共查询到20条相似文献,搜索用时 15 毫秒
1.
A simple method based on simultaneous microwave-assisted derivatization and ionic liquid-based dispersive liquid-liquid microextraction (IL-based DLLME) is proposed for the derivatization, extraction and preconcentration of formaldehyde in beverage samples prior to the determination by high-performance liquid chromatography (HPLC). Formaldehyde was in situ derivatized with 2,4-dinitrophenylhydrazine (DNPH) and simultaneously extracted and preconcentrated by using microwave-assisted derivatization and IL-based DLLME in a single step. Several experimental parameters, including type and volume of extraction solvent, type and volume of disperser, microwave power and irradiation time, volume of DNPH, pH of sample solution, and ionic strength were evaluated. When the microwave power was 120 W, formaldehyde could be derivatized and extracted simultaneously only within 90 s. Under optimal experimental conditions, good linearity was observed in the range of 0.5-50 ng/mL with the correlation coefficient of 0.9965, and the limit of detection was 0.12 ng/mL. The proposed method was applied to the analysis of different beverage samples, and the recoveries of formaldehyde obtained were in the range of 84.9-95.1% with the relative standard deviations lower than 8.4%. The results showed that the proposed method was a rapid, convenient and feasible method for the determination of formaldehyde in beverage samples. 相似文献
2.
A simple, rapid, and sensitive method using in-tube solid-phase microextraction (in-tube SPME) based on poly(methacrylic acid–ethylene
glycol dimethacrylate) (MAA–EGDMA) monolith coupled to HPLC with fluorescence and UV detection was developed for the determination
of five fluoroquinolones (FQs). Ofloxacin (OFL), norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENRO), and sarafloxacin
(SARA) can be enriched and determined in the spiked eggs and albumins. CIP/ENRO in eggs and albumins of ENRO-treated hens
were also studied using the proposed method. Only homogenization, dilution, and centrifugation were required before the sample
was supplied to the in-tube microextraction, and no organic solvents were consumed in the procedures. Under the optimized
extraction conditions, good extraction efficiency for the five FQs was obtained with no matrix interference in the process
of extraction and the subsequent chromatographic separation. The detection limits (S/N=3) were found to be 0.1–2.6 ng g−1 and 0.2–2.4 ng g−1 in whole egg and egg albumin, respectively. Good linearity could be achieved over the range 2–500 ng mL−1 for the five FQs with regression coefficients above 0.9995 in both whole egg and albumin. The reproducibility of the method
was evaluated at three concentration levels, with the resulting relative standard deviations (RSDs) less than 7%. The method
was successfully applied to the analysis of ENRO and its primary metabolite CIP in the eggs and albumins of ENRO-treated hens. 相似文献
3.
A simple and efficient method, ionic liquid-based dispersive liquid-liquid microextraction combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV), has been applied for the extraction and determination of some antioxidants (Irganox 1010, Irganox 1076 and Irgafos 168) in water samples. The microextraction efficiency factors were investigated and optimized: 1-hexyl-3-methylimidazolium hexafluorophosphate [C(6)MIM][PF(6)] (0.06 g) as extracting solvent, methanol (0.5 mL) as disperser solvent without salt addition. Under the selected conditions, enrichment factors up to 48-fold, limits of detection (LODs) of 5.0-10.0 ng/mL and dynamic linear ranges of 25-1500 ng/mL were obtained. A reasonable repeatability (RSD≤11.8%, n=5) with satisfactory linearity (r(2)≥0.9954) of the results illustrated a good performance of the presented method. The accuracy of the method was tested by the relative recovery experiments on spiked samples, with results ranging from 85 to 118%. Finally, the method was successfully applied for determination of the analytes in several real water samples. 相似文献
4.
