Fast determination of 14 mycotoxins in chestnut by dispersive solid‐phase extraction coupled with ultra high performance liquid chromatography‐tandem mass spectrometry

A dispersive solid‐phase extraction coupled with ultra high performance liquid chromatography with tandem mass spectrometry method was developed and validated for the simultaneous determination of T‐2 toxin, penicillic acid, fumonisins B₁, B₂, and B₃, aflatoxins B₁, B₂, G₁, and G₂, ochratoxin A, deoxynivalenol, 3‐acetyldeoxynivalenol, 15‐acetyldeoxynivalenol, and zearalenone in chestnut samples. The method was used to analyze 136 samples obtained from Shandong province in China. The mycotoxins were extracted using a dispersive solid‐phase extraction method and cleaned using an improved quick, easy, cheap, effective, rugged, and safe approach. The mycotoxins were then detected using a triple‐quadrupole mass spectrometer. The limits of detection and quantification ranged from 0.02 to 1 and 0.1 to 2 μg/kg, respectively. The recovery rates ranged from 74.2 to 109.5%, with relative standard deviations below 15%. A total of 71 samples were contaminated with seven mycotoxins at concentrations ranging from 1.2 to 105.5 μg/kg, with a number of samples exceeding the maximum limits set in the European regulations for mycotoxins in unprocessed chestnuts.     

分散固相萃取-高效液相色谱法快速测定果蔬中的6种保鲜剂残留量

建立了采用分散固相萃取-高效液相色谱同时测定果蔬中2,4-滴、噻苯咪唑、乙萘酚、邻苯基苯酚、二苯醚和联苯6种保鲜剂残留量的方法。样品经乙腈提取(同时加入氯化钠和无水硫酸镁),提取液经酸性氧化铝分散固相萃取净化,采用Agilent TC C18色谱柱(250 mm×4.6 mm, 5 μm),以甲醇-0.02 mol/L的磷酸二氢钾溶液(pH 6)作为流动相,流速1.0 mL/min,梯度洗脱,用紫外检测器检测,检测波长为235 nm,外标法峰面积定量。6种保鲜剂在0.5～20 mg/L范围内线性关系良好,相关系数均大于0.99; 6种保鲜剂在样品中添加1、2和10 mg/kg 3个浓度水平的回收率为84.2%～99.1% (n=6),相对标准偏差为1.67%～10.3%;方法的定量限为1 mg/kg。该法简便、准确,适用于果蔬中6种保鲜剂残留量的检测。     

Application of a dispersive solid‐phase extraction method using an amino‐based silica‐coated nanomagnetic sorbent for the trace quantification of chlorophenoxyacetic acids in water samples

Herein, an amino‐based silica‐coated nanomagnetic sorbent was applied for the effective extraction of two chlorophenoxyacetic acids (2‐methyl‐4‐chlorophenoxyacetic acid and 2,4‐dichlorophenoxyacetic acid) from various water samples. The sorbent was successfully synthesized and subsequently characterized by scanning electron microscopy, X‐ray diffraction, and Fourier‐transform infrared spectroscopy. The analytes were extracted by the sorbent mainly through ionic interactions. Once the extraction of analytes was completed, they were desorbed from the sorbent and detected by high‐performance liquid chromatography with ultraviolet detection. A number of factors affecting the extraction and desorption of the analytes were investigated in detail and the optimum conditions were established. Under the optimum conditions, the calibration curves were linear over the concentration range of 1–250, and based on a signal‐to‐noise ratio of 3, the method detection limits were determined to be 0.5 μg/L for both analytes. Additionally, a preconcentration factor of 314 was achieved for the analytes. The average relative recoveries obtained from the fortified water samples varied in the range of 91–108% with relative standard deviations of 2.9–8.3%. Finally, the method was determined to be robust and effective for environmental water analysis.     

