Solid-phase Extraction High-performance Liquid Chromatography Research Articles

Comprehensive undergraduate experiment: determination of phenylurea herbicide in tea by magnetic solid-phase extraction-high performance liquid chromatography

Against the backdrop of the Ministry of Education's promotion of new agricultural science construction and interdisciplinary integration, a comprehensive chemistry experiment to enhance the practical skills of students in preparing biomass functional materials and detecting pesticide residues was designed. Natural loofah was utilized as a precursor in synthesizing nitrogen-doped magnetic porous carbon materials, which were then applied in a magnetic solid-phase extraction (MSPE) technique. Subsequently, high performance liquid chromatography (HPLC) was employed to analyze and detect the phenylurea herbicide monuron in tea. The experimental process included material synthesis, characterization, optimization of the MSPE conditions, adsorption performance studies, and HPLC, reflecting its scientific, systematic nature and providing a comprehensive learning platform for students. It not only deepens student understanding of the relationship between material characterization and application, but also improves their experimental design and problem-solving capacities. Moreover, by integrating cutting-edge science, ideological and political education, and experimental training, it not only stimulates student interest in scientific research and cultivates innovative thinking and practical skills, but also strengthens their feelings of social responsibility and historical mission. This approach realizes the comprehensive educational goals of experimental training and lays the foundation for nurturing high-quality talent with a global perspective and sense of social responsibility.

Structure-based design and screening of hydrogel copolymer/Fe3O4 composite microspheres for magnetic solid phase extraction of bisphenol A from aqueous samples

It is of great significance to monitor bisphenol A (BPA) in the environment because of its potential environmental and health risks. However, the detection of trace or ultratrace BPA in complicated environmental samples is challenging due to the relatively low affinity and poor selectivity of existing adsorbents used in sample pretreatment. Herein, we report a high-affinity, low environment-dependent and strong interference-resistant abiotic affinity ligand, a N-methacryloyl-l-lysine-NH2 (MLys)-based hydrogel copolymer (HP 17) screened from a small focused polymer library engineered by incorporating various combinations and ratios of candidate functional monomers. The selection of these monomers was guided by molecular mechanism between BPA and the ligand-binding pocket of its estrogen receptors. The BPA–HP17 binding is mainly a synergistic effect of π-cation and hydrophobic interactions. The screened HP 17 has high adsorption capacity (349.4 mg/g) for BPA under wide pH (3.0–10.0) and ionic strength (0–150 mM) range. To improve its practicability, a hydrogel copolymer/Fe3O4 composite microspheres (Fe3O4@HP 17) was synthesized and applied for magnetic solid phase extraction–high-performance liquid chromatography (MSPE–HPLC) analysis of BPA in tap water, lake water and industrial effluents. The method shows wide linear range (2.5⁓100 ng/mL), high sensitivity (detection limit of 0.22 ng/mL even without further concentration after desorption), high accuracies (92.6⁓103.0 %) and good precisions (0.57⁓4.53 %), indicating a great potential of this material and method in the detection of trace or ultratrace BPA in complex environmental water samples.

Development of a Quality Evaluation Method for Allii Macrostemonis Bulbus Based on Solid-Phase Extraction–High-Performance Liquid Chromatography–Evaporative Light Scattering Detection Chromatographic Fingerprinting, Chemometrics, and Quantitative Analysis of Multi-Components via a Single-Marker Method

As a traditional Chinese medicine (TCM), Allii Macrostemonis Bulbus (AMB) is a key herb for the treatment of thoracic paralytic cardiac pain, but its quality evaluation method has not yet been fully clarified. In this study, chromatographic fingerprints of AMB were developed using solid-phase extraction–high-performance liquid chromatography–evaporative light scattering detection (SPE-HPLC-ELSD) to evaluate the quality of AMB from various origins and processing methods. This was achieved by employing chemical pattern recognition techniques and verifying the feasibility and applicability of the quality evaluation of AMB through the quantitative analysis of multi-components via a single-marker (QAMS) method. Through the analysis of the fingerprints of 18 batches of AMB, 30 common peaks were screened, and 6 components (adenosine, syringin, macrostemonoside T, macrostemonoside A, macrostemonoside U, and macrostemonoside V) were identified. Moreover, three differential markers (macrostemonoside A, macrostemonoside T, and macrostemonoside U) were screened out using chemometrics techniques, including principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminant analysis (OPLS-DA). Subsequently, a QAMS method was established for macrostemonoside T and macrostemonoside U using macrostemonoside A as an internal reference. The results demonstrate the method’s accuracy, reproducibility, and stability, rendering it suitable for the quality evaluation of AMB. This study provides a theoretical basis for drug quality control and the discovery of quality markers for AMB.

