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1.
    
In this paper, we describe the development of an oil-absorbing matrix solid-phase dispersion extraction with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry suitable for screening of 68 pesticide residues (PRs) in peanut, soybean, rape seed, sesame, and sunflower seed. The 68 PRs include 27 kinds of organophosphorus, 23 organic chlorines, 11 synthetic pyrethroids, and 7 carbamates. Heptachlor epoxide was used as the internal standard. Aminopropyl silica was chosen as the dispersion sorbent of the oil-absorbing matrix solid-phase dispersion extraction and was applied to capture hydrophobic components from high oil samples. A 35-min orthogonal separation was performed by using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry with a nonpolar-polar column set. Identification of 68 PRs in the extract was finished by using the time-of-flight mass spectrometry in the assistance of an automated peak-find and spectral deconvolution software. A screening based on control design was introduced and explained. This screening method considerably reduced the cost for the quantitative and confirmatory analyses. The quality of present screening method was evaluated by the Document No. SANCO/10684/2009. The false positive rate and false negative rate provide a useful tool for the evaluation of screening performance.  相似文献   

2.
  总被引：1，自引：0，他引：1  
In this study, in‐line solid‐phase extraction (SPE) was used as an enrichment technique in combination with CE for the preconcentration and separation of 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine (EDDP), cocaine (COC), codeine (COD) and 6‐acetylmorphine (6AM). The separation buffer (BGE) used was 80 mM disodium phosphate anhydrous and 6 mM of HCl (final BGE pH of 3). The SPE extractor consists of a small segment of capillary filled with Oasis HLB sorbent and inserted into the inlet section of the electrophoretic capillary. Different parameters affecting preconcentration were evaluated, such as sample pH, the volume of the elution plug and sample injection time. The detection limits (LODs) reached for standard samples by in‐line SPE‐CE‐UV ranged between 50 and 200 ng/L, with sensitivity enhancement factors ranging from 2300 to 5300. Reproducibility values (expressed in terms of relative standard deviation) were below 7.6% for standard samples. This is a simple and an effective method for the determination of the studied drugs of abuse and their metabolites. The applicability of the developed method was demonstrated in tap and river water samples which were directly analyzed without any off‐line pretreatment. Analytical parameters were evaluated and LODs were between 70 and 270 ng/L with relative recoveries between 85 and 97%.  相似文献   

3.
    
The simultaneous determination of amphetamine and methadone was carried out by magnetic graphene oxide nanoparticles, a magnetic solid‐phase extraction adsorbent, as a new sample treatment technique. The main factors (the amounts of sample volume, amount of adsorbent, type and amount of extraction organic solvent, time of extraction and desorption, pH, the ionic strength of extraction medium, and agitation rate) influencing the extraction efficiency were investigated and optimized. Under the optimized conditions, good linearity was observed in the range of 100–1500 ng/mL for amphetamine and 100–1000 ng/mL for methadone. The method was evaluated for determination of AM and methadone in positive urine samples, satisfactory results were obtained, therefore magnetic solid‐phase extraction can be applied as a novel method for the determination of drugs of abuse in forensic laboratories.  相似文献   

4.
A novel method is described for the extraction of methamphetamine, amphetamine, and methylenedioxyphenylalkylamine designer drugs, such as 3,4-methylenedioxy-methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxyethylamphetamine, N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine, and 3,4-(methylenedioxyphenyl)-2-butanamine, from human whole blood using molecularly imprinted solid-phase extraction as highly selective sample clean-up technique. Whole blood samples were diluted with 10 mmol/L ammonium acetate (pH 8.6) and applied to a SupelMIP-Amphetamine molecularly imprinted solid-phase extraction cartridge. The cartridge was then washed to eliminate interferences, and the amphetamines of interest were eluted with formic acid/methanol (1:100, v/v). After derivatization with trifluoroacetic anhydride, the analytes were quantified using gas chromatography-mass spectrometry. Recoveries of the seven amphetamines spiked into whole blood were 89.1-102%. The limits of quantification for each compound in 200 μL of whole blood were between 0.25 and 1.0 ng. The maximum intra- and inter-day coefficients of variation were 9.96 and 13.8%, respectively. The results show that methamphetamine, amphetamine, and methylenedioxyphenylalkyl-amine designer drugs can be efficiently extracted from crude biological samples such as whole blood by molecularly imprinted solid-phase extraction with good reproducibility. This extraction method will be useful for the pretreatment of human samples before gas chromatography-mass spectrometry.  相似文献   

5.
    
