共查询到19条相似文献,搜索用时 352 毫秒
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苏莉 《理化检验(化学分册)》2006,42(10):793-795
采用高效液相色谱法对高效除草剂盖草能的中间体2-氯-5-三氯甲基吡啶(TCMP)及相关化合物的分析条件进行了探讨和优化。使用Zorbax eclipse XDB-C18色谱柱,以乙腈-水(30+70,体积比)为流动相,控制流速1 mL.min-1,采用紫外可变波长检测器,检测波长为240 nm,方法的线性关系良好,相关系数为0.998 4,回收率为99.05%。在实样分析中同时测定了合成TCMP过程中的两个主要副产物2-氯-5-氯甲基吡啶和2-氯-3-三氯甲基吡啶。 相似文献
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以2-氯-3-硝基-5-溴吡啶为起始原料,经取代反应、水解反应、Suzuki偶联反应得到6-甲基-5-硝基-3-吡啶硼