Poly[1-vinyl-3-benzyltriethylammonium proline ionic liquid] membrane: Preparation, properties and adsorption applications

A novel poly[1-vinyl-3-benzyltriethylammonium proline ionic liquid] membrane(PIL/PVDF membrane) were prepared through the blending poly[1-vinyl-3-benzyltriethylammonium proline ionic liquid](P[Pro][TEA])-poly(vinylidene fluoride)(PVDF) phase inversion method. A series of PIL/PVDF membrane characterization (NMR, FT-IR, SEM, EDS, and XPS) was performed. The properties of PIL/PVDF membrane (contact angle, water flux, mechanical properties, thermal stability,electric charge property, specific surface area and pore diameter) were evaluated. A solid phase extraction − high performance liquid chromatography (SPE-HPLC) method for separation/analysis of quercetin was developed. The factors affecting the adsorption and elution (time, dosage, pH etc.) were investigated. Under optimal conditions, the method has been successfully applied to the separation/analysis of quercetin in tea, and the recovery rates are satisfactory (86.4–106.0 %). The concentration factor of quercetin was 10. The adsorption capacity of PIL/PVDF membrane towards quercetin was 22.1 mg g−1. The extraction mechanism was preliminarily discussed. The established SPE-HPLC method was simple and reliable, which provided application prospects for extraction and detection of quercetin.

Preparation of magnetic molybdenum disulfide for the extraction of neonicotinoid insecticides from environmental water samples

In this study, magnetic molybdenum disulfide hybrid composites (Fe3O4/MoS2) were successfully synthesized by in situ fabrication method and firstly applied as magnetic adsorbent for extracting neonicotinoid insecticides from environmental water samples. The Fe3O4/MoS2 composites were characterized in detail by scanning electron microscope, fourier transform infrared, X-ray diffraction and vibrating sample magnetometer, and possessed the faster adsorption capacity towards neonicotinoid insecticides (only 10 min). The parameters (solution pH, amounts of adsorbents, adsorption time, elution conditions and sample volume) effecting the performance of magnetic solid-phase extraction were carefully investigated. Under the optimal conditions, the magnetic solid-phase extraction-high performance liquid chromatography method based on Fe3O4/MoS2 composites for enriching and detecting neonicotinoid insecticides in environmental water samples was established. The good linearity (0.01–10 μg/mL) with correlation coefficients between 0.9949 and 0.9999 was obtained. The limits of detection and the limits of quantifications were 0.48–0.67 ng/mL and 1.44–2.02 ng/mL, respectively. With spiked at three different concentration levels (50, 100,500 ng/mL), the recovery was 66.0–91.3 % with relative standard deviations from 1.4 % to 8.3 %. These data demonstrated that the developed method was highly sensitive, repeatable and easily operated. Also, this study provided new adsorbents for other trace pollutants in the environment.

Analysis of parabens in environmental water samples by covalent organic framework-based magnetic solid-phase extraction-high performance liquid chromatography

