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1.
This paper describes the development of a method for the simultaneous determination of ten anticoagulant rodenticides (coumafuryl, warfarin, pindone, coumatetralyl, coumachlor, difenacoum, bromadiolone, brodifacoum, chlorophacinone and flocoumafen) in the liver and kidney based on column-switching liquid chromatography coupled with heated electrospray ionization tandem mass spectrometry. The simple sample preparation includes extraction with methanol. A C18 trapping column was used for online solid-phase extraction before analytical separation with the mobile phase comprising a mixture of 0.1 % formic acid in water, methanol and acetonitrile. Chromatographic separation was achieved using a Thermo Hypersil ultra high-performance liquid chromatography (UHPLC) C18 column with the mobile phase consisting of 5 mM ammonium formate buffer (pH?=?9) and methanol. The column-switching procedure ensured no matrix effects during electrospray ionization (ESI). Extraction recoveries ranged between 91 and 100 % for liver and between 89 and 97 % for kidney. The method showed good linearity up to 750 ng g?1. The limit of detection ranged between 0.001 and 0.022 ng g?1 for liver and between 0.001 and 0.028 ng g?1 for kidney. The developed method was successfully used in several animal poisoning cases.  相似文献   

2.
Nonylphenol (NP), octylphenol (OP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) are products of the biodegradation of alkylphenol polyethoxylates (AP n EO) which are used worldwide as detergents and surfactants. NP and OP are categorized as definitely endocrine disruptors. 2,4-Tert-butylphenol (BP) is extensively used for anti-oxidant of rubber and plastics. This work proposed a simple and stable method for simultaneously determining the concentration of NP, OP, BP, n-NP1EO and n-NP2EO in meat and fish, without requiring the complex pretreatments of current methods. This study used liquid extraction with acetonitrile and hexane and solid extraction using Florisil, in that order to pretreat samples. The sample solutions were analyzed to identify NP, OP, BP, n-NP1EO and n-NP2EO by HPLC with fluorescence detection. The mean recoveries were 85.3?±?3.32% for OP, 87.5?±?6.01% for BP, 90.9?±?4.72% for NP, 86.4?±?4.81% for n-NP2EO and 90.9?±?4.84% for n-NP1EO. The average coefficients of variation were about 6%. The method's detection limits were 5.4?ng?g?1 for OP, 5.2?ng?g?1 for BP, 8.9?ng?g?1 for NP, 8.7?ng?g?1 for n-NP2EO and 8.1?ng?g?1 for n-NP1EO. This work analyzed 5 kinds of usual foodstuffs of meat and fish that are frequently consumed by residents of Taiwan. All of these samples contained NP, but not detectable levels n-NP1EO. Only salmon was contaminated with n-NP2EO. The NP level was highest in cod (198.41?±?129.34?ng?g?1, wet weight). The fried chicken had the highest BP level (48.0?±?41.3?ng?g?1, wet weight), and the uncooked chicken had the highest OP level (66.6?±?53.0?ng?g?1, wet weight).  相似文献   

3.
An efficient and fast microwave-assisted extraction (MAE) method followed by gas chromatographic separation with mass spectrometric detection (GC–MS) was developed for the extraction of 18 organochlorine pesticides (OCPs) from sediment. Parameters affecting the MAE procedure such as the type and volume of the extraction solvent, irradiation power, temperature and irradiation time were successfully optimised. Under the optimal conditions, extraction efficiencies in the range of 73.4–119% were obtained with THF–HEX (9:1, v/v) for all OCPs studied. The method was linear over the range of 2.9–5000 ng g?1 with determination coefficients (r2) higher than 0.992 for all analytes. The limits of detection, LODs (S/N = 3), obtained varied from 1.0 to 2.2 ng g?1 and limits of quantification, LOQs (S/N = 10) were between 2.9 and 6.8 ng g?1. The proposed method was successfully applied to the analysis of real sediment samples and acceptable recoveries from 70.1 to 124% with RSDs ≤14.8% were obtained. 10 OCPs were determined below their LOQ and 8 OCPs in the range of 124–2830 ng g?1. The MAE method was compared with Soxhlet, shake flask and ultrasonic solvent extraction techniques. Thus, the MAE–GC–MS method could efficiently be used for selective extraction and quantification of the target analytes from the complex sediment matrices.  相似文献   