Jingkang Li Yanxiao Jiang Ying Sun Xinghua Wang Pinyi Ma Daqian Song Qiang Fei 《Journal of separation science》2022,45(3):697-705
In the present study, we propose a novel method for the extraction of parabens in personal care products. A new, simple adsorptive material was obtained by combining metal-organic frameworks and melamine sponges using the adhesive property of polyvinylidene fluoride. This new material, metal-organic frameworks/melamine sponges, was found to be particularly suitable for solid-phase extraction. The structural characteristics of metal-organic frameworks/melamine sponges were first analyzed by scanning electron microscopy. Subsequently, solid-phase extraction was performed on sample solutions, and the extracted substances were then analyzed by high-performance liquid chromatography. Following optimization of important experimental conditions, excellent recovery rates were obtained. Our novel method was then applied to the extraction of four parabens (methylparahydroxybenzoates, ethylparahydroxybenzoates, propylparahydroxybenzoates, and butylparahydroxybenzoates) from real samples. The results yielded limits of detection of 0.26–0.41 ng/mL. The inter- and intra-day recoveries were 104.0–109.7% and 91.2–98.1%, respectively (relative standard deviation, <13.8%). 相似文献
5.
A dispersive liquid-liquid microextraction (DLLME) method using in situ halide exchange reaction to form ionic liquid (IL) extraction phase was developed to determine four insecticides (i.e. methoxyfenozide, tetrachlorvinphos, thiamethoxam, and diafenthiuron) in water samples. The preconcentration procedure, followed by high-performance liquid chromatography and variable wavelength detectors (VWD), enabled the formation of the immiscible IL extraction phase; the insecticides were transferred into the IL phase simultaneously, which enhanced the efficiency and sufficiency, greatly shortening the operation time. The experimental parameters affecting the extraction efficiency including volume of extraction IL, extraction and centrifugation times, volume of the sample solution and exchanging reagent, and addition of organic solvent and salt were investigated and optimized. Under optimized conditions, the extractions yielded recoveries of the target analytes from 82 to 102%. The calibration curves were linear, and the correlation coefficient ranged from 0.9990 to 0.9999 under the concentration levels of 5-200 μg/L. The relative standard deviation (n=6) was 2.9-4.6%. The limits of detection (LODs) for the four insecticides were between 0.98 and 2.54 μg/L. 相似文献
6.
A novel method, termed ionic liquid cold-induced aggregation dispersive liquid–liquid microextraction (IL-CIA-DLLME), combined with high-performance liquid chromatography (HPLC) was developed for the determination of three phthalate esters in water samples. Several important parameters influencing the IL-CIA-DLLME extraction efficiency, such as the type of extraction and disperser solvent, the volume of extraction and disperser solvent, temperature, extraction time and salt effect, were investigated. Under optimal extraction conditions, the enrichment factors and extraction recoveries ranged from 174 to 212 and 69.9 to 84.8%, respectively. Excellent linearity with coefficients of correlation from 0.9968 to 0.9994 was observed in the concentration range of 2–100 ng mL−1. The repeatability of the proposed method expressed as relative standard deviations ranged from 2.2 to 3.7% (n = 5). Limits of detection were between 0.68 and 1.36 ng mL−1. Good relative recoveries for phthalate esters in tap, bottled mineral and river water samples were obtained in the ranges of 91.5–98.1%, 92.4–99.2% and 90.1–96.8%, respectively. Thus, the proposed method has excellent potential for the determination of phthalate esters in the environmental field. 相似文献
7.
Solid-phase microextraction (SPME) coupled with high-performance liquid chromatography (HPLC) for the determination of triazine is described. Carbowax/templated resin (CW/TPR, 50 μm), polydimethylsiloxane/divinylbenzene (PDMS/DVB, 60 μm), polydimethylsiloxane (PDMS, 100 μm), and polyacrylate (PA, 85 μm) fibers were evaluated for extraction of the triazines. CW/TPR and PDMS/DVB fibers were selected for further study. Several parameters of the extraction and desorption procedure were studied and optimized (such as types of fibers, desorption mode, desorption time, compositions of solvent for desorption, soaking periods and the flow rate during desorption period, extraction time, temperature, pH, and ionic strength of samples). Both CW/TPR and PDMS/DVB fibers are acceptable; a simple calibration-curve method based on simple aqueous standards can be used. The linearity of this method for analyzing standard solution has been investigated over the range 5-1000 ng mL−1 for both PDMS/DVB and CW/TPR fibers. All the correlation coefficients in the range 5-1000 ng mL−1 were better than 0.995 except Simazine and Atratone by CW/TPR fiber. The R.S.D.s range from 4.4% to 8.8 % (PDMS/DVB fiber) and from 2.4% to 7.2% (CW/TPR fiber). Method-detection limits (MDL) are in the range 1.2-2.6 and 2.8-3.4 ng mL−1 for the two fibers. These methods were applied to the determination of trazines in environmental water samples (lake water). 相似文献
8.