Parabens are a class of antimicrobial preservatives that are widely used in cosmetics, pharmaceuticals, and food products because of their ease of production, antimicrobial effect, and low price. The widespread use of these parabens, poses potential risks to human health. Therefore, it is necessary to establish a simple and rapid method for the detection of parabens. The large number of substrate interferences in complex samples is an important factor affecting the sensitivity of analytical methods. Magnetic solid-phase extraction (MSPE) has received much attention because of its advantages of easy operation, short extraction time, small sample amount, low cost, and environmental friendliness. Covalent organic frameworks (COFs) with high crystallinity, high specific surface area, adjustable pore size, regular porosity, as well as high chemical and thermal stability are now widely used in separation and analysis. Therefore, a sample pretreatment method combining MSPE and COF for the analysis of parabens in complex matrices is very promising. A magnetic covalent organic framework, Fe3O4@TbBd, was successfully synthesized by the Schiff base reaction of 1,3,5-triformylbenzene (Tb) and benzidine (Bd) at room temperature using Fe3O4 nanoparticles as magnetic cores. Characterization by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) measurements, etc. revealed that the magnetic COF has high magnetic responsiveness, as well as good thermal and chemical stability, which make it an ideal adsorbent for the MSPE of parabens. Some factors related to the extraction efficiency, including the amount of adsorbent, extraction time, pH, desorption solvent, desorption time, and number of desorption were systematically investigated. A method involving MSPE and high performance liquid chromatography-ultraviolet detection (HPLC-UV) based on the Fe3O4@TbBd was developed for the determination of four parabens (ethylparaben, propylparaben, butylparaben, and benzylparaben) in environmental water samples. Under the optimal extraction conditions, the method showed good linearities. The limits of detection and limits of quantification were 0.2-0.4 μg/L and 0.7-1.4 μg/L for the four analytes, respectively. The recoveries at three spiked levels were in the range of 86.1%-110.8% with intra-day and inter-day RSDs of less than 5.5% and 4.9%, respectively. The method was successfully applied to the determination of parabens in East Lake water, Yangtze water, and domestic wastewater. Ethyl paraben and propyl paraben were detected in domestic wastewater at the levels of 1.8 μg/L and 0.4 μg/L, respectively. The recoveries of the parabens at different spiked levels ranged from 80.7% to 117.5%, with RSDs of 0.2%-8.8%. The method has good potential for the determination of parabens in environmental water samples because of its operational simplicity, short extraction time, high sensitivity, and environmental friendliness.

Simultaneous determination of four antibiotics in human urine and hair samples employing a simple and efficient dispersive micro solid-phase extraction-high performance liquid chromatography.

Antibiotics containing azithromycin, amoxicillin, doxycycline, tetracycline, and azithromycin are widely utilized in the treatment of bacterial infections, and their determination in biological samples is critical to evaluate their side effects. A dispersive micro solid-phase extraction (DMSPE) as an efficient sample preparation was developed for the simultaneous extraction of the antibiotics in biological samples. For this purpose, chitosan@Fe3O4 nanoparticles were prepared as a green and magnetic sorbent based on a chemical coating of Fe3O4 nanoparticles with chitosan. The sorbent was compared with several sorbents such as ZnO NPs, CuO NPs, and Fe3O4 NPs to extract the antibiotics. In addition, effective factors for antibiotic extraction were evaluated and optimized using a central composite design and one factor at a time. The method has wide linearity in the concentration ranges of 2.1-800.0, 3.5-1000.0, 2.0-800.0, and 2.7-1000.0μgL-1 with an R-squared higher than 0.9958 for the determination of azithromycin, amoxicillin, doxycycline, and tetracycline, respectively. The limit of detection and limit of quantitation was lower than 1.1 and 3.5μgL-1, respectively. The relative standard deviations (RSDs) were also lower than 4.90% for the determination of the analytes at a concentration of 20.0µgL-1. High recoveries in the percentage range of 94.70-106.75%, with RSDs between 4.64 and 5.83%, were obtained to analyze spiked urine and hair samples. The DMSPE-HPLC-DAD procedure displayed various advantages for determining antibiotics, including simple operation, high recoveries, low sample solution and desorption solvent consumption, high preconcentration factors, proper determination time, and simple and inexpensive method of sorbent preparation.

Simultaneous Determination of Protoberberine Alkaloids Derived from Coptidis Rhizoma and Phellodendri Cortex in Pharmaceuticals by On-line Solid-Phase Extraction (SPE)—High Performance Liquid Chromatography with Ultraviolet Detection (HPLC-UV)

An automated on-line solid-phase extraction (SPE) high-performance liquid chromatography (HPLC) method was developed for the determination of six protoberberine alkaloids in compound Chinese medicines containing Coptidis Rhizoma and Phellodendri Cortex. The sample solution extracted by acidic-methanol was loaded into the constructed system directly to perform enrichment and the purification of the analytes was performed automatically. A cation-exchanged sorbent based on turbulent chromatography was employed for on-line SPE to remove macro and neutral matrix interferences from samples. The target alkaloids were retained on the SPE column and eluted onto the trapping C18 column by a mobile phase of methanol/500 mM ammonium acetate (85:15) at a flow rate of 0.3 mL/min. Ion pair reverse phase high-performance liquid chromatography was employed to complete the determination of six analytes. The results showed the linear correlation coefficients for all analytes were above 0.999. The peak area of relative standard deviation in reproducibility measurements were from 0.55% to 2.39%. Recovery measurements spiked at two levels were from 92.71% to 104.28%. The reported method was suitable for the determination of six active alkaloids in multicomponent Chinese medicines containing Coptidis rhizoma and Phellodendri cortex.