4.
The validation of a multiresidue method for the determination of organochlorine, organophosphorus, pyrethroid and dicarboximide pesticides in honeybees is described. The method involves the extraction of 25 pesticides using acetonitrile, liquid partitioning with n-hexane and a clean-up performed on a silica gel cartridge (1 g, 12 mL). Capillary gas chromatography with electron-capture and nitrogen–phosphorus detectors was used for analytes determination. Limit of quantification (LOQ), recovery and relative standard deviation (RSD) for each analyte were determined. The recovery data were obtained by spiking honeybee samples free of pesticides at three levels (LOQ, 4LOQ and 8LOQ) with organochlorine, organophosphorus, pyrethroid and dicarboximide pesticides. The recoveries were in the range between 90.0% and 101.5% for LOQ, between 90.3% and 104.8% for 4LOQ and between 88.1% and 101.6% for 8LOQ with RSD less than 20% for the three levels tested. The lowest LOQ value was 1 ng bee?1 (corresponding to 10 ng g?1) and the highest LOQ value was 10 ng bee?1 (corresponding to 100 ng g?1). These LOQ values are lower than the lethal doses LD50 (acute contact toxicity and acute oral toxicity) of each pesticide for bees.  相似文献   

5.
An analytical chemical method has been developed for the simultaneous determination of 32 different pharmaceuticals in soils and sediments. The pharmaceuticals cover a varity of different compound groups. Soil samples were extracted with different solvents with the help of pressurized-liquid extraction (PLE) followed by clean-up using a solid-phase extraction (SPE) procedure. The purified extracts were analyzed by LC-MS/MS. The extraction method was evaluated by testing the following variables: extraction solvents, solvent pH, and temperature. Applying 20 g of soil/sediment and extracting with a mixture of methanol with aqueous ammonia solution (0.1 mol L?1) at 80?°C for 5 min in five cycles provided satisfactory recoveries between 66 and 114% with SD of between 1 and 14%. For preconcentration and purification tandem MAX-HLB cartridges were used. The volume and composition was optimized and the highest recoveries were obtained with a combination of methanol—aqueous ammonia solution. The limits of quantification (LOQs) were between 0.2 and 2 ng g?1 and linearity higher than 0.98 for the majority of the selected pharmaceuticals. The method was successfully applied to soil samples collected from the Jerez de la Frontera agricultural region, irrigated with treated wastewater, and to sediment samples from the River Guadalete. The detection of nine pharmaceuticals including stimulants, antirheumatics, analgesics, anti-inflammatories, tranquilizers, and veterinary medicines at ng g?1 concentration levels was achieved.  相似文献   

6.
The objective of this study was to develop a simple, efficient and reliable method for routine quantitative analysis for Psoralea corylifolia L. An ultra performance liquid chromatography with DAD detector system was employed for simultaneous quantification of ten compounds. The chromatographic analysis was performed by UPLC with C18 column and gradient elution of 0.05% formic acid aqueous solution and acetonitrile in 16 min. All calibration curves were linear (R 2 ≥ 0.9990) over the tested ranges. The LOD and LOQ were lower to 13.07 and 39.22 ng mL?1 with 2 μL of injection volume, respectively. The intra- and inter-day precisions as determined from sample solutions were below 4.1 and 4.2%. The average recoveries were ranged from 94.2 to 108.8% with RSDs ≤ 4.6%. This validated method was applied for the analysis of ten analytes in P. corylifolia L. from different origins. The variation of the content of ten compounds was remarkable among the tested samples: psoralenoside increased from 7.42 to 17.04 mg g?1, isopsoralenoside from 6.05 to 14.34 mg g?1, psoralen from 2.37 to 3.90 mg g?1, isopsoralen from 2.53 to 3.65 mg g?1, neobavaisoflavone from 1.59 to 2.96 mg g?1, bavachin from 1.02 to 2.35 mg g?1, psoralidin from 0.45 to 1.91 mg g?1, isobavachalcone from 1.33 to 4.71 mg g?1, corylifol A from 1.02 to 2.40 mg g?1 and bakuchiol from 28.10 to 63.89 mg g?1.  相似文献   

