affinity and specificity for AFB1. Grain samples were enriched and purified by AFB1-AAC, and subsequently analyzed by high performance liquid chromatography with post-column photochemical derivatization-fluorescence detection (HPLC-PCD-FLD). The average recoveries of AFB1 ranged from 88.7% to 99.1%, with relative standard deviations (RSDs) of 1.4-5.6% (n = 3) at the spiked levels of 5.0-20.0 μg kg-1. The limit of detection (LOD) for AFB1 (0.02 μg kg-1) was much below the maximum residue limits (MRLs) for AFB1. This novel method can be applied to the determination of AFB1 residues in peanut, corn, and rice.

Preconcentration of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in Clinical Samples by Various Hollow Fiber–Liquid Phase Microextraction (HF-LPME) Configurations With High-Performance Liquid Chromatography (HPLC) Detection

Hollow fiber liquid-phase microextraction is commonly used in analytical chemistry, providing high clean-up and pre-concentration factors. However, a major issue with this method is the long extraction time. The objective of this project is to reduce the extraction time by inducing different types of fluid motion in the sample solution. Three methods were employed: agitation using a magnetic stir bar in the horizontal position (conventional method), utilization of an air pump, and agitation using a magnetic stir bar in the vertical position for the pre-concentration and determination of non-steroidal anti-inflammatory drugs (naproxen, ibuprofen, and mefenamic acid) in biological samples via high-performance liquid chromatography with ultraviolet absorbance detection. The results demonstrated a significant reduction in extraction time and limit of detection when the air pump was employed compared to the conventional method of stirring with a magnetic stir bar in the horizontal position. Moreover, the mentioned parameters were even lower when stirring solutions were accomplished using a vertically-positioned magnetic stir bar, surpassing the method utilizing the air pump for agitation. Furthermore, the relative standard deviations were also lower when a vertically-positioned magnetic stir bar was used compared to the conventional method with a horizontally-positioned magnetic stir bar, while those of the air pump-assisted agitation method fell between the values of the aforementioned methods.

Preparation of branched polyethyleneimine-assisted boronic acid-functionalized magnetic MXene for the enrichment of catecholamines in urine samples.

Herein, a magnetic borate-functionalized MXene composite with multiple boronic affinity sites was fabricated by embedding Fe3 O4 nanoparticles with 4-formylphenylboronic acid functionalized Ti3 C2 Tx nanosheets and served as sorbent for the simultaneous extraction of catecholamines (CAs) in urine samples. The morphology and structure of the magnetic materials were investigated using scanning microscopy, vibrating sample magnetometer, X-ray photoelectron spectrometer, and X-ray diffraction. The introduction of polyethyleneimine can amplify the bonded boronic acid groups, thereby effectively improving the adsorption capacities for CAs based on the multiple interactions of boronic affinity, hydrogen bonding, and metal coordination. The adsorption performance was investigated using the kinetics and isotherms models, and the main parameters that influence the extraction efficiency were optimized. Under the most favorable magnetic solid-phase extraction condition, a sensitive method for the analysis of CAs in urine samples was developed by combining magnetic solid-phase extraction conditions with high-performance liquid chromatography detection. The findings illustrated that the proposed approach possessed a wide linearity range of 0.05-250ng/mL with an acceptable correlation coefficient (R2 ≥0.9984) and detection limits of 0.010-0.015ng/mL for the target CAs. The research not only provides a notable composite with multiple boronic affinity sites but also offers an effective and feasible measure for the detection of CAs in biological samples.

Establishment and Optimization of Flavonoid Extraction and Detection System for Hemerocallis