Simultaneous determination of raloxifene and tamoxifen using dispersive micro solid-phase extraction and HPLC method in real water, human hair and serum samples

ABSTRACT A sensitive determination procedure was presented for two anticancer drugs (tamoxifen and raloxifene) in real water and biological samples based on magnetic dispersive micro solid-phase extraction–high-performance liquid chromatography with an ultraviolet detector. Fe3O4 NPs@SiO2@TiO2 nanocomposite was synthesised as a magnetic sorbent by the sol-gel technique. The effective parameters in the procedure were optimised with an experimental design, including screening and optimisation steps. Under the optimum determination conditions, the procedure displayed wide linear ranges of 5.3–735.0 and 7.0–806.0 ng mL−1 with R-squared of 0.9916 and 0.9908, limit of detections of 1.6 and 2.1 ng mL−1 for the raloxifene and tamoxifen determination, respectively. The intra-day relative standard deviations were 3.76 and 3.59% for three times the raloxifene and tamoxifen measurements, respectively. The preconcentration factors for the raloxifene and tamoxifen determination with a concentration of 20 ng mL−1 were 506.1 and 546.7, respectively. The method was applied to analyse well water, tap water, and hair samples and determine raloxifene and tamoxifen simultaneously with recoveries between 88.5–96.4 and relative standard deviations lower than 8.4%. The method’s advantages for raloxifene and tamoxifen measurement included easy operation, low sorbent and desorption solvent consumption, simple sorbent preparation and separation, and suitable analysis time.

Distribution and Ecological Risk Assessment of Pharmaceuticals and Personal Care Products in Sediments of North Canal, China

The pollution of water bodies by pharmaceuticals and personal care products (PPCPs) has attracted widespread concern due to their widespread use and pseudo-persistence, but their effects on sediments are less known. In this study, solid-phase extraction-high performance liquid chromatography–tandem mass spectrometry (SPE-LC/MSMS) was used to investigate the occurrence and ecological risks of five typical pharmaceuticals and personal care products (PPCPs) in thirteen key reservoirs, sluices, dams, and estuaries in the Haihe River Basin. At the same time, the PPCP exchanges of surface water, groundwater, and sediments in three typical sections were studied. Finally, the PPCP’s environmental risk is evaluated through the environmental risk quotient. The results showed that the five PPCPs were tri-methoprazine (TMP), sinolamine (SMX), ibuprofen (IBU), triclosan (TCS), and caffeine (CAF). The average concentration of these PPCPs ranged from 0 to 481.19 μg/kg, with relatively high concentrations of TCS and CAF. The relationship between PPCPs in the surface sediments was analyzed to reveal correlations between SMX and TMP, CAF and IBU, CAF and TCS. The risk quotients (RQ) method was used to evaluate the ecological risk of the five detected PPCPs. The major contributors of potential environmental risks were IBU, TCS and CAF, among which all the potential environmental risks at the TCS samples were high risk. This study supplemented the research on the ecological risk of PPCPs in sediments of important reaches of the North Canal to reveal the importance of PPCP control in the North Canal and provided a scientific basis for pollution control and risk prevention of PPCPs.

Adsorption characteristics of polythiophene for tetracyclines and determination of tetracyclines in fish and chicken manure by solid phase extraction-HPLC method

Porous polythiophene materials were successfully synthesized by external-crosslinker method and applied as sorbents in solid-phase extraction. A method for the determination of tetracycline antibiotics (tetracycline/ oxytetracycline/doxycycline) in fish and chicken manure was proposed by combining solid phase extraction-ultraviolet visible spectrophotometer (SPE-UV) and solid phase extraction-high performance liquid chromatography (SPE-HPLC). The effects of material dosage, extraction time, washing time, eluent type and dosage, and the reusability of polythiophene sorbent on extraction rate were investigated. With the use of SPE-HPLC method, satisfied linearity for three tetracyclines antibiotics was obtained in the range of 0.004–1 mg/L. The detection limits (LODs) were ranged from 0.0012 to 0.0027 mg/L and the relative standard deviations (RSDs) were 3.5–7.3% (n = 5). The recoveries in actual fish samples and chicken manure samples were 91.1–114.1% and 69.5–93.2%, respectively. No tetracycline antibiotics were detected in fish samples and no doxycycline was detected in chicken manure samples. However, oxytetracycline and tetracycline were detected in two chicken manure samples with the contents of 5.12, 6.58 mg/kg and 6.08, 7.72 mg/kg, respectively. This method was simple, sensitive and suitable for the determination of tetracyclines in practical samples.