7.
《Analytical letters》2012,45(6):966-981
Triorganotins in seafood are a risks to human health, but due to their low concentrations, their determination is challenging. In this study, a simple and rapid method was developed to isolate triorganotins from seafood by microwave-assisted extraction coupled with magnetic nanoparticle-based purification. The magnetic nanoparticles were coated with octanoic acid. Triethyltin chloride, tributyltin chloride, triphenyltin chloride, and azocyclotin were determined by high performance liquid chromatography– inductively coupled plasma mass spectrometry (HPLC–ICP-MS). Various parameters including the temperature, time, and volume of solvent were optimized to improve the extraction efficiency. Under the optimized conditions, the average recoveries (n = 6) of the triorganotins (fortified at 0.01, 0.02, and 0.05 µg g?1) were between 73.8% and 105.4% and the relative standard deviations were less than 10.4%. The procedure was successfully applied to seafood, and the analytes were measured at concentration levels between 2.93 and 11.26 ng g?1.  相似文献   

8.
A flow-injection method coupled with the luminol chemiluminescence (CL) detection was developed for the simultaneous determination of carbaryl and 1-naphthol in soils. The method is based on the inhibition of luminol oxidation by the presence of 1-naphthol with the consequent reduction in the CL intensity. The conversion of carbaryl into 1-naphthol was made by the alkaline hydrolysis with NaOH. Under the optimised conditions, the method permits the determination of carbaryl and 1-naphthol over the range 25–400 ng mL?1 with high determination coefficient using both peak area and height, and high sample throughput (40 h?1). The detection limits applying the International Unión of Pure and Applied Chemistry (IUPAC) criteria were 65 ng g?1 and 123.5 ng g?1 for peak height and area, respectively. A simple extraction procedure employing chloroform as the solvent and sonication was effective for the complete extraction of the analytes present in soils. The method was validated by the analysis of spiked samples, with recoveries between 88.7 and 103.1%. The Flow Injection-Chemiluminescence (FI-CL) method has proven to be simple, fast and accurate for the quantification of carbaryl and its main degradation product in soils.  相似文献   

9.
We have prepared core-shell magnetic molecularly imprinted polymer nanoparticles for recognition and extraction of tributyl tin (TBT). The use of particles strongly improves the imprinting effect and leads to fast adsorption kinetics and high adsorption capacities. The functional monomer acrylamide was grafted to the surface of Fe3O4 nanospheres in two steps, and MIP layers were then formed on the surface by creating a MIP layer on the surface consisting of poly(ethyleneglycol dimethacrylate) with a TBT template. The particles were characterized in terms of morphological, magnetic, adsorption, and recognition properties. We then have developed a method for the extraction of TBT from spiked mussel (Mytilidae), and its determination by liquid chromatography-tandem mass spectrometry. The method has a limit of detection of 1.0 ng?g?1 (n?=?5) of TBT, with a linear response between 5.0 and 1,000 ng?g?1. The proposed method was successfully applied to the determination of trace TBT in marine food samples with recoveries in the range of 78.3–95.6 %.
Figure
The preparation procedures of core-shell magnetic molecularly imprinted polymer nanoparticles for recognition and extraction of tributyl tin (TBT) in seafood  相似文献   