A silica nanoparticle (NP)-deposited capillary fabricated by liquid-phase deposition (LPD) and modified with octadecyl groups was introduced for in-tube solid-phase microextraction coupled to high-performance liquid chromatography with UV detection (in-tube SPME–HPLC). The resultant capillary (60 cm × 50 μm I.D.) was demonstrated to be of higher extraction capacity by comparing with an octadecyl-grafted bare capillary and an octadecyl-grafted silica-coated capillary that was prepared by sol–gel chemistry. Two groups of compounds, endocrine disruptors and polycyclic aromatic hydrocarbons, were used as model analytes to further evaluate extraction capacity of the silica NP-deposited capillary, and its reproducibility and stability was also investigated. The extraction time profiles were monitored for all the chemicals, and their limits of detection were calculated to be in the range of 0.42–0.78 and 0.034–0.19 ng/mL with RSD values of peak area less than 4.6%. 相似文献
9.
A simple and reliable method for the determination of polychlorinated biphenyls (PCBs) from mono- to octachlorobiphenyls in fish oil for dietary supplement is described. The method combines Florisil clean up and headspace solid-phase microextraction on 65 microm polydimethylsiloxane-divinylbenzene (PDMS-DVB). Analyte detection was carried out using GC-time-of-flight mass spectrometry (GC-TOF-MS). Fifty three PCB congeners including the seven indicator PCBs (IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180) were analyzed. Under optimal conditions, the method detection limit (MDL) of each congener in the range from 0.8 to 31 ng/g was found. A certified reference material (BCR-349) was analyzed and it showed good agreement with the certified data. 相似文献
10.
In this paper, two methods based on organic solvent dispersive liquid-liquid microextraction (OS-DLLME) and ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) coupled with high-performance liquid chromatography have been critically compared for analyzing emodin and its metabolites (aloe-emodin, anthraquinone-2-carboxylic acid, rhein, danthron, chrysophanol and physcion) in urine samples. Several important parameters influencing the extraction recoveries of DLLME were carefully optimized. Under optimal conditions, the enrichment factors (EFs) for emodin and its metabolites by OS-DLLME and IL-DLLME were within the range of 90-295 and 63-192 respectively; the relative standard deviations (RSDs, n=3) for intra-day and inter-day precision were lower than 7.2 and 8.7% by OS-DLLME, and lower than 5.7 and 6.4% by IL-DLLME; the recoveries of emodin and its metabolites were from 87.1 to 105% for OS-DLLME and from 94.8 to 103% for IL-DLLME, respectively. There were no significant deviations between the two methods for the determination of emodin and its metabolites. From the results of HPLC/UV of urine sample after DLLME, the metabolites aloe-emodin, rhein, chrysophanol and physcion were identified by comparing the retention times with the standards. From the results of HPLC/MS, anthraquinone-2-carboxylic acid and danthron as unreported metabolites of emodin were found. 相似文献
11.
Wentao Han Yang Yang Na Hang Wanning Zhao Pengfei Lu Songqing Li 《Journal of separation science》2022,45(6):1252-1261
In this study, switchable hydrophilic solvent-based dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography was developed for the determination of four sulfonylurea herbicides in soils. For the first time, the sample pretreatment was achieved due to the similar acid-base status of sulfonylurea herbicides and switchable hydrophilic solvent. In the extraction step, sulfonylurea herbicides were extracted as anions and transferred to an alkaline solution with switchable hydrophilic solvent anions. In the concentration step, two types of anions were transformed to their molecular state after the aqueous solution was acidified. In addition, the dispersion and microextraction processes were completed efficiently with the simultaneous formation of analytes and extractants. The factors affecting the extraction performance were optimized. Under the optimized conditions, good linearity was observed for each herbicide with correlation coefficients ranging from 0.9952 to 0.9978. The limits of detection were in the range of 0.1–0.2 μg/g. Moreover, the relative recoveries of the sulfonylurea herbicides at spiking levels of 0.5, 1, and 1.5 μg/g in soil samples were between 75 and 111% (relative standard deviations: 0.4–11.4%). Therefore, the proposed method in this study could be successfully applied to the analysis of four types of sulfonylurea herbicides in soil samples. 相似文献
12.