Detection of 13 mycotoxins in feed using modified QuEChERS with dispersive magnetic materials and UHPLC–MS/MS

An analytical method for the simultaneous determination of 13 mycotoxins in feed by magnetic dispersive solid‐phase extraction combined with ultra‐high performance liquid chromatography and tandem mass spectrometry was developed. The samples were extracted with acetonitrile/water (80:20, v/v, containing 3% acetic acid), and separated by centrifugation after salting‐out, and then treated with magnetic adsorbents to remove interferences. The separation of target mycotoxins was performed on an ACQUITY UPLC HSS T3 column using a mobile phase consisting of 1 mmol/L ammonium acetate with 0.1% formic acid and methanol by gradient elution. Good linearities for the 13 mycotoxins were achieved with correlation coefficients over 0.99, and the recoveries of mycotoxins were in the range of 89.3–112.6% at spiking at levels of 5, 20, and 100 μg/kg, with relative standard deviations of 0.9–10.4%. Based on the functional magnetic materials (MDN@Fe₃O₄, PSA@Fe₃O₄, ZrO_2@Fe₃O₄) applied in dispersive solid‐phase extraction, the pretreatment process is more convenient and it is beneficial to reduce the experimental cost by reusing the recycled magnetic materials. It is a simple, rapid, and environmentally friendly analytical method for the determination of mycotoxins in feed.     

An HPLC method for the determination of ethacridine lactate in human urine

An HPLC method was developed and validated for the determination of ethacridine lactate in human urine. Solid-phase extraction cartridges were used to extract urine samples. Separation was carried out on a C(18) column maintained at 30 degrees C with methanol-0.05% sodium dodecylsulfonate (70:30, v/v, pH 3) as mobile phase at a flow rate of 1.0 mL/min. Detection was at UV 272 nm. The calibration curve was linear in the concentration range of 4-4000 ng/mL, with linear correlation coefficient r equal to 0.9998. The limit of detection for the assay was 1.1 ng/mL. The within-day accuracy ranged from 94.8 to 101.6% and precision from 2.3 to 5.4%. The between-day accuracy ranged from 96.8 to 102.6% and precision from 4.0 to 5.3%. The absolute recovery was 95.4-101.2%. Urine samples were stable for at least 15 days if stored in the dark at -20 degrees C. This simple and accurate method allows the sensitive determination of ethacridine lactate in human urine. It was successfully applied to assess the urine level of ethacridine lactate in women received intra-amniotic injection.     

Trace quantification of selected sulfonamides in aqueous media by implementation of a new dispersive solid‐phase extraction method using a nanomagnetic titanium dioxide graphene‐based sorbent and HPLC‐UV

Herein, a new dispersive solid‐phase extraction method using a nano magnetic titanium dioxide graphene‐based sorbent in conjunction with high‐performance liquid chromatography and ultraviolet detection was successfully developed. The method was proved to be simple, sensitive, and highly efficient for the trace quantification of sulfacetamide, sulfathiazole, sulfamethoxazole, and sulfadiazine in relatively large volume of aqueous media. Initially, the nano magnetic titanium dioxide graphene‐based sorbent was successfully synthesized and subsequently characterized by scanning electron microscopy and X‐ray diffraction. Then, the sorbent was used for the sorption and extraction of the selected sulfonamides mainly through π–π stacking hydrophobic interactions. Under the established conditions, the calibration curves were linear over the concentration range of 1–200 μg/L. The limit of quantification (precision of 20%, and accuracy of 80–120%) for the detection of each sulfonamide by the proposed method was 1.0 μg/L. To test the extraction efficiency, the method was applied to various fortified real water samples. The average relative recoveries obtained from the fortified samples varied between 90 and 108% with the relative standard deviations of 5.3–10.7%.     

Magnetic dispersive solid‐phase extraction based on modified magnetic nanoparticles for the detection of cocaine and cocaine metabolites in human urine by high‐performance liquid chromatography–mass spectrometry

An easy‐to‐handle magnetic dispersive solid‐phase extraction procedure was developed for preconcentration and extraction of cocaine and cocaine metabolites in human urine. Divinyl benzene and vinyl pyrrolidone functionalized silanized Fe₃O₄ nanoparticles were synthesized and used as adsorbents in this procedure. Scanning electron microscopy, vibrating sample magnetometry, and infrared spectroscopy were employed to characterize the modified adsorbents. A high‐performance liquid chromatography with mass spectrometry method for determination of cocaine and its metabolites in human urine sample has been developed with pretreatment of the samples by magnetic dispersive solid‐phase extraction. The obtained results demonstrated the higher extraction capacity of the prepared nanoparticles with recoveries between 75.1 to 105.7% and correlation coefficients higher than 0.9971. The limits of detection for the cocaine and cocaine metabolites were 0.09–1.10 ng/mL. The proposed magnetic dispersive solid‐phase extraction method provided a rapid, environmentally friendly and magnetic stuff recyclable approach and it was confirmed that the prepared adsorbents material was a kind of highly effective extraction materials for the trace cocaine and cocaine metabolites analyses in human urine.     