Hemerocallis is a characteristic vegetable with outstanding edible and medicinal value. Flavonoids are important bioactive components of Hemerocallis. To improve the extraction efficiency and detection accuracy of flavonoids from Hemerocallis, we established a high-performance liquid chromatography (HPLC) detection system, which can simultaneously detect multiple flavonoids. In addition to the previously developed organic solvent extraction method, an ultrasonic-assisted extraction technique that uses fewer samples was established to extract flavonoids from Hemerocallis. The extraction conditions of the ultrasonic-assisted extraction were optimized via a single-factor experiment and a response surface experiment. The HPLC system detected and determined the contents of rutin, isoquercetin, myricetin, quercetin, apigenin, and diosmetin from 70 Hemerocallis germplasm resources. In addition, we evaluated the antioxidant activity of flavonoids in Hemerocallis using DPPH free radical scavenging capacity with ascorbic acid (Vc) as a positive control. The results showed that the optimum conditions for the ultrasonic extraction process were as follows: sample weight of 0.25 g, ethanol volume fraction of 72%, ethanol volume of 2.5 mL, and ultrasonic extraction time of 17 min. Under these conditions, flavonoid extraction had a strong scavenging effect on DPPH. With the increase in the sample solutions’ concentrations, its antioxidant capacity was gradually enhanced, and the DPPH scavenging rate reached 70.2%. The optimized ultrasonic-assisted extraction technology can increase the total content of six flavonoids in day lily bud by 59.01%, especially the content of rutin (increased by 64.41%) in Hemerocallis flower buds. Among 70 Hemerocallis plant resources, we selected materials H0087 and H0059 with high and stable flavonoid content, with the total content of six substances being 4390.54 ug/g and 3777.13 ug/g. Thus, this study provides a reference for extracting and determining flavonoid contents in Hemerocallis materials. It also provides a theoretical basis for high-quality individual plant breeding.

Molecularly imprinted polymer membranes based on single template for recognition and extraction of carbamazepine and its structurally analogues

In this work, a novel molecularly imprinted polymer membrane (MIPM) using oxcarbazepine (OXC) as the single template and polyvinylidene difluoride membrane as the subtract was fabricated for recognition and extraction of carbamazepine (CBZ) and its analogues including OXC, carbamazepine-10,11-epoxide (CBZE), and monohydroxy derivative 10, 11-dihydro-10-hydroxy carbamazepine (MHD). The prepared MIPMs were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, Brunaner-emmet-teller measurements and X-ray photoelectron spectroscopy, showing the successful construction of uniform and porous polymers on the surface of membranes. A series of adsorption affinity tests were investigated, indicating the prepared materials had specific recognition capacity and excellent stability as novel sorbents. The maximum static adsorption capacities of MIPMs towards OXC, CBZ, MHD or CBZE was 4.246, 3.621, 2.316, or 4.877 mg·g−1, respectively. The MIPMs showed reusability and reproducibility. The usability of MIPMs was evaluated by combining MIPMs extraction and high performance liquid chromatography detection for the determination of CBZ, CBZE, OXC and MHD in different matrices including methanol, normal saline, phosphate buffer solution, and plasma. The mean recovery of four target compounds in methanol, normal saline and phosphate buffer solution was more than 75 %, while the mean recovery of CBZ and CBZE in plasma was more than 80 %. The results demonstrated that the proposed MIPMs is very suitable for the determination of OXC, CBZ, MHD and/or CBZE in different matrices.

Smartphone as a fluorescence detector for high-performance liquid chromatography

BackgroundFluorescence detection is employed in high-performance liquid chromatography (HPLC) due to its high specificity and sensitivity. However, it is often limited by expensive components and bulkiness. Recently, advances in technology and electronics have led to the development of smartphones that can serve as portable recording, analysis, and monitoring tools. Smartphone-based detection provides advantages of cost effectiveness, rapid signal/data processing, and the display of results on a handhold monitor. The combination of smartphone-based detection with HPLC can offer unique features that are beneficial in overcoming limitations of commercial fluorescence detectors. (90) ResultsA miniaturized and low-cost HPLC fluorescence detector based on a smartphone is introduced for the detection of six fluorescent molecules. The smartphone is able to capture emitted fluorescence in video format while MATLAB code is used for data processing to provide chromatograms based on different detection channels. A custom designed double-channel flow cell was utilized to enable simultaneous detection of fluorescent compounds with different excitation wavelengths. The detector consists of a lab-made flow cell, monochromatic LEDs as the light source, 3D printed housing and connector box, fiber optic cables, and a smartphone. The effects of flow cell geometry, channel width and light slit diameter, as well as a comparison of different flow cell manufacturing techniques, are studied and discussed. The validated system was successfully applied to samples from diverse water sources, yielding spiking recoveries within the range of 91.7% and 109.7%. (141) SignificanceThis study introduces the first smartphone-based fluorescence detector for HPLC with cost-effective and customizable flow cells, allowing for the simultaneous detection of fluorescent compounds with different excitation wavelengths and offering a potential solution for the analysis of co-eluting compounds. Beyond its user-friendly interface and low-cost, smartphone detection in HPLC provides tremendous opportunities in further miniaturizing chromatographic instrumentation while offering high sensitivity and can be expanded to other mechanisms of detection. (70)