《Journal of separation science》2017,40(20):4050-4059
A readily applicable method was developed to determine the concentration level of zaltoprofen, a non‐steroidal antiinflammatory drug from the propionic acid family, in human plasma. This method is based on manual‐shaking‐assisted dispersive liquid–liquid microextraction coupled with liquid chromatography with ultraviolet detection. Factors affecting the extraction efficiency were screened and optimized by experimental design using fractional factorial and central composite designs, respectively. Optimal conditions were: 220 μL of C2H4Cl2 (extraction solvent), 5 mL of 3.75% w/v NaCl aqueous solution at pH 2.0, and manual shaking for 13 s (65 times). The resulting extraction method yielded a reasonable enrichment factor of 18.0 (±0.6, n = 3) and extraction recovery of 86.0% (±3.3%, n = 3). The established method was validated for selectivity, linearity, precision, accuracy, matrix effect, recovery, dilution integrity, and stability, and it met the acceptable criteria for all of the tested parameters. Specifically, the method was linear in the range of 0.16–50.0 mg/L, precise (< 8.8% RSD), accurate (–7.5–5.6% deviation), and showed negligible matrix effects (96.1–106.4%) with high absolute recovery (94.5–97.7%). Compared with previous methods involving labor‐intensive liquid–liquid extraction or non‐specific protein precipitation, our method allows the simple, rapid, and efficient determination of zaltoprofen using the most affordable analytical instrument, liquid chromatography with ultraviolet detection. 相似文献
13.
The first dispersive liquid liquid microextraction scheme followed by liquid chromatography‐post column derivatization for the determination of the antiviral drug rimantadine in urine samples is demonstrated. The effect of the type and volume of organic extraction solvent, type and volume of disperser solvent, sample pH, ionic strength, extraction time, and centrifugation speed on the extraction efficiency were studied. Rimantadine and the internal standard (amantadine) were chromatographed using a reversed phase monolithic stationary phase with a mixture of equal volumes of methanol and phosphate buffer (pH = 3) as mobile phase. On‐line post‐column derivatization of the analyte was performed using a “two‐stream” manifold with o‐phthalaldehyde and N‐acetyl‐cysteine at alkaline medium. Under the optimized extraction conditions, the enrichment factor of rimantadine was 58. The linear range was 5–100 µg/L with correlation coefficient r of 0.9984 while the limit of detection achieved was 0.5 µg/L. The within‐day and between‐day precision for the tested concentration levels were less than 14.3% and the mean recoveries obtained from the spiked samples were ranged between 87.5 and 113.9%. The main advantages of the proposed method are the simplicity of operation, rapidity, low cost, and low limit of detection of the analyte. 相似文献
14.
Wen-Hsien Tsai Tzou-Chi Huang Joh-Jong Huang Yi-Huu Hsue Hung-Yi Chuang 《Journal of chromatography. A》2009,1216(12):2263-2269
A dispersive solid-phase microextraction (dispersive-SPME) method for the determination of tetracycline, oxytetracycline, chlortetracycline and doxycycline is proposed. Different silica-based and polymeric sorbents were evaluated for their capacity to simultaneously preconcentrate tetracyclines (TCs) in the dispersive format from aqueous or organic solutions. Silica-based sorbents especially functionalized with primary amine, secondary amine, or carbonyl groups have showed higher capacity than polymeric sorbents under organic environment. In the proposed dispersive solid-phase microextraction method, after extraction with acetonitrile and salt-promoted partitioning, TCs were adsorbed to a small amount of dispersive silica-based primary and secondary amine sorbents, desorbed with a small volume of desorption solution, and determined by high-performance liquid chromatography with diode-array detection. Under the optimal conditions, recoveries were determined for surface water and milk samples spiked at 10 ng/mL and 50–150 ng/g, respectively, and quantification was achieved by matrix-matched calibration. The calibration curves of four TCs in both samples showed linearity with a correlation coefficient value above 0.997. Average recoveries ranged from 97.1 to 104.1% and the precision was from 2.0 to 5.6%. Limits of detection ranged from 0.7 to 3.5 ng/mL and from 7.9 to 35.3 ng/g for four TCs surface in surface water and milk samples, respectively. 相似文献
15.