10.
A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of Meserine ((?)-meptazinol phenylcarbamate), a novel potent inhibitor of acetylcholinesterase (AChE), was developed, validated, and applied to a pharmacokinetic study in mice brain. The lower limit of quantification (LLOQ) was 1 ng mL?1 and the linear range was 1–1,000 ng mL?1. The analyte was eluted on a Zorbax SB-Aq column (2.1?×?100 mm, 3.5 μm) with the mobile phase composed of methanol and water (70:30, v/v, aqueous phase contained 10 mM ammonium formate and 0.3 % formic acid) using isocratic elution, and monitored by positive electrospray ionization in multiple reaction monitoring (MRM) mode. The flow rate was 0.25 mL min?1. The injection volume was 5 μL and total run time was 4 min. The relative standard deviation (RSD) of intraday and interday variation was 2.49–7.81 and 3.01–7.67 %, respectively. All analytes were stable after 4 h at room temperature and 6 h in autosampler. The extraction recoveries of Meserine in brain homogenate were over 90 %. The main brain pharmacokinetic parameters obtained after intranasal administration were T max?=?0.05 h, C max?=?462.0?±?39.7 ng g?1, T 1/2?=?0.4 h, and AUC(0-∞)?=?283.1?±?9.1 ng h g?1. Moreover, Meserine was distributed rapidly and widely into brain, heart, liver, spleen, lung, and kidney tissue. The method is validated and could be applied to the pharmacokinetic and tissue distribution study of Meserine in mice.  相似文献   

11.
Well-dispersed resorcinol-formaldehyde-based carbon spheres (RFCs) have been prepared by the polycondensation of resorcinol and formaldehyde with ammonia as catalyst and subsequent carbonization of the obtained polymer. In situ polymerization of the aniline occurred in the suspension of the RFC, and RFC was surrounded by the polyaniline (PANI) wires. The PANI and RFC hybrid network (PRFC) formed gradually. In a three-electrode mode, the specific capacitance (C sp) of PRFC reaches 315 F g?1 at a current density of 1 A g?1 in 2 M H2SO4, much higher than that of pure PANI (225 F g?1) and RFC (121.7 F g?1). Furthermore, the C sp of PRFC retains 80.0 % after 1000 charge-discharge processes at a current density of 5 Ag?1. The enhanced electrochemical performance of the PRFC came from its homogeneous three-dimensional hierarchical network structure, good electric conductivity of the PANI around the RFC, and the synergistic effect between the RFC and PANI.  相似文献   

12.
A sensitive and selective liquid chromatography–mass spectrometric method was developed and validated for the determination of p-(1-dimethylamino ethylimino)aniline (dADT), a metabolite of tribendimidine, in human plasma. The analyte was separated on a Hypersil C18 column (250 × 4.6 mm ID, 5 μm) by isocratic elution with 10 mM ammonium acetate (containing 0.1% triethylamine)-acetonitrile (20:80, v/v) at a flow rate of 1.0 mL min?1 and measured by electrospray ionization source in positive selective ion monitoring mode at m/z 178. The weighted (1/x 2) calibration curve was linear within a concentration range of 0.5–1,000 ng mL?1 and displayed a correlation coefficient (r) of 0.9996. The lower limit of quantification was determined to be at 0.5 ng mL?1. The inter and intra-day precisions (%RSD) were less than 8% and the extraction recoveries ranged from 84.21 to 85.20%. The developed method was successfully applied to the determination of dADT in human plasma as part of a clinical pharmacokinetic study.  相似文献   

13.
《Analytical letters》2012,45(10):1352-1367
Abstract

A simple, expeditious, and sensitive method has been developed for the determination of low-molecular-mass aldehydes in water samples by liquid chromatography and peroxyoxalate–chemiluminescence detection. The method is based on continuous solid-phase extraction with in situ derivatization/preconcentration of the aldehydes using dansylhydrazine, which was first adsorbed on an RP–C18 mini-column. For 10 mL of aqueous sample, the limits of detection (LOD) for C1 to C4 aldehydes were 20–30 ng L?1, except for formaldehyde, which had an LOD of 400 ng L?1. Application was illustrated by the determination of these aldehydes in water samples; the interday precision was always less than ca. 7%, and relative recoveries were more than 96%.  相似文献   