Drying is a critical step to prolong the storage time in natural medicine processing but it changes the chemical characteristics of the product. In this study, research was performed to characterize the metabolomic changes in toad venom induced by vacuum‐drying at 60°C and air‐drying at room temperature by ultra high performance liquid chromatography coupled with pattern recognition approaches. In total 52 metabolites, down‐regulated or up‐regulated, were identified as potential chemical markers. Compared with fresh toad venom, vacuum‐drying at 60°C succeeded in raising the conjugated‐type bufadienolide content significantly, while the content of free‐type bufadienolides were slightly reduced. On the other hand, toad venom air‐dried at room temperature presented a relatively low amount of bufadienolides compared with fresh venom. For example, the content of several known anti‐tumor components (gamabufotalin, bufotalin, cinobufagin, etc.) were significantly reduced. The 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide bioassay further showed that venom air‐dried at room temperature had weaker anti‐tumor activity on human hepatocellular carcinoma SMMC‐7721 proliferation in vitro than samples vacuum‐dried at 60°C. These results showed that the great metabolomic changes of toad venom occurred during the drying process, suggesting that a proper drying procedure is important for sustaining the chemical quality of natural medicines.  相似文献   

6.
    
A method based on liquid chromatography with electrospray ionization high‐resolution mass spectrometry (Exactive Orbitrap) combined with solid‐phase extraction using a strong cationic exchange mixed‐mode sorbent has been developed for the determination of seven drugs of abuse, including two synthetic cathinones, as well as some of their metabolites in environmental water samples. The method provides low detection limits and a high confirmation power thanks to the diagnostic and two fragment ions monitored for each compound in high‐resolution mass spectrometry, providing six identification points for each analyte. The clean‐up step based on methanol in the extraction step adequately decreased the matrix effect, mainly for river and effluent water, and provided suitable process efficiency. Method detection and quantitation limits for environmental waters were at low nanogram per liter. The method was applied to analyze the samples of influent and effluent wastewater, as well as surface water. Codeine, methadone, and its metabolite were determined in all samples of wastewater and the metabolite of cocaine, benzoylecgonine, was found at the highest concentration.  相似文献   

7.
    
A rapid and high-throughput isotope dilution LC-MS/MS method with online sample pre-concentration and clean-up using anionic mixed-mode SPE was described for the determination of closantel and rafoxanide in edible bovine and ovine tissues. Tissue samples were extracted with acetonitrile and acetone mixture (60:40, v/v). Sample pre-concentration, clean-up and analysis were completed simultaneously with the online MAX SPE LC-MS/MS system. Closantel-(13) C(6) and rafoxanide-(13) C(6) were used as the internal standards to improve the precision of the method. The method was validated with edible ovine and bovine tissues (muscle, kidney and liver) fortified at three different levels. The accuracy and RSD were 86-106% and ≤14%, respectively. This high-throughput method was suitable for routine quantitative analysis of closantel and rafoxanide in food safety surveillance samples.  相似文献   

8.
    
Determination of pregabalin in urine samples was carried out by nonaqueous CE with TOF‐MS via ESI, with a mixture of 10 mM ammonium formate and 0.05% acetic acid in methanol. By using TOF‐MS, accurate mass information was obtained, thus causing a great improvement in qualitative ability. In order to avoid ionic suppression, urine samples dilution 1:10 was used. This was the only treatment to urine samples before the injection. Despite this dilution, the detection limit was as low as 0.03 μg/mL for pregabalin. The method was validated with respect to accuracy, precision, and linearity, LOD, and LOQ. This method was applied to the analysis of urine samples from seven different cancer patients undergoing treatment with pregabalin. The developed method may find wide application for the routine determination of pregabalin in biological samples in order to establish a more efficient and safe dosage.  相似文献   

9.
    