固相萃取/高效液相色谱法测定化妆品中5种抗组胺药物残留

建立了固相萃取/高效液相色谱(SPE/HPLC)测定化妆品中5种抗组胺药物(多西拉敏、曲吡那敏、溴苯那敏、苯海拉明、氯苯沙明)残留的分析方法。试样经三氯乙酸溶液超声提取,PCX柱净化后,以甲醇-磷酸盐缓冲溶液为流动相,经C18柱分离后进行HPLC检测。5种抗组胺药物在5.0～100 mg/L范围内均呈良好的线性关系,线性系数均大于0.999。在5.0、10.0、25.0 mg/kg 3个加标水平下的平均回收率为92%～108%,相对标准偏差(RSD,n=6)为2.1%～4.2%,检出限为0.5～1.0 mg/L。该方法灵敏度高、重现性好、定量准确。     

Trace determination of five triazole fungicide residues in traditional Chinese medicine samples by dispersive solid‐phase extraction combined with ultrasound‐assisted dispersive liquid–liquid microextraction and UHPLC–MS/MS

A novel and reliable method for determination of five triazole fungicide residues (triadimenol, tebuconazole, diniconazole, flutriafol, and hexaconazol) in traditional Chinese medicine samples was developed using dispersive solid‐phase extraction combined with ultrasound‐assisted dispersive liquid–liquid microextraction before ultra‐high performance liquid chromatography with tandem mass spectrometry. The clean up of the extract was conducted using dispersive solid‐phase extraction by directly adding sorbents into the extraction solution, followed by shaking and centrifugation. After that, a mixture of 400 μL trichloromethane (extraction solvent) and 0.5 mL of the above supernatant was injected rapidly into water for the dispersive liquid–liquid microextraction procedure. The factors affecting the extraction efficiency were optimized. Under the optimum conditions, the calibration curves showed good linearity in the range of 2.0–400 (tebuconazole, diniconazole, and hexaconazole) and 4.0–800 ng/g (triadimenol and flutriafol) with the regression coefficients higher than 0.9958. The limit of detection and limit of quantification for the present method were 0.5–1.1 and 1.8–4.0 ng/g, respectively. The recoveries of the target analytes ranged from 80.2 to 103.2%. The proposed method has been successfully applied to the analysis of five triazole fungicides in traditional Chinese medicine samples, and satisfactory results were obtained.     

Alcohol‐based deep eutectic solvent as a carrier of SiO2@Fe3O4 for the development of magnetic dispersive micro‐solid‐phase extraction method: Application for the preconcentration and determination of morin in apple and grape juices,diluted and acidic extract of dried onion and green tea infusion samples

In this study, a hydrophilic deep eutectic solvent was synthesized as a carrier and disperser of magnetic nanoparticles based on ferrofluid and used to develop the dispersive micro‐solid‐phase extraction method. Ethylene glycol/tetramethylammonium chloride deep eutectic solvent and SiO₂@Fe₃O₄ were used to provide the highly stable ferrofluid with strong sorbing properties without any additional stabilizer, which was employed to extract and determine morin in apple and grape juices, diluted and acidic extract of dried onion, and green tea infusion samples. The dispersibility of SiO₂@Fe₃O₄ and prevention of its aggregation in the sample solution were improved using the deep eutectic solvent‐based ferrofluid. Also, it facilitated the fast injection of sorbent into the sample solution that led to an increase of the contact surface between the sorbent and analyte, and reduction of the extraction time and consumption of the sorbent. The important experimental parameters influencing the extraction efficiency of morin were examined. Under the optimal conditions, a linear calibration curve was obtained in the range of 3–500 µg/L with a determination coefficient of 0.9994. The limits of detection and quantification were of 0.91 and 2.98 µg/L, respectively. While an extraction recovery of 97.7% with relative standard deviation of 3.8% (interday) was obtained via three replicated measurements on a 30 µg/L of morin standard solution, the enrichment factor was 39.1. Finally, this method was successfully used to extract and preconcentrate morin in various samples, followed with their determination by high‐performance liquid chromatography with ultraviolet detection.     