Amirhassan Amiri Hamid Reza Saadati-Moshtaghin Abbas Abdar Farokhzad Mohammadi Zonoz 《International journal of environmental analytical chemistry》2013,93(11):1017-1029
ABSTRACTIn this work, the magnetic sorbent was developed by covalent binding of a Schiff base ligand, N,N’-bis(3-salicyliden aminopropyl)amine (salpr), on the surface of silica coated magnetic nanoparticles (Salpr@SCMNPs). The core-shell nanoparticle was applied for the magnetic solid-phase extraction (MSPE) combined with dispersive liquid-liquid microextraction (DLLME) of phenolic compounds from water samples prior to gas chromatography-flame ionisation detector (GC?FID). Characterisation of the Salpr@SCMNPs was performed with different physicochemical methods such as Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). Variables affecting the performance of both extraction steps such as pH of the water sample, the sorbent amount, the desorption conditions, the extraction time; and extraction solvent were studied. Under the optimised conditions, the analytical performances were determined with a linear range of 0.01–100 ng mL?1 and a limit of detection at 0.003–0.02 ng mL?1 for all of the analytes studied. The intra-day (n = 5) and inter-day (n = 3) relative standard deviations (RSD%) of three replicates were each demonstrated in the range of 6.9–8.9% and 7.3–10.1%, respectively. The proposed method was executed for the analysis of real water samples, whereby recoveries in the range of 92.9–99.0% and RSD% lower than 6.1% were attained. 相似文献
16.
分散液-液微萃取-气相色谱法快速检测番茄中3种拟除虫菊酯类农药 总被引:3,自引:0,他引:3
建立了快速(quick)、简单(easy)、便宜(cheap)、有效(effective)、可靠(rugged)和安全(safe)(QuEChERS)的分散液-液微萃取(DLLME)-气相色谱快速测定番茄中拟除虫菊酯类农药残留的方法。样品经乙腈提取,N-丙基乙二胺(PSA)净化,采用DLLME富集,用气相色谱法分析。考察了联苯菊酯、甲氰菊酯和氟氰菊酯在番茄中的残留测定,同时考察了萃取剂种类与体积、分散剂体积以及萃取时间等因素对萃取效率的影响,以40 μL氯仿为萃取剂,1000 μL乙腈为分散剂,萃取时间为60 s。结果表明: 3种拟除虫菊酯类农药在番茄中的检出限分别为0.5、0.5、0.3 μg/kg。在1、10和50 μg/kg添加水平下,联苯菊酯、甲氰菊酯和氟氰菊酯在番茄中的平均回收率分别为89%~109%、92.5%~105%和90%~108%,相对标准偏差分别为2.5%~7.6%、2.8%~5.7%、3.8%~9.1%。该方法简便、快速、安全、价格低廉,重现性好,可用于番茄中拟除虫菊酯类农药的快速检测。 相似文献
17.