Automated online SPE‐HPLC‐MS was established for the determination of deca‐bromodiphenyl ether in human serum. The online SPE with large volume injection was utilized to enhance the sensitivity. Online SPE with dilution line greatly decreased matrices effect, which enabled serum samples to be injected directly into pre‐column. Washing line was designed for the system to solve the serious residual phenomenon and reduce the risk of sample wastage and contamination. Under the optimized conditions, the linear of the method was in the range 0.1–10 ng/mL with the LOD of 0.026 ng/mL. The recoveries of serum samples spiked with deca‐bromodiphenyl ether at 0.5 ng/mL was in the range from 83.30 to 102.7% with RSD in interday less than 8.67%. The satisfactory results demonstrated that the method of online sample pretreatment and cleanup recycle were reliable for human serum analysis.  相似文献   

10.
    
In this work, a novel, rapid, and simple analytical method was proposed for the detection of parabens in milk sample by gas chromatography coupled with mass spectrometry. At the same time, milk sample was pretreated by magnetic solid phase extraction, which detected up to five parabens. A series of important parameters of magnetic solid phase extraction were investigated and optimized, such as pH value of loading buffer, amount of material, adsorption time, ionic strength, eluting solvents, and eluting time. Under the optimized conditions, the corresponding values were more than 0.9991, limits of detection and the limit of quantification were 0.1 and 0.5 ng/mL, respectively. In addition, the recoveries were achieved in range of 95–105%, the liner range were within 0.1–600 ng/mL, and the relative standard deviations were even lower than 5%.  相似文献   

11.
    
A novel and simple online solid‐phase extraction liquid chromatography‐tandem mass spectrometry method was developed and validated for the simultaneous determination of diazepam and its five metabolites including nordazepam, oxazepam, temazepam, oxazepam glucuronide, and temazepam glucuronide in human oral fluid. Human oral fluid was obtained using the Salivette® collection device, and 100 μL of oral fluid samples were loaded onto HySphere Resin GP cartridge for extraction. Analytes were separated on a Waters Xterra C18 column and quantified by liquid chromatography with tandem mass spectrometry using the multiple reaction monitoring mode. The whole procedure was automatic, and the total run time was 21 min. The limit of detection was in the range of 0.05–0.1 ng/mL for all analytes. The linearity ranged from 0.25 to 250 ng/mL for oxazepam, and 0.1 to 100 ng/mL for the other five analytes. Intraday and interday precision for all analytes was 0.6–12.8 and 1.0–9.2%, respectively. Accuracy ranged from 95.6 to 114.7%. Method recoveries were in the range of 65.1–80.8%. This method was fully automated, simple, and sensitive. Authentic oral fluid samples collected from two volunteers after consuming a single oral dose of 10 mg diazepam were analyzed to demonstrate the applicability of this method.  相似文献   

12.
    
An automated online solid‐phase extraction with restricted‐access material combined with high‐performance liquid chromatography and tandem mass spectrometry was developed and validated for the simultaneous quantification of vanillin and its vanillic acid metabolite in human plasma. After protein precipitation by methanol, which contained the internal standards, the supernatant of plasma samples was injected to the system, the endogenous large molecules were flushed out, and target analytes were trapped and enriched on the adsorbent, resulting in a minimization of sample complexity and ion suppression effects. Calibration curves were linear over the concentrations of 5–1000 ng/mL for vanillin and 10–5000 ng/mL for vanillic acid with a coefficient of determination >0.999 for the determined compounds. The lower limits of quantification of vanillin and vanillic acid were 5.0 and 10.0 ng/mL, respectively. The intra‐ and inter‐run precisions expressed as the relative standard deviation were 2.6–8.6 and 3.2–10.2%, respectively, and the accuracies expressed as the relative error were in the range of –6.1 to 7.3%. Extraction recoveries of analytes were between 89.5 and 97.4%. There was no notable matrix effect for any analyte concentration. The developed method was proved to be sensitive, repeatable, and accurate for the quantification of vanillin and its vanillic acid metabolite in human plasma.  相似文献   

13.
    
