Acid-ethylene Glycol Dimethacrylate Research Articles

Endosulfan pesticide detection using an electrochemical sensor based on molecularly imprinted polymer (MIP)

Abstract Pesticides and herbicides are active chemicals used to eradicate plant pests which constitute contamination if they exceed the threshold for the environment and humans. Molecularly Imprinted Polymer (MIP) is a technique for making polymers that are obtained from cross-linked polymers and have cavities that match the template, where the cavities function as a medium for mechanical interaction of molecules with the same size, shape, structure, and physicochemical properties. The polymer produced from the MIP technique is applied to the surface of the sensor material as an endosulfan detection. This research aims to create an endosulfan MIP to obtain a potentiometric MIP sensor capable of detecting endosulfan. The results showed that the optimum conditions for making MIP endosulfan were obtained with a composition of 6.02 mL of chloroform; 0.025 g endosulfan; 0.9 mL methacrylic acid (MAA); 1.57 mL ethylene glycol dimethacrylate acid (EGDMA); 0.07 g benzoyl peroxide with a heating time of 150 minutes at a temperature of 70 °C. The sensor performance test was carried out potentiometrically and it was found that the MIP endosulfan sensor that was made had sensitivity and stability in the concentration range of 0.01-1.0x10−6 ppm with a lifetime up to 90 days.

Molecularly Imprinted Polymer Modified with an MWCNT Nanocomposite for the Fabrication of a Barbital Solid-Contact Ion-Selective Electrode.

For potentiometric sensing of barbital (BAR), unique micro-sized imprinted polymer/multiwalled carbon nanotube (MWCNT)-based sensors are introduced. MWCNT is a lipophilic ion-to-electron transducing substance. A synthetic, described, and integrated barbital sodium molecular imprinted polymer (MIP) was used as a recognition receptor for potentiometric transduction in a plasticized polyvinyl chloride membrane. Methacrylic acid and ethylene glycol dimethacrylic acid are used as the functional monomer and crosslinking agent, respectively, in the synthesis of the MIPs. In the operating concentration range of 1.0 × 10–3 to 2.0 × 10–7 M, the sensors’ Nernstian slope was −56.8 ± 0.9 mV/decade, with a detection limit of 1.0 × 10–7 M. The sensor displayed an accurate response time of 10 s and consistent potential response in the pH range of 8.5–11. Using chronopotentiometry tests, the interfacial capacitance of the presented ion-to-electron transducer was assessed. When compared to sensors without MWCNTs, the interfacial double-layer capacitance for sensors based on those layers reached 52.5 μF. After the addition of the MWCNTs nanocomposite layer, the water layer was eliminated between the sensing membrane and the conducting substrate. A wide range of applications for the proposed sensors for BAR detection in real samples can be provided by the sensors’ strong selectivity over the interfering species. The suggested sensors were successfully used to determine BAR in urine samples that had been spiked.

Determination of ligustrazine in rat serum by polymer monolithic micro-extraction combined with ultra high performance liquid chromatography-tandem mass spectrometry

AbstractThis study focused on developing an effective and environmentally friendly method to measure ligustrazine in rat serum by using polymer monolith micro-extraction (PMME) technique. A poly (methacrylic acid-ethylene glycol dimethacrylate) material was used to extract ligustrazine through hydrophobic and ion-exchange interaction. Qualitative and quantitative analysis was performed by a liquid chromatography and tandem mass spectrometry. After optimization of several PMME conditions, the developed method exhibited excellent extraction performance to the ligustrazine. Good linearity was acquired ranging from 10 to 2,000 ng mL−1, and the limit of detection of the proposed method was 0.14 ng mL−1. The recoveries measured by spiking three different concentrations in rat serum ranged from 82.6 to 95.3%, and excellent precision was found with relative standard deviations (RSDs) less than 8.3% for intra-day and 9.7% for inter-day, respectively. At last, the applicability of the method was further confirmed through continuous monitoring of ligustrazine in rat serum after dosing of ligustrazine tablets to rats.

Liquid Contact-Selective Potentiometric Sensor Based on Imprinted Polymeric Beads Towards 17β-Estradiol Determination.