14.
《Analytical letters》2012,45(10):1842-1852
A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Fluorescence spectrometers as detectors was developed to analyze mercury, arsenic, and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimized by a multivariate approach. The optimal conditions were found to be 1% HNO3 extractant solution used at a flow rate of 1 mL min?1. The duty cycle and amplitude of the ultrasonic probe was found to be 50% in both cases with an ultrasound power of 400 W. The optimal distance between the probe and the top face of the extraction chamber was found to be 0 cm. Under these conditions the time required for complete extraction of the three analytes was 25 min. Cold vapor and hydride generation coupled to atomic fluorescence spectrometry was utilized to determine mercury and arsenic, respectively. The chemical and instrumental conditions were optimized to provide detection limits of 0.01 ng g?1 and 1.25 ng g?1 for mercury and arsenic, respectively. Barium was determined by graphite-furnace atomic absorption spectrometry, with a detection limit of 25 ng g?1. By using 0.5 g of sample, the concentrations of the target analytes varied for the different types of paper and ranged between 0.4–2.55 µg g?1 for Ba, 0.035–10.47 µg g?1 for As, and 0.0046–2.37 µg g?1 for Hg.  相似文献   

15.
In this study, energetic interactions between activated carbon monoliths and various liquids were evaluated by determining immersion enthalpies in C6H6, H2O and aqueous solutions of NaOH and HCl. Immersion enthalpies depend on both the surface chemistry and the interactions between specific groups, and were compared with results from volumetric titrations. Immersion enthalpies of activated carbon monoliths were between ?95.85 and ?176.5 J g?1 for C6H6 and between ?11.19 and ?68.31 J g?1 for H2O; whereas immersion enthalpies in NaOH and HCl solutions were between ?20.36 and ?82.25 J g?1 and ?18.81 and ?96.16 J g?1, respectively. In support of these results, a high level of acidic groups was found on the surface of the activated carbon monoliths by Boehm volumetric titrations, with values between 719 and 1,290 g mol?1, in agreement with the higher immersion enthalpies observed in NaOH. Correlations were established between immersion enthalpies in the liquids and the surface chemistry properties of the activated carbon monoliths determined by volumetric titrations, demonstrating that immersion enthalpy is a useful parameter for characterisation of these materials in specific liquids.  相似文献   

16.
《Analytical letters》2012,45(5):787-799
A C18 stationary phase was synthesized for a custom-made HPLC column. When compared to a commercial C18 column, better chromatographic performances were obtained. This column was successfully applied for simultaneous determination of p,p′-DDT, o,p′-DDT, benzo(a)anthracene, benzo(b)fluoranthene, and benzo(a)pyrene in waters by high performance liquid chromatography coupled with dual detectors (diode array and fluorescence detectors) combined with solid phase extraction. Low method detection limits were obtained, i.e., p,p′-DDT: 0.5 µg L?1, o,p′-DDT: 1 µg L?1, benzo(a)anthracene: 2.5 ng L?1, benzo(b)fluoranthene: 5 ng L?1, and benzo(a)pyrene: 2.5 ng L?1. High recoveries that ranged from 82 to 94% were obtained for all compounds.  相似文献   

17.
Ultrasound-assisted emulsification microextraction was applied to extract the herbicides simazine, atrazine, prometon, ametryn and prometryn from soil samples. They then were determined by HPLC with diode-array detection. Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, emulsification time and addition of salt, were optimized. Under the optimum conditions, the following analytical figures of merits are found: enrichment factors between 145 and 222, limits of detection between 0.1 to 0.5 ng g?1, analytical linearity in the range from 1.0 to 200 ng g?1, correlation coefficients (r) between 0.9989 and 0.9998, relative standard deviations from 2.8% to 3.6% (at n?=?5, intraday) and 3.7% to 4.3% (interday), and recoveries (at spiking levels of 5.0 and 50.0 ng g?1) from 82.6% to 92.0%. The technique is simple, practical, rapid, and environmentally friendly.  相似文献   