In this study, an innovative approach is proposed to predict the contribution of sixteen polycyclic aromatic hydrocarbons in barbecue smoke based on magnetic solid‐phase extraction system and gas chromatography‐mass spectrometry. In order to improve the detection limit of gas chromatography‐mass spectrometry, a kinds of magnetic nanomaterial synthesized previously was used as a sorbent in magnetic solid‐phase extraction. The recoveries ranged from 73.4% to 90.7%, and the limits of detection and limits of quantification were in the range 1.2‐5.4 ng·L−1 and 3.7‐16.4 ng·L−1 respectively. The method was successfully applied to the analysis of polycyclic aromatic hydrocarbons in smoke of the pork belly. The developed method could be potentially used for the assessing of polycyclic aromatic hydrocarbons profiles in environment pollution.  相似文献   

14.
A rapid method has been developed to analyse morphine, codeine, morphine-3-glucuronide, 6-monoacetylmorphine, cocaine, benzoylegonine, buprenorphine, dihydrocodeine, cocaethylene, 3,4-methylenedioxyamphetamine, ketamine, 3,4-methylenedioxymethamphetamine, pseudoephedrine, lignocaine, benzylpiperazine, methamphetamine, amphetamine, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine and methadone in human urine. Urine samples were diluted with methanol:water (1:1, v/v) and sample aliquots were analysed by hybrid linear ion trap-triple quadrupole mass spectrometry with a runtime of 12.5 min. Multiple reaction monitoring (MRM) as survey scan and an enhanced product ion (EPI) scan as dependent scan were performed in an information-dependent acquisition (IDA) experiment. Finally, drug identification and confirmation was carried out by library search with a developed in-house MS/MS library based on EPI spectra at a collision energy spread of 35 ± 15 in positive mode and MRM ratios. The method was validated in urine, according to the criteria defined in Commission Decision 2002/657/EC. At least two MRM transitions for each substance were monitored in addition to EPI spectra and deuterated analytes were used as internal standards for quantitation. The reporting level was 0.05 μg mL−1 for the range of analytes tested. The regression coefficients (r2) for the calibration curves (0–4 μg mL−1) in the study were ≥0.98. The method proved to be simple and time efficient and was implemented as an analytical strategy for the illicit drug monitoring of opioids, cocaines and amphetamines in criminal samples from crime offenders, abusers or victims in the Republic of Ireland. To the best of our knowledge there are no hybrid LC–MS applications using MRM mode and product ion spectra in the linear ion trap mode for opioids, cocaines or amphetamines with validation data in urine.  相似文献   

15.
    
A hydrophilic interaction chromatography (HILIC) and reverse‐phase liquid chromatography (RPLC) coupled with electrospray TOF MS method was developed for the analysis and characterization of constituents in the radix of Cyathula officinalis Kuan. Separation parameters of HILIC such as buffer pH, mobile phase strength, and organic modifier were evaluated. Fructose, glucose, and sucrose were identified by HILIC‐ESI/TOF MS. Reverse‐phase liquid chromatography‐ESI/TOF MS were applied for quick and sensitive identification of major saponins in Cyathula officinalis. In‐source collision‐induced dissociation has been performed to elucidate the fragmentation pathways of oleanane‐, hederagenin‐, and gypsogmin‐type saponins. Twelve saponins were characterized in this plant for the first time, and four of them were presumed to be new compounds. In addition, one phytoecdysteroid (cyasterone) and one coumarin (6,7‐dimethoxycoumarin) were detected at the same time. The present method was capable of rapid characterizing and providing structure information of constituents from herbal drugs.  相似文献   

16.
    
Pesticides, widely applied in agriculture, can produce a variety of transformation products and their continuous use causes deleterious effects to ecosystem. Efficient and sensitive analytical techniques for enrichment and analysis of pesticides samples are highly required. Compared with other extraction methods, solid‐phase micro extraction is a solvent free, cost effective, robust, versatile, and high throughput sample preparation technique, especially for the analysis of pesticides from complicated matrices. Coupling of solid‐phase micro extraction with gas chromatography and mass spectrometry and liquid chromatography–mass spectrometry has been extensively applied in pesticide analysis. On the other hand, in recent years, combination of fast separation using solid‐phase micro extraction and rapid detection using ambient mass spectrometry is providing highly efficient pesticide screening. This article summarizes the applications of solid‐phase micro extraction coupled to mass spectrometry for pesticides analysis.  相似文献   

17.
    