Novel potentiometric devices “ion-selective electrodes (ISEs)” were designed and characterized for the detection of 17β-estradiol (EST) hormone. The selective membranes were based on the use of man-tailored biomimics (i.e., molecularly imprinted polymers (MIPs)) as recognition ionophores. The synthesized MIPs include a functional monomer (methacrylic acid (MAA)) and a cross-linker (ethylene glycol dimethacrylic acid (EGDMA)) in their preparation. Changes in the membrane potential induced by the dissociated 17β-estradiol were investigated in 50 mM CO32−/HCO3− buffer solution at pH 10.5. The ion-selective electrodes (ISEs) exhibited fast response and good sensitivity towards 17β-estradiol with a limit of detection 1.5 µM over a linear range starts from 2.5 µM with an anionic response of 61.2 ± 1.2 mV/decade. The selectivity pattern of the proposed ISEs was also evaluated and revealed an enhanced selectivity towards EST over several phenolic compounds. Advantages revealed by the presented sensor (i.e., wide range of assay, enhanced accuracy and precision, low limit of detection, good selectivity, long-term potential stability, rapid response and long life-span and absence of any sample pretreatment steps) suggest its use in routine quality control/quality assurance tests. They were successfully applied to estradiol determination in biological fluids and in different pharmaceutical preparations collected from the local market.

Recyclable Cu(II)-(MAA-EGDMA) catalyst for selective oxidation of alcohols to aldehydes using sodium hypochlorite

Copper(II) α-benzoin oxime complex was synthesized by the reaction between copper(II) benzoate and α-benzoin oxime. The poly methacrylic acid-ethylene glycol dimethacrylate (MAA-EGDMA) was applied as support of copper complex catalyst for oxidation of alcohols to aldehydes using NaClO. The structure and morphology of immobilized Cu(II)-benzoin oxime have been studied by using different analysis including Fourier Transform Infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and Thermal Gravimetric Analysis (TGA). The yield of aldehydes was determined by Gas Chromatography (GC) analysis. The immobilized Cu(II)-benzoin oxime indicated a high catalytic activity compared to its absence for the alcohol oxidation with sodium hypochlorite. The effect of the reaction time and temperature, the solvent type, the amounts of catalyst and NaClO were optimized to obtain maximum yield. The prepared catalyst had various benefits such as being inexpensive, environmentally friendly manner, recyclable, reducing the reaction time and increasing the yield. A reaction mechanism is proposed for oxidation of alcohols in the presence of the catalyst.

Imprinted Polymeric Beads-Based Screen-Printed Potentiometric Platforms Modified with Multi-Walled Carbon Nanotubes (MWCNTs) for Selective Recognition of Fluoxetine.

Herein, we present a new validated potentiometric method for fluoxetine (FLX) drug monitoring. The method is based on the integration of molecular imprinting polymer (MIP) beads as sensory elements with modified screen-printed solid contact ion-selective electrodes (ISEs). A multi-walled carbon nanotube (MWCNT) was used as a nanomaterial for the ion-to-electron transduction process. The prepared MIP beads depend on the use of acrylamide (AAm) and ethylene glycol dimethacrylic acid (EGDMA) as a functional monomer and cross-linker, respectively. The sensor revealed a stable response with a Nernstian slope of 58.9 ± 0.2 mV/decade and a detection limit of 2.1 × 10−6 mol/L in 10 mmol/L acetate buffer of pH 4.5. The presented miniaturized sensors revealed good selectivity towards FLX over many organic and inorganic cations, as well as some additives encountered in the pharmaceutical preparations. Repeatability, reproducibility and stability have been studied to evaluate the analytical features of the presented sensors. These sensors were successfully applied for FLX assessment in different pharmaceutical formulations collected from the Egyptian local market. The obtained results agreed well with the acceptable recovery percentage and were better than those obtained by other previously reported routine methods.

Methacrylic acid-ethylene glycol dimethacrylate polymeric sorbent for the removal of estrogens from water

Methacrylic acid-ethylene glycol dimethacrylate polymeric sorbent for the removal of estrogens from water

Molecularly imprinted based solid phase microextraction method for monitoring valproic acid in human serum and pharmaceutical formulations

In this paper, a straightforward method is presented to detect valproic acid after its microextraction. Molecularly imprinted polymer fiber was used in conjunction with chromatography-flame ionization to achieve this goal. A narrow bore silica capillary was adopted as a mold, via the copolymerization of meth acrylic acid–ethylene glycol dimethacrylate imprinted with VPA, to synthesize the fiber. Extraction temperature, extraction time, salt addition, pH, stirring rate, and desorption temperature—all of which are factors that can influence the extraction process—were measured, and adjusted accordingly. Linearity, precision, and detection limits, as analytical elements, were also evaluated under optimum conditions. Readings showed a linear range of 0.03–100 µg L− 1 (r2 = 0.998), and the limit of detection was measured as 0.01 µg L− 1. The established method was then applied in selective detection of valproic acid in tablet, syrup and human serum samples successfully.