Advances in Extraction Techniques for Beer Flavor Compounds

Owing to the unique chemical properties exhibited by beer flavor compounds, different extraction methods have been utilized to extract these compounds from the sample matrix. Carbonyl compounds, which significantly contribute to flavor instability in beer, pose challenges in detection due to their low concentrations and reactivity. Consequently, the analysis of beer flavor compounds has focused on improving sensitivity and specificity through techniques that minimize sample preparation requirements and reduce interactions between factors involved in the analysis. Notably, extraction techniques such as headspace solid-phase microextraction (HS-SPME), stir bar sorptive extraction (SBSE), and gas diffusion microextraction (GDME) have been successfully applied to the analysis of carbonyl compounds in alcoholic beverages, including beer. Derivatization agents like 2,4-dinitrophenylhydrazine (DNPH) and O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) enhance the volatility and stability of analytes, facilitating their separation and detection in gas chromatography and high-performance liquid chromatography. Chromatographic separation methods, particularly gas chromatography and liquid chromatography, are extensively employed to identify and quantify aroma/flavor compounds in various foodstuffs, including beer. This review provides a comprehensive overview of extraction techniques and chromatographic methods used in the analysis of beer compounds.

Synthesis of novel hydroxyl-functionalized hyper-crosslinked polymer for extraction of phenylurea herbicides from environmental waters

Water resources are frequently contaminated by organic micropollutants (OMPs), which present a significant peril to ecosystem and well-being of the people. Phenylurea herbicides (PUHs) are an important class of OMPs since they are widely used in modern agriculture. However, efficient extraction of PUHs from water is of challenge because of their high water affinity. Therefore, the synthesis of novel adsorbent capable of effectively extracting PUHs from water is urgently needed. Here, three novel hydroxyl-functional hyper-crosslinked polymers (HCPs) were synthesized through Friedel-Crafts reaction by using the brominated β-cyclodextrin, i.e., heptakis(6-bromo-6-deoxy)-β-CD) [(CD-(Br)7)], as the building unit. Among them, PQ-CD-HCP, which was synthesized by using p-quaterphenyl (PQ) and CD-(Br)7, had the best adsorption capability for the PUHs. Finally, the quantitative determination of the PUHs for environmental waters was realized by using the PQ-CD-HCP as the solid-phase adsorbent in conjunction with high-performance liquid chromatographic detection. Under the optimal conditions, the limits of detection for environmental water samples were 0.02–0.05 ng mL−1. The method recoveries were 86.0%-116.5% with the relative standard deviations ≤ 7.8%. The PQ-CD-HCP also showed good adsorption performance for other OMPs such as triazine herbicides, chlorophenols, polycyclic aromatic hydrocarbons, endocrine disruptors, nitroimidazoles and benzoylureas insecticides, indicating its good application prospect. The adsorption experiments show that the PQ-CD-HCP extracts the analytes by encapsulation, π-stacking, hydrophobic and hydrogen bonding interactions.

Green construction of hydroxyl-functionalized magnetic porous organic framework for effective extraction of triazine herbicides from environmental water and watermelon juice samples

Triazine herbicides have been widely detected in water resources and food, which poses a potential hazard to both ecosystem and human health. Due to their high polarity, conventional adsorbents have limitations for their extractions. Herein, for the effective magnetic extraction of triazine herbicides, a novel and effective magnetic adsorbent was prepared with a satisfactory extraction performance. In the experiments, five porous organic frameworks (POFs) with hydroxyl functional groups were synthesized by diazo-coupling reactions in aqueous solution with β-cyclodextrin (β-CD) as a green monomer. After evaluation of the five POFs, the DDM-CD-POF, which was synthesized with 4′4-diaminodiphenylmethane (DDM) and β-CD, showed the largest specific surface area and the best adsorption capacity for the five triazine herbicides. Then, it was magnetized by introducing Fe3O4@SiO2 into it to prepare a magnetic adsorbent (M-DDM-CD-POF) to facilitate separation and recycling. Finally, the M-DDM-CD-POF-based magnetic solid-phase extraction in combination with high performance liquid chromatographic detection method was established for the quantitative determination of the triazine herbicides in environmental water and watermelon juice samples. The current strategy showed low limits of detection of 0.03–0.11 ng mL−1 for environmental water and 0.07–0.22 ng mL−1 for watermelon juice sample. The method recoveries for spiked samples ranged from 84.0% to 113.0% with the relative standard deviations ≤8.8%. This work provides a new approach for the detection of the triazine herbicides with good application prospect.