18.
Fragment-imprinted microspheres (FIMs) were synthesized by suspension polymerization of 4-sulfa-6-chloropyrimidine (the template), methacrylic acid and styrene (the mixed functional monomers), divinylbenzene (the crosslinker), and azobisisobutyronitrile (the initiator). The optimum conditions were obtained by an orthogonal experiment. After removal of the templates, the microspheres serve as a material to fairly specifically bind sulfonamides, the absorption capacity being 6.32 mg g–1, whereas the absorption by non-imprinted microspheres is 1.68 mg g?1. A method was worked out for the simultaneous determination of five sulfonamides by solid phase extraction (using the FIMs) coupled to HPLC, and applied to analyze milk samples. The recoveries are within 87.6 and 96.5 %, with relative standard deviations between 1.25 and 2.89 %.
Figure
Graphical abstract showed that fragment imprinted-solid phase extraction had the best selective adsorption performance of the five sulfonamide antibiotics compare with C18, Silica and Florisil column. It was satisfactory by using fragment imprinted microspheres as sorbents of solid phase extraction for enriching and separating target compounds from complex matrices.  相似文献   

19.
A new sample-treatment procedure has been developed for determination of total linear alkylbenzene sulfonate (LAS), i.e. homologues and isomers, in agricultural soil. The procedure involves two steps, ultrasound-assisted extraction of LAS from the samples with methanol then clean-up of the methanolic extracts and preconcentration of the LAS by solid-phase extraction on two adsorbent cartridges (SAX and C18). The ultrasound-assisted procedure reduces extraction time (10 min in contrast with 6–12 h for conventional Soxhlet extraction) and requires only small volumes of organic solvent. The effect of different variables interacting in the ultrasound-assisted extraction process was studied. Finally, separation and quantification of the homologues and isomers of LAS was performed by liquid chromatography with fluorescence detection (LC?FD). 2-Octylbenzenesulfonic acid sodium salt (Na-2ØC8-LAS) was used as internal standard. The proposed method was satisfactorily used for determination of LAS in agricultural soil samples from the fertile plain of Granada (Spain).
Figure LAS treatment, a field experience
  相似文献   

20.
《Analytical letters》2012,45(14):1995-2005
Using 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) ionic liquid as extraction solvent, five estrogens including estrone (E1), 17β-estradiol (E2), estriol (E3), 17α -ethynylestradiol (EE2), and diethylstilbestrol (DES) in water samples were determined by dispersive liquid-liquid microextraction (DLLME) followed by high performance liquid chromatography with a photodiode array detector and a fluorescence detector (HPLC-DAD-FLD). The extraction procedure was induced by the formation of cloudy solution, which was composed of fine drops of [C6MIM][PF6] dispersed entirely into the sample solution with the help of a disperser solvent (acetone). Parameters including both extraction and disperser solvents and their volumes, extraction and centrifugal time, sample pH, and salt effect were investigated and optimized. Under the optimized conditions, 110–349 fold enrichment factors of analytes were obtained. The calibration curves were linear in the concentration range of 0.2–100 µg L?1 for E2, E3, and EE2 detected with FLD, and 1–100 µg L?1 for E1 and DES detected with DAD. The correlation coefficient of the calibration curve was between 0.9990 and 0.9997. The limits of detection (LOD, S/N = 3) for the five estrogens were in the range of 0.08–0.5 µg L?1. The relative standard deviations (RSD) for six replication experiments at the concentration of 5.0 µg L?1 were ≤5.7%. The proposed method was applied to the analysis of three water samples from different sources (river water, waste water, and sea water). The relative recoveries of spiked water samples are satisfied with 89.3–102.4% and 88.7–105.2% at two different concentration levels of 5.0 and 50.0 µg L?1, respectively.  相似文献   

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