Preparation, characterisation, drug loading and release properties of a novel KIT‐6/poly(AA‐EGDMA) nanocomposite

A KIT-6/poly(acrylic acid-ethylene glycol dimethacrylate) (KIT-6/Poly(AA-EGDMA) nanocomposite was synthesised as an adequate carrier. KIT-6 as a three-dimensional cubic symmetric structure was prepared by the sol-gel method. Polymerisation was carried out through the in situ method in which EGDMA was cross-linked by AA inside KIT-6 pores. This mesostructure acts as a smart uptake and release of the ibuprofen (IBU) system. Diverse characterisation techniques including Fourier transform infrared spectroscopy, X-ray powder diffraction, Brunauer-Emmett-Teller, thermal gravimetric, scanning electron microscopy and ultraviolet-visible spectroscopy were employed to determine the relationship between the carrier nature and drug release performance. The KIT-6/Poly(AA-EGDMA) was modified by changing the ratio of the polymer and IBU as well as its time-loading. The results proved that the KIT-6/Poly(AA-EGDMA) has the ability of drug adsorption and slow release in a simulated body fluid.

Design and development of guar gum based novel, superabsorbent and moisture retaining hydrogels for agricultural applications

The novel hydrogels were synthesized by grafting guar gum with acrylic acid and cross-linking with ethylene glycol di methacrylic acid (EGDMA). The synthesis of hydrogel was confirmed by characterization through 13C NMR, FTIR spectroscopy, SEM micrography, thermo-gravimetric analysis and water absorption studies under different solutions. Synthesized hydrogel (GG-AA-EGDMA) was confirmed to be biodegradable with half-life period of 77 days through soil burial biodegradation studies. The effects of hydrogel treatment on soil were evaluated by studying various physico-chemical properties of soil like bulk density, porosity, water absorption and retention capacity etc. The hydrogel which could absorb up to 800 ml water per gram, after addition to soil, improved its porosity, moisture absorption and retention capacity significantly. Water holding capacity of water increased up to 54% of its original and porosity also increased up to 9% of its original. The synthesized hydrogel revealed tremendous potential as soil conditioning material for agricultural applications.

Spectrofluorimetric determination of atenolol from human urine using high-affinity molecularly imprinted solid-phase extraction sorbent.

This study presents a novel, sensitive and selective molecularly imprinted solid-phase extraction (MISPE)-spectrofluorimetric method for the removal and determination of atenolol from human urine. Molecularly imprinted and non-imprinted polymers were synthesized thermally using a radical chain polymerization technique and used as solid-phase extraction sorbents. Acrylic acid ethylene glycol dimethacrylate, dibenzoyl peroxide and dichloroethane were used as a functional monomer, cross-linker, initiator and porogen, respectively. The calibration curve was in the range of 0.10-2.0μg/ml for the developed method. Limit of detection and limit of quantification values were 0.032 and 0.099μg/ml, respectively. Owing to the selectivity of the MISPE technique and the sensitivity of spectrofluorimetry, trace levels of atenolol have been successfully determined from both organic and aqueous media. Relatively high imprinting factor (4.18) and recovery results (74.5-75.3%) were obtained. In addition, intra- and interday precision values were 0.38-1.03% and 0.47-2.05%, respectively, proving the precision of the proposed method. Thus, a selective, sensitive and simple MISPE-spectrofluorimetric method has been developed and applied to the direct determination of atenolol from human urine.

Poly(methacrylic acid-ethylene glycol dimethacrylate-N-vinylcarbazole) monolithic column for the enrichment of trace benzodiazepines from urine and beer samples.