Extraction and determination of flavonoids in fruit juices and vegetables using Fe3O4/SiO2 magnetic nanoparticles modified with mixed hemi/ad‐micelle cetyltrimethylammonium bromide and high performance liquid chromatography

Extraction and determination of three flavonoids (morin, quercetin, and kaempferol) were performed by dispersive magnetic solid phase extraction based on mixed hemi/ad‐micelles and high‐performance liquid chromatography with UV detection. The Fe₃O₄/SiO₂ nanoparticles were synthesized and characterized by X‐ray diffraction, FTIR, scanning electron microscopy, and thermogravimetric analysis. Fe₃O₄/SiO₂ nanoparticles coated with mixed hemi/ad‐micelles cetyltrimethyl ammonium bromide was applied as a sorbent and used for extraction of flavonoids. Effective parameters on the extraction recovery such as amount of magnetic nano particles, volume of cetyltrimethyl ammonium bromide solution with specific concentration, pH of sample solution, adsorption equilibrium time, volume of desorption solvent, and desorption times were evaluated and optimized using fractional factorial design and central composite design. Under the optimum condition limit of detection and linearity were 0.83, 2.7–500.0 for morin, 0.18, 0.7–500.0 for quercetin and, 0.37, 1.3–500.0 µg/L for kaempferol. The extraction recovery with relative standard deviation were 97.88, 1.94 for morin, 95.77, 0.80 for quercetin, and 93.35, 1.45 for kaempferol. The proposed method was applied for simultaneous extraction and determination of flavonoids in several fruit juices and vegetable samples.     

Sensitive determination of phenols in environmental water samples with SPE packed with bamboo carbon prior to HPLC

Bamboo carbon, an inexpensive, readily available material, has attracted great attention in recent years because of adsorptive properties. In this paper, the potential of bamboo carbon as a SPE adsorbent for the determination of phenols, was investigated. Phenols are important environmental contaminants that may adversely affect human health. Parameters influencing extraction efficiency, including type of eluent, eluent volume, amount of adsorbent, as well as sample pH, volume, and flow rate were investigated and optimized. The optimized results exhibited excellent linear relationships between peak area and phenol concentrations over the range of 2.0–100 ng/mL, with precision between 2.2–7.2%. The LODs were 0.06–0.4 ng/mL for the eight phenols tested. The proposed method has been successfully applied to the analysis of several real‐world environmental water samples. These results indicate that bamboo carbon may be used as a novel SPE adsorbent for the concentration and determination of phenols in real environmental water samples.     

Dispersive solid‐phase extraction combined with dispersive liquid‐liquid microextraction for simultaneous determination of seven succinate dehydrogenase inhibitor fungicides in watermelon by ultra high performance liquid chromatography with tandem mass spectrometry

In this study, a simple and accurate sample preparation method based on dispersive solid‐phase extraction and dispersive liquid‐liquid microextraction has been developed for the determination of seven novel succinate dehydrogenase inhibitor fungicides (isopyrazam, fluopyram, pydiflumetofen, boscalid, penthiopyrad, fluxapyroxad, and thifluzamide) in watermelon. The watermelon samples were extracted with acetonitrile, cleaned up by dispersive solid‐phase extraction procedure using primary secondary amine, extracted and concentrated by the dispersive liquid‐liquid microextraction procedure with 1,1,2,2‐tetrachloroethane, and then analyzed by ultra high performance liquid chromatography with tandem mass spectrometry. The main experimental factors affecting the performance of dispersive solid‐phase extraction and dispersive liquid‐liquid microextraction procedure on extraction efficiency were investigated. The proposed method had a good linearity in the range of 0.1–100 µg/kg with correlation coefficients (r) of 0.9979–0.9999. The limit of quantification of seven fungicides was 0.1 µg/kg in the method. The fortified recoveries of seven succinate dehydrogenase inhibitor fungicides at three levels ranged from 72.0 to 111.6% with relative standard deviations of 3.4–14.1% (n = 5). The proposed method was successfully used for the rapid determination of seven succinate dehydrogenase inhibitor fungicides in watermelon.     