Chu-Chi Chang 《Analytica chimica acta》2010,662(1):39-65
In this study, the steroid hormone levels in river and tap water samples were determined by using a novel dispersive liquid-liquid microextraction method based on the solidification of a floating organic drop (DLLME-SFO). Several parameters were optimized, including the type and volume of the extraction and dispersive solvents, extraction time, and salt effect. DLLME-SFO is a fast, cheap, and easy-to-use method for detecting trace levels of samples. Most importantly, this method uses less-toxic solvent. The correlation coefficient of the calibration curve was higher than 0.9991. The linear range was from 5 to 1000 μg L−1. The spiked environmental water samples were analyzed using DLLME-SFO. The relative recoveries ranged from 87% to 116% for river water (which was spiked with 4 μg L−1 for E1, 3 μg L−1 for E2, 4 μg L−1 for EE2 and 9 μg L−1 for E3) and 89% to 102% for tap water (which was spiked with 6 μg L−1 for E1, 5 μg L−1 for E2, 6 μg L−1 for EE2 and 10 μg L−1 for E3). The detection limits of the method ranged from 0.8 to 2.7 μg L−1 for spiked river water and 1.4 to 3.1 μg L−1 for spiked tap water. The methods precision ranged from 8% to 14% for spiked river water and 7% to 14% for spiked tap water. 相似文献
18.
Dispersive liquid-liquid microextraction (DLLME) coupled with high-performance liquid chromatography (HPLC)-UV detection was applied in rat urine for the extraction and determination of tetrahydropalmatine (THP) and tetrahydroberberine (THB), both active components in Rhizoma corydalis. Various parameters affecting the extraction efficiency, such as the type and volume of extraction and dispersive solvent, pH, etc. were evaluated. Under the optimal conditions (extraction solvent: 37 μL of chloroform, dispersive solvent: 100 μL of methanol, alkaline with 100 μL of 1 mol/L NaOH, and without salt addition), the enrichment factors of THP and THB were more than 30. The extraction recoveries were 69.8-75.8% and 72.7-77.6% for THP and THB in rat urine, respectively. Both THP and THB showed good linearity in the range of 0.025-2.5 μg/mL, and the limit of quantification was 0.025 μg/mL (S/N=10, n=6). The intra-day and inter-day precision of THP and THB were <12.6%. The relative recoveries ranged from 95.5 to 107.4% and 96.8 to 100.9% for THP and THB in rat urine, respectively. The method has been successfully applied to rat urine samples. The results demonstrated that DLLME is a very simple, rapid and efficient method for the extraction and preconcentration of THP and THB from urine samples. 相似文献
19.
A novel one-step sample preparation technique called ultrasound-assisted matrix solid-phase dispersive liquid extraction was developed. After sample matrices being dispersed, target analytes were extracted into acid solutions and fat and lipin were dissolved in n-hexane while the interfering components were retained by dispersing sorbent. The extraction process could be rapidly accomplished within 9 min with high sample throughput under the synergistic effects of vibration, ultrasound action and heating. The extraction efficiency of approach was demonstrated for the determination of intermediates in commercial hair dyes with ion chromatography. Linearity ranges of 0.2–100 mg L−1 and detection limits varying from 0.019 to 0.048 mg L−1 were achieved. The recoveries ranged from 85.7 to 107.0% with the relative standard deviations (RSDs) of 0.31–3.7%. These results showed that the method was simple, time-saving, reliable and suitable for the routine analysis of intermediates in large numbers of hair dyes. 相似文献
20.
悬浮固化分散液液微萃取-高效液相色谱法测定水体中邻苯二甲酸酯 总被引:1,自引:0,他引:1
建立了悬浮固化分散液液微萃取(SFO-DLLME)结合高效液相色谱(HPLC)快速测定水样中6种邻苯二甲酸酯(PAEs)的分析方法。通过对影响萃取效率因素的优化,确定了最佳萃取条件:十二烷醇萃取剂20 μL、萃取温度60℃、离子强度20 g/L、萃取时间1 min。6种PAEs在2~2000 μg/L范围内呈良好的线性关系,相关系数(r)为0.9995~0.9999,检出限(S/N=3)为0.3~0.6 μg/L。对自来水、湖水、江水、污水、海水、市售塑料瓶装纯净水和矿泉水进行测定,能检测到部分PAEs。对加标水样进行回收率试验(10、100和1000 μg/L),6种PAEs的回收率为84.9%~94.5%,相对标准偏差为4.1%~6.8%(n=5)。该法环保、简单,可用于实际水样中6种PAEs的检测分析。 相似文献