A sensitive microextraction method based on a new poly(methacrylic acid-ethylene glycol dimethacrylate-N-vinylcarbazole) monolithic capillary column, coupled with gas chromatography and electron capture detection, was established for the determination of three benzodiazepines (estazolam, alprazolam, and triazolam) in urine and beer samples. Owing to the abundant π electrons and polar surface of N-vinylcarbazole, N-vinylcarbazole-incorporated monolith showed a higher extraction performance than neat poly(methacrylic acid-ethylene glycol dimethacrylate) because of the enhanced π-π stacking interactions derived from the π-electron-rich benzene groups from N-vinylcarbazole. The monolith exhibited a homogeneous and continuous structure, good permeability, and a long lifetime. Factors affecting the extraction such as solution pH, salt concentration, sample volume, desorption solvent, and desorption volume were investigated. Under the optimized conditions, limits of detection of 0.011-0.026ng/mL were obtained. The one-column and column-to-column precision values were ≤7.2 and ≤9.8%, respectively. The real samples were first diluted with deionized water and then treated by the monolith microextraction before gas chromatography analysis. The recoveries were 81.4-93.3 and 83.3-94.7% for the spiked samples, with relative standard deviations of 4.1-8.1 and 3.8-8.5%, respectively. This method provides an accurate, simple, and sensitive detection platform for drug analysis.

Selective determination of thidiazuron herbicide in fruit and vegetable samples using molecularly imprinted polymer fiber solid phase microextraction with ion mobility spectrometry detection (MIPF-SPME-IMS)

In this study, we use corona discharge ion mobility spectrometry (CD-IMS) as a detection technique for determining thidiazuron (TDZ) after its selective microextraction using molecularly imprinted polymer (MIP) fibers. This is the first time that MIP fiber solid phase microextraction-ion mobility spectrometry (MIPF-SPME-IMS) was used to detect TDZ. The fiber was synthesized simply using a narrow bore silica capillary as a mold by the copolymerization of methacrylic acid–ethylene glycol dimethacrylate imprinted with TDZ. The prepared MIPs were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM). The obtained flexible MIP monolithic fibers have high chemical and thermal stabilities with good selectivity to TDZ. The effective parameters influencing the polymerization were also investigated. In addition, the influences of different factors such as pH, extraction time, desorption solvent, and temperature on the extraction efficiency of the analyte were investigated. Under the optimum conditions, analytical parameters such as linearity, precision and limit of detection were also evaluated. The linear range was in the range of 0.01–20μgL−1 (r2=0.9980) and the limit of detection was 0.005μgL−1. Intra- and inter-day precisions were satisfactory with a relative standard deviation (RSD) of 0.9% and 2%, respectively. Finally, the established MIPF-SPME-IMS method was successfully applied in the selective determination of TDZ residues in fruit and vegetable samples.

Polymeric Colloidal Nanostructures Fabricated via Highly Controlled Convective Assembly and Their Use for Molecular Imprinting.

In this work, the formation of various polystyrene (PS) colloidal structures on striped PS patterns is demonstrated based on a simple and novel convective assembly method that controls the electrostatic interactions between the PS colloidal particles and sodium dodecyl sulfate (SDS). Under the optimal conditions (different withdrawal speeds, channel dimensions, suspension concentrations, etc.), highly ordered structures such as highly close-packed, zigzag, and linear colloidal aggregates are observed. In addition, these colloidal arrangements are used for development of molecularly imprinted polymer (MIP) sensors with highly improved sensing properties. Using PDMS replicas, three hemispherical poly(methacrylic acid-ethylene glycol dimethacrylate) (poly(MAA-EGDMA)) MIP films, including planar MIP and non-imprinted polymer (NIP) films, are photopolymerized for detection of trace atrazine in an aqueous solution. From gravimetric quartz crystal microbalance (QCM) measurements, a non-close-packed MIP film exhibits highest sensing response (Δf = 932 Hz) to atrazine detection among hemispherical MIP films and shows 6.5-fold higher sensing response than the planar MIP film. In addition, the sensitivity of the MIP sensor is equivalent to -119 Hz/(mol L(-1)). From the ratio of slopes of the calibration curves for the hemispherical MIP and NIP films, the imprinting factor (If) is as high as 11.0. The hemispherical MIP film also shows excellent selectivity in comparison with the sensing responses of other analogous herbicides. As a result, this molecular surface imprinting using PS colloidal arrays is highly efficient for herbicide detection.