Magnetic solid‐phase extraction or dispersive liquid–liquid microextraction for pyrethroid determination in environmental samples

The determination of 15 pyrethroids in soil and water samples was carried out by gas chromatography with mass spectrometry. Compounds were extracted from the soil samples (4 g) using solid–liquid extraction and then salting‐out assisted liquid–liquid extraction. The acetonitrile phase obtained (0.8 mL) was used as a dispersant solvent, to which 75 μL of chloroform was added as an extractant solvent, submitting the mixture to dispersive liquid–liquid microextraction. For the analysis of water samples (40 mL), magnetic solid‐phase extraction was performed using nanocomposites of magnetic nanoparticles and multiwalled carbon nanotubes as sorbent material (10 mg). The mixture was shaken for 45 min at room temperature before separation with a magnet and desorption with 3 mL of acetone using ultrasounds for 5 min. The solvent was evaporated and reconstituted with 100 μL acetonitrile before injection. Matrix‐matched calibration is recommended for quantification of soil samples, while water samples can be quantified by standards calibration. The limits of detection were in the range of 0.03–0.5 ng/g (soil) and 0.09–0.24 ng/mL (water), depending on the analyte. The analyzed environmental samples did not contain the studied pyrethroids, at least above the corresponding limits of detection.     

A sensitive dispersive micro solid‐phase extraction coupled with high performance liquid chromatography for determination of three flavonoids in complex matrics by using crab shell as a sorbent

A sensitive dispersive micro solid‐phase extraction coupled with HPLC has been developed for preconcentration and determination of three flavonoids (quercetin, kaempferol, and isorhamnetin) in complex matrix samples. Parameters that affect extraction efficiency have been optimized. The optimal extraction conditions are using 2 μg/mL of crab shell as the sorbent, extraction for 2 min at pH 7, and then eluting with 100 μL of methanol. As a result, the method shows good linearity (R > 0.9994), low LODs (even 0.08 ng/ml) and satisfactory recovery in real honey and rat urine samples. As an eco‐friendly biomaterial, crab shell powder is used as sorbent in pretreatment of flavonoids, and its adsorption mechanism has been investigated for the first time. Compared with the other reported methods, the proposed strategy is time‐saving, eco‐friendly, and highly sensitive using HPLC (even achieving MS grade sensitivity).     

在线固相萃取/高效液相色谱法测定环境水样中的4种痕量邻苯二甲酸酯

建立了一种在线固相萃取/高效液相色谱测定水样中4种痕量邻苯二甲酸酯(邻苯二甲酸甲酯、邻苯二甲酸乙酯、邻苯二甲酸丁酯和邻苯二甲酸(2-乙基)己酯)的新方法.样品由外加泵注入一根固相萃取小柱上进行富集,再将富集柱切换至高效液相色谱系统中,将富集在固相萃取小柱的邻苯二甲酸酯洗脱至分析柱进行分析.在线固相萃取柱为IonPac(...     

Sensitive determination of typical phenols in environmental water samples by magnetic solid‐phase extraction with polyaniline@SiO2@Fe as the adsorbents before HPLC