A Novel Multi-purpose MIP for SPE-HPLC and QCM Detection of Carbaryl Residues in Foods

In this work, two detection methods of solid-phase extraction–high-performance liquid chromatography (SPE-HPLC) and quartz crystal microbalance (QCM) were established, based on a surface molecularly imprinted polymer material (MIP). The material can be used as a selective solid-phase extraction filler and as a coating for sensitive quartz crystal microbalances by virtue of the polyhydroxy structure of grafted silicon spheres together with the network structure from cross-linked polymerization. The adsorption properties of the prepared MIP were analysed by dynamic and static adsorption tests, and the experimental conditions for SPE-HPLC and QCM analysis were optimized. Under the optimal conditions, the linear range of MIP-SPE-HPLC for the detection of carbaryl was 0.5–60 μg L−1 (R2 = 0.99913), and the detection limit was 0.0573 μg L−1. The proposed QCM sensor displayed a linear relationship between the frequency shift and the concentration of carbaryl ranging from 5 to 80 μg L−1 with a low detection limit of 0.6845 μg L−1 (signal-to-noise ratio, S/N = 3). Through a series of experiments, it was shown that the prepared MIP has good adsorption and selectivity for carbaryl, and the MIP-based HPLC and QCM sensor can be applied to the detection of actual food samples.

Electrospinning fabrication of covalent organic framework composite nanofibers for pipette tip solid phase extraction of tetracycline antibiotics in grass carp and duck

In the current study, a novel covalent organic frameworks COF-SCU1 incorporated electrospun nanofibers (PAN@COF-SCU1 nanofibers) was fabricated via a facile electrospinning method and utilized as adsorbent in pipette tip solid-phase extraction (PT-SPE) of tetracycline antibiotics (TCs) from foods. The prepared PAN@COF-SCU1 nanofibers possessed both of the unique characteristics of electrospun nanofibers and COFS-CU1, and thus improving the adsorption capacity of the electrospun nanofibers and preventing the problems of leakage and high pressure caused by directly using the nanosize COFs as adsorbent in PT-SPE. The experiments affected the adsorption and desorption efficiencies, such as the loading ratios of COFS-CU1 in nanofibers, the amount of nanofibers, the matrix pH and desorption solvent, were studied in detail. Eventually, a new pipette tip solid-phase extraction-high performance liquid chromatography (PT-SPE/HPLC) method was proposed for the analysis of three TCs from food. Satisfied linearity for TCs was obtained in the range of 4–70 ng mL−1. The limits of detection and quantification were ranged from 0.6 to 3 ng mL−1 and from 2 to 10 ng mL−1, respectively. The interday and intraday precisions (RSD) were all lower than 9%. The proposed PT-SPE/HPLC method was used to determine TCs residues in grass carp and duck samples for the first time. The results could not only explore the availability of PT-SPE in the extraction of TCs in food samples, but also broadened the potential applications of COFs in sample preparation.

Distribution of Four Artificial Sweeteners in Water Treatment and Water Supply System in City H of Zhejiang Province