TiO₂ nanoparticles functionalized monolithic capillary microextraction online coupled with inductively coupled plasma mass spectrometry for the analysis of Gd ion and Gd-based contrast agents in human urine.

In this work, a novel method of TiO2 nanoparticles (NPs) functionalized monolithic capillary microextraction (CME) online coupling with inductively coupled plasma mass spectrometry (ICPMS) was developed for the sequential determination of Gd(3+) and Gd-based contrast agents in human urine samples. The monolithic capillary was prepared by embedding anatase TiO2 NPS in the poly(methacrylic acid-ethylene glycol dimethacrylate) (MAA-EDMA) framework. The Gd(3+) and Gd-based contrast agents (such as gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) and Gd-DTPA-bismethylamide (Gd-DTPA-BMA)) display different adsorption behaviors on the prepared monolithic capillary which possesses the adsorption properties of both anatase TiO2 NPS and poly(MAA-EDMA) monolith. Under the optimized conditions, the limits of detection (LODs) were found to be 3.6, 3.2, and 4.5 ng L(-1) for Gd(3+), Gd-DTPA, and Gd-DTPA-BMA, respectively, which are the lowest up to date. The enrichment factor was 25-fold with the sample throughput of 5 h(-1). The proposed method was validated by the analysis of Gd(3+) and Gd-DTPA in the healthy human urine samples as well as Gd(3+) and Gd-DTPA-BMA in patient urine samples. It was found that only a small amount of the free Gd(3+) was released from Gd-DTPA-BMA, and accurate results could be obtained since no oxidation/reduction or subtraction is involved in this method. This method is simple, sensitive, and rapid and provides a very attractive nonchromatography strategy for the speciation of Gd(3+) and Gd-based contrast agents in urine samples.

The development of methacrylic acid based monolithic discs used in the microfluidic chips for application in the determination of catecholamines

A solid phase extraction (SPE) based monolithic disc integrated microchip was developed for purposes of detection or qualitative determination of basic catecholamines: epinephrine (E), norepinephrine (NE) and dopamine (DA). The method is based on the use of a weak cation-exchange porous monolith, prepared in situ in the chamber of the boro-float microchip via photoinitiated polymerization to form desired poly(methacrylic acid-ethylene glycol dimethacrylate) [poly(MA-EGDMA)] monolithic phase which served as a SPE matrix. A surface area of 29.45m2g−1 was measured for the monolithic SPE material, obtained by using BET (Brunauer–Emmett–Teller) method. Adsorption of the catecholamines on SPE monolith was achieved using 20mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), buffered at pH 7 to protonate analytes while desorption was performed with 100mM phosphate, buffered at pH 3 to protonate the carboxylate groups of the monolithic phase which releases the analytes. The effects of the two sample injection methods (electrokinetic and pressure) on adsorption using cation-exchange based monolithic disc were examined. The detection of catecholamines was achieved on the separation channel of the microchip during the elution step via a laser-induced native fluorescence (LINF) measurement without any expensive and time consuming labelling processes. Different buffer combinations were used to establish a good correlation between native fluorescence intensity and high elution ratio of the catecholamines. The applicability of this approach to standard catecholamine solutions promises a potential for future investigations such as catecholamine separation and detection in actual samples.

Development of a solid‐phase microextraction fiber coated with poly(methacrylic acid‐ethylene glycol dimethacrylate) and its application for the determination of chlorophenols in water coupled with GC

A solid-phase microextraction (SPME) fiber coated with poly(methacrylic acid-ethylene glycol dimethacrylate) coupled to GC with a micro electron-capture detector was developed for the determination of four chlorphenols in water samples for the first time. A novel and simple method for the preparation of this novel SPME fiber was proposed by copolymerization of methacrylic acid and ethylene glycol dimethacrylate in an appropriate solvent using a glass capillary as a "mold". The factors affecting the polymerization were optimized in detail. Furthermore, the extraction performance of the poly(methacrylic acid-ethylene glycol dimethacrylate) fiber was evaluated. Moreover, experimental headspace-SPME parameters, such as extraction temperature, extraction time, salt concentration, stirring speed, and pH, were optimized by orthogonal array experimental designs. Under the optimized conditions, the target analytes were linear in the range of 0.2-50 ng/mL, and the correlation coefficients were all greater than 0.99. RSD was less than 8.9%, and the detection limits were in the range of 0.1-10 ng/L. Four cholorphenols were detected from tap and lake water samples using the proposed method, with the recoveries of spiked natural water samples were ranged from 91.8 to 110.8, and 90.6 to 111.4% for tap and lake water samples, respectively.