A novel magnetic core–shell material polyaniline@SiO₂@Fe (PANI@SiO₂@Fe) has been successfully synthesized and investigated as an effective adsorbent for the magnetic solid‐phase extraction of typical endocrine disrupting compounds such as bisphenol A, tetrabromobisphenol A, and 4‐nonylphenol from water samples. The morphology of the as‐prepared PANI@SiO₂@Fe was characterized by transmission electron microscopy and X‐ray diffraction. The main parameters that influenced the enrichment performance such as the kind of eluent, amount of adsorbent, volume of eluent, adsorption time, elution time, ionic strength, pH, concentration of humic acid, and sample volume were investigated. Under the optimal conditions, a good linear relationship was found in the range of 0.05–100 μg/L for bisphenol A, 0.05–300 μg/L for tetrabromobisphenol A, and 0.05–250 μg/L for 4‐nonylphenol, respectively. The correlation coefficients are all above 0.995. The limits of detection were in the range of 0.009–0.04 μg/L, and precisions were under 3.73% (n  = 6). The real water analysis indicated that the spiked recoveries were in the range of 92.9–98.9% (n  = 3). All these results indicated that the developed method was an efficient tool for the analysis of bisphenol A, tetrabromobisphenol A, and 4‐nonylphenol.     

Solid‐phase extraction assisted dispersive liquid–liquid microextraction based on solidification of floating organic droplet to determine sildenafil and its analogues in dietary supplements

A novel analytical method for the simultaneous determination of the concentration of sildenafil and its five analogues in dietary supplements using solid‐phase extraction assisted reversed‐phase dispersive liquid–liquid microextraction based on solidification of floating organic droplet combined with ion‐pairing liquid chromatography with an ultraviolet detector was developed. Parameters that affect extraction efficiency were systematically investigated, including the type of solid‐phase extraction cartridge, pH of the extraction environment, and the type and volume of extraction and dispersive solvent. The method linearity was in the range of 5.0–100 ng/mL for sildenafil, homosildenafil, udenafil, benzylsildenafil, and thiosildenafil and 10–100 ng/mL for acetildenafil. The coefficients of determination were ≥0.996 for all regression curves. The sensitivity values expressed as limit of detection were between 2.5 and 7.5 ng/mL. Furthermore, intraday and interday precisions expressed as relative standard deviations were less than 5.7 and 9.9%, respectively. The proposed method was successfully applied to the analysis of sildenafil and its five analogues in complex dietary supplements.     

Solid‐phase extraction of drugs with cuttlefish bone powder as a sorbent

We investigated cuttlefish bone powder for the solid‐phase extraction of naproxen, ibuprofen, and carbamazepine. The basic principles controlling the extraction are presented to aid in the choice of the nature and quantity of the extracting phase according to the sample matrix and the solute properties, based on the mechanisms of phase retention. Their retention mechanism is based on hydrogen bonding and electrostatic interactions. The results show a significant recovery rate for the three drugs, selectivity, and low cost. The method has successfully reduced the amount of tested pharmaceuticals with recoveries >87% at pH 4.     

Dispersive admicelle solid‐phase extraction based on sodium dodecyl sulfate coated Fe3O4 nanoparticles for the selective adsorption of three alkaloids in Gegen‐Qinlian oral liquid before high‐performance liquid chromatography

A novel dispersive admicelle solid‐phase extraction method based on sodium dodecyl sulfate‐coated Fe₃O₄ nanoparticles was developed for the selective adsorption of berberine, coptisine, and palmatine in Gegen‐Qinlian oral liquid before high‐performance liquid chromatography. Fe₃O₄ nanoparticles were synthesized by a chemical coprecipitation method and characterized by using transmission electron microscopy. Under acidic conditions, the surface of Fe₃O₄ nanoparticles was coated with sodium dodecyl sulfate to form a nano‐sized admicelle magnetic sorbent. Owing to electrostatic interaction, the alkaloids were adsorbed onto the oppositely charged admicelle magnetic nanoparticles. The quick separation of the analyte‐adsorbed nanoparticles from the sample solution was performed by using Nd‐Fe‐B magnet. Best extraction efficiency was achieved under the following conditions: 800 μL Fe₃O₄ nanoparticles suspension (20 mg/mL), 150 μL sodium dodecyl sulfate solution (10 mg/mL), pH 2, and vortexing time 2 min for the extraction of alkaloids from 10 mL of diluted sample. Four hundred microliters of methanol was used to desorb the alkaloids by vortexing for 1 min. Satisfactory extraction recoveries were obtained in the range of 85.9–120.3%, relative standard deviations for intra‐ and interday precisions were less than 6.3 and 10.0%, respectively. Finally, the established method was successfully applied to analyze the alkaloids in two batches of Gegen‐Qinlian oral liquids.