A simple, selective, and accurate ultra‐high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method was established and validated for the efficient separation and quantification of polyurethane amine catalysts in polyether polyols. Amine catalysts were primarily separated in polyether polyol‐based sample by solid‐phase extraction, and further baseline separated on a reversed‐phase/cation‐exchange mixed‐mode column (SiELC Primesep™ 200) using 0.1% trifluoroacetic acid/acetonitrile as a mobile phase in gradient elution mode at a flow rate of 0.2 mL/min. High‐resolution quadrupole time‐of‐flight mass spectrometry analysis in electrospray ionization positive mode allowed the identification as N,N′‐bis[3‐(dimethylamino)propyl]urea, N‐[2‐(2‐dimethylaminoethoxy)ethyl]‐N‐methyl‐1,3‐propanediamine, and N,N,N′,N′‐tetramethyldipropylenetriamine. The method was validated and presented good linearity for all the analytes in blank matrices within the concentration range of 0.20–5.0 or 0.1–2.0 μg/mL with the correlation coefficients (R2) ranging from 0.986 to 0.997. Method recovery ranged within 81–105% at all three levels (80, 100, and 120% of the original amount) with relative standard deviations of 1.0–6.2%. The limits of detection were in the range of 0.007–0.051 μg/mL. Good precision was obtained with relative standard deviation below 3.2 and 0.72% for peak area and retention time of three amines, respectively.  相似文献   

18.
建立了血液中氯硝西泮及其代谢产物7-氨基氯硝西泮的自动固相萃取/液相色谱-串联质谱（ASPE/LC-MS/MS）分析方法。样品经C18固相萃取柱提取后,采用LC-MS/MS进行测定,外标法定量。在WatersAtlantisTMdC18反相柱上分离,梯度洗脱,流动相为甲醇和0.1%甲酸水溶液,质谱采集为电喷雾正离子多反应监测模式。2种目标物在2~1000μg/L范围内具有良好的线性关系,相关系数为0.9959~0.9982,检出限为0.2~0.5μg/L;加标水平为50,200,1000μg/L时,方法的回收率为72.6%~96.3%,相对标准偏差为4.2%~10.3%。本方法可用于法庭与临床的毒物分析。  相似文献   

19.
    
A novel capillary zone electrophoresis separation coupled to electro spray ionization time‐of‐flight mass spectrometry method was developed for the simultaneous analysis of six toxic alkaloids: brucine, strychnine, atropine sulfate, anisodamine hydrobromide, scopolamine hydrobromide and anisodine hydrobromide in human plasma and urine. To obtain optimal sensitivity, a solid‐phase extraction method using Oasis MCX cartridges (1 mL, 30 mg; Waters, USA) for the pretreatment of samples was used. All compounds were separated by capillary zone electrophoresis at 25 kV within 12 min in an uncoated fused‐silica capillary of 75 μm id × 100 cm and were detected by time‐of‐flight mass spectrometry. This method was validated with regard to precision, accuracy, sensitivity, linear range, limit of detection (LOD), and limit of quantification (LOQ). In the plasma and urine samples, the linear calibration curves were obtained over the range of 0.50–100 ng/mL. The LOD and LOQ were 0.2–0.5 ng/mL and 0.5–1.0 ng/mL, respectively. The intra‐ and interday precision was better than 12% and 13%, respectively. Electrophoretic peaks could be identified by mass analysis.  相似文献   

20.
建立了超高效液相色谱-四极杆-飞行时间质谱法（UHPLC-Q-TOF-MS）快速筛查动物组织中7种β-受体激动剂残留（特布他林、沙丁胺醇、塞布特罗、莱克多巴胺、克伦特罗、溴布特罗、马布特罗）的检测方法。样品经乙酸铵提取,固相萃取净化后,进行UHPLC-Q-TOF-MS测定。根据分析软件,通过理论精确相对分子质量与所测得的精确相对分子质量之间匹配度,以及目标化合物的元素组成分析,结合保留时间、同位素丰度模型和子离子特征,对目标化合物进行确证。结果表明：7种β-受体激动剂在4个加标水平的加标回收率为75%~114%,RSD为4.5%~20.6%。该方法的相关系数（r2）为0.9914~0.9999,除克伦特罗的线性范围为0.4~40.0μg/kg,定量下限为0.4μg/kg外,其余化合物的线性范围均为0.2~40.0μg/kg,定量下限为0.2μg/kg。  相似文献   

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