A novel solid‐phase extraction–spectrofluorimetric method for the direct determination of atenolol in human urine

A novel, simple, sensitive and selective solid-phase extraction (SPE)-spectrofluorimetric method has been developed for the determination of atenolol (ATE) in human urine. Because an extraction procedure is required to isolate ATE or eliminate the interfering molecules present in complex human urine for the direct spectrofluorimetric determination, a pH-sensitive poly(acrylic acid-ethylene glycol dimethacrylate) [poly(AA-EGDMA)] hydrogel was developed and used as a SPE adsorbent. Some factors affecting the ATE extraction efficiency, such as washing solvent type and volume, and the volume of elution solvent were optimized. Eluates from SPE cartridges were analyzed using a spectrofluorimeter (λ(ex) = 277 nm and λ(em) = 300 nm). The calibration graph was linear over the concentration range 0.15-4.0 µg/mL. Limit of detection (LOD) and limit of quantification (LOQ) values were found to be 0.03 and 0.10 µg/mL, respectively. Relatively high intraday [2.06%, mean relative standard deviation (RSD)] and interday (2.6%, mean RSD) precisions were achieved. High mean recovery (95.4%) and low RSD values (3.8%) were obtained for spiked ATE in human urine. The spectrofluorimetric method presented here can be easily applied to assay trace amounts of ATE in pharmaceuticals and biological samples.

Hydrogel Containing Silica Shell Cross-Linked Micelles for Ocular Drug Delivery

Poly(2-hydroxyethyl methacrylate-methacrylic acid-ethylene glycol dimethacrylate) hydrogels loaded with silica shell cross-linked methoxy(polyethylene glycol)-block-polycaprolactone (MePEG-b-PCL) micelles with rod-like morphology were prepared as a potential soft contact lens material for the sustained release of ocular drugs. The silica shell cross-linked methoxy micelles (SSCMs) comprising a polycaprolactone core surrounded by a silica shell were synthesized and their size, morphology, stability, and drug release kinetics were evaluated. The relationships between the composition of the SSCM-loaded poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogels and their transparency, surface wettability, and equilibrium water content were determined. Scanning electron microscopy (SEM) images of SSCM-hydrogel systems showed the presence of intact SSCMs within the hydrogel matrix. Dexamethasone acetate (DMSA), a hydrophobic ophthalmic drug, was loaded into the SSCMs prior to their incorporation into the hydrogels. In vitro release of DMSA from the SSCM-hydrogels, with varying drug loading levels, was observed for up to 30 days. Overall, the incorporation of rod-like SSCMs within pHEMA-based hydrogels provided sustained release over prolonged periods while maintaining optical transparency. This delivery system may be suitable for use as a therapeutic soft contact lens material.

Polymer Monolith Microextraction Coupled with HPLC for Determination of Jasmonates in Wintersweet Flowers

A simple, fast, and effective method has been presented for the determination of jasmonates in plant samples by polymer monolith microextraction (PMME). A poly (methacrylic acid-ethylene glycol dimethacrylate) (MAA-EGDMA) monolith-based device was developed for extraction, purification, and concentration; HPLC-UV was used for evaluation. To realize the best microextraction efficiency, parameters such as sample pH value, flow rate, and sample volume were systematically examined and optimized. Aqueous solution (5 mL) of jasmonates at pH 3.0 was selected as sample solution, and loaded onto the monolith at flow rate of 0.15 mL/min; finally, 50 μL of acetonitrile was used for elution. The proposed method exhibited impressive enrichment efficiency (almost 100-fold) and the limits of detection for jasmonic acid and methyl jasmonate obtained 0.5 and 2 ng/mL by using UV detection. Wide linear ranges were also observed (2–2000 and 5–2000 ng/mL) for both jasmonic acid and methyl jasmonate, with R2 > 0.999. The developed PMME-HPLC method was successfully applied to the determination of jasmonates in fresh wintersweet flowers with recoveries in the range of 91.9–97.2%. The result was confirmed by an HPLC-MS method. The PMME method was also compared with a conventional C18-SPE method and exhibited better clean-up efficiency.