Taking the sewage and drinking water treatment system of two cities in Zhejiang Province as the main research target, a systematic investigation on the common artificial sweeteners was carried out by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The results showed that SPE-HPLC can accurately determine micro acesulfame (ACE), saccharin (SAC), aspartame (ASP), and neotame (NEO) in water. The detection limits were 57, 120, 170, and 47 μg·L-1, and the quantification limits were 190, 400, 567, and 157 μg·L-1, respectively. After optimization of the solid phase extraction procedure when using PWAX columns, the recoveries of ACE and SAC were enhanced to 86.5% and 97.7%; however, it slightly decreased to 66.5% for NEO. The occurrence rates of ACE, SAC, and NEO in domestic sewage were 100.0%, and it was only 33.3% for ASP. The highest concentrations of four aforementioned artificial sweeteners in domestic sewage were 0.83, 4.52, 1.22, and 7.57 μg·L-1, respectively. The highest concentrations of acesulfame, saccharin, aspartame, and neotame in source water were 22.94, 39.17, 0.73, and 8.92 μg·L-1, respectively, and detection rates were 72.7%, 90.9%, 18.2%, and 90.9%, respectively. Most artificial sweeteners were removed by the prozone process; the removal efficiencies of ACE, SAC, and NEO ranged from 67.7% to 100.0%, and the removal efficiencies of ACE, SAC, and NEO by the advanced treatment process ranged from 73.7% to 100.0%, which effectively reduced the risk of drinking water quality. The four artificial sweeteners were not detected in the water supply network.

Simultaneous Determination of Six Alkaloids in Rat Plasma with On-line SPE–HPLC Using a Homemade Four-Hydrogen Furfuryl-Based Polymer Monolithic Sorbent

A four-hydrogen furfuryl-based polymer monolithic column for solid-phase extraction was prepared via in situ radical polymerization, using tetrahydrofurfuryl methacrylate as the monomer. The monolith was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and nitrogen adsorption–desorption method, showing relatively uniform porous structure with micro-, meso- and macro-pores and a relatively high surface area of 54.99 m2 g−1. Online solid-phase extraction–high-performance liquid chromatography was carried out to quantitatively analyze six alkaloids, including caffeine, hydroxy-α-sanshool, hydroxy-β-sanshool, hydroxy-γ-sanshool, hydroxy-γ-isosanshool and γ-sanshool in rat plasma. The results show that the prepared polymer monolithic sorbent exhibits good clean-up ability for bio-matrix, as well as good extractive ability for the six concerning alkaloids in rat plasma. Method validation shows that the correlation coefficients of the linear regressions are higher than 0.998 and the accuracy represented by spiked recovery ranges in 94.37–100.7%, 99.52–101.1%, 98.93–100.8%, 98.36–101.6%, 99.22–101.2% and 99.86–101.4% for the six alkaloids, respectively, as well as the LOD ranges in 2.10–3.90 ng mL−1 and the LOQ in 6.35–10.14 ng mL−1. Compared to the reference works, the present work is a simple and effective method for online extraction and simultaneous determination of six alkaloids in plasma with high accuracy and low cost.

Pollution characteristics of antibiotics and antibiotic resistance of coliform bacteria in the Yitong River, China.

In this study, the concentrations of nine typical antibiotics, including sulfadiazine (SD), sulfamerazine (SMR), sulfamethazine (SM2), sulfamethoxazole (SMZ), ofloxacin (OFX), ciprofloxacin (CIP), trimethoprim (TMP), oxytetracycline (OTC), and tetracycline hydrochloride (TC), were detected in the Yitong River by solid-phase extraction high-performance liquid chromatography. The concentrations of the antibiotics were analyzed. Additionally, an improved immobilized substrate enzyme substrate method (DST-enzyme substrate method) was developed and used to evaluate the antibiotic resistance of coliform bacteria to OFX, CIP, enrofloxacin (ENR), TC, sulfisoxazole (SOX), and TMP in the Yitong River. The results showed that the concentrations of the nine antibiotics ranged from nd (not detected) to 1.361 μg/L. The detection rate and concentration of OFX were the highest, followed by CIP, and the detection rate and concentration of SM2 and OTC were the lowest. The detection rate and concentrations of antibiotics were higher in August and November than those in May. The antibiotics were mainly distributed in the livestock sewage discharge and suburban domestic sewage discharge areas. Moreover, the drug resistance of total coliform bacteria to fluoroquinolones, sulfonamides, tetracyclines, and TMP varied with season.

ANALYSIS OF FERULIC ACID IN ARABICA COFFEE BEAN (COFFEA ARABICA L.) USING SOLID PHASE EXTRACTION–HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Objective: The purpose of this research is quantitatively analyzing of ferulic acid in the Arabica coffee bean extract from three samples with different regions (Garut, Pangalengan, Tasikmalaya, West Java Indonesia) using Solid Phase Extraction-High Performance Liquid Chromatography (SPE-HPLC) method which is validated.
 Methods: The analysis method used reversed phase HPLC with an Enduro C 18 G (250 mm × 4.6 mm) column and detector UV 312 nm, with a mobile phase of methanol and water containing 1% (v/v) of acetic acid (42:58) at a flow rate of 1.0 ml/min and validation method was examined in linearity, Limit of Detection (LOD), Limit of Quantification (LOQ), precision, and accuracy.
 Results: The results showed that the precision of retention was 8.853 min, correlation coefficient (R) was 0.9996, and the recovery was 96.909%. The quantitative analysis of ferulic acid content in the extract of coffee from thus samples of three different regions were 0.0385%, 0.0169% and 0.0076%, respectively.
 Conclusion: The analytical method was meet the validation criteria. Ferulic acid levels results from the extraction of the digestion process and pretreatment methods of Solid Phase Extraction (SPE) is 0.0385% from Garut area, 0.0169% from Pangalengan area and 0.0076% from Tasikmalaya area.

Chronic pesticide mixture exposure including paraquat and respiratory outcomes among Colombian farmers.

This study explored the potential association between chronic exposure to pesticide mixtures including paraquat and respiratory outcomes among Colombian farmers. Sociodemographic and occupational data, respiratory symptoms and spirometric data were collected. Paraquat in spot urine samples were quantified with solid-phase extraction high-performance liquid chromatography. Multiple Poisson regressions with robust variance were used to determine factors associated with respiratory outcomes. Profiles of pesticide mixtures used were identified among 217 farmworkers, but profenofos and methamidophos-based mixtures were more frequent. Chronic paraquat exposure was slightly associated with self-reported asthma (PR: 1.06; 95% CI 1.00 to 1.13). Different pesticide mixtures were associated with flu, thoracic pain, allergic rhinitis, and obstructive pattern in spirometry. Although acute exposure to paraquat is low among Colombian farmers participating in the study, associations between respiratory outcomes and chronic pesticide mixtures exposure including profenofos, methamidophos or glyphosate require further specific studies.

Magnetically Modified Porous β-Cyclodextrin Polymers for Dispersive Solid-Phase Extraction High-Performance Liquid Chromatography Analysis of Sudan Dyes

Two types of magnetically modified porous β-cyclodextrin polymers (PCDPs) were successfully synthesized. The first type, named MPCDPs(C), was fabricated by co-precipitating PCDPs with Fe3O4, resulting in a Brunauer–Emmett–Teller (BET) surface area of 106.68 m2 g−1. The second type, named MPCDPs(M), was fabricated by grafting PCDPs onto the surface of magnetic microspheres, resulting in a BET surface area of 34.63 m2 g−1. Both MPCDPs were found to enable effective extraction and separation of Sudan dyes from foodstuffs and environmental water. Coupled with high-performance liquid chromatography, the limits of detection for Sudan dyes were in the range of 0.013–0.054 ng mL−1 with MPCDPs(C), and 0.028–0.039 ng mL−1 with MPCDPs(M). Recoveries were between 85.8 and 102.8% for spiked food samples and 88.3 and 103.2% for spiked water samples, suggesting that the developed methods are promising for accurate quantification of Sudan dyes at trace levels in foodstuffs and environmental water.

Simultaneous determination of four azo dyes in paprika powder by high performance liquid chromatography using a porous aromatic framework as the solid-phase extraction sorbent

In this study, a solid-phase extraction-high performance liquid chromatography (SPE-HPLC) method was developed for the determination of Para Red, Orange Ⅱ sodium salt, Sudan Ⅰ, and Sudan Ⅱ in paprika powder based on a self-made porous aromatic framework-6 (PAF-6) solid-phase extraction cartridge. The major factors affecting the extraction efficiency and adsorption capacity of this solid-phase extraction were evaluated. Under optimized conditions, the limits of detection (LODs) and limits of quantification (LOQs) of the four target analytes ranged from 1.5 to 7.0 μg/L and 5.0 to 22.1 μg/L, respectively. The recoveries were in the range of 76.5-89.8%, and the relative standard deviation (RSD) was not more than 5.3% (n=6). Moreover, quantum chemistry calculations were performed to investigate the molecular interaction mechanism between the PAF-6 and target analytes. The results indicated that the target molecules could be stably adsorbed onto the PAF-6. The method is accurate, reliable, and sensitive, and can be successfully applied to detect the four azo dyes in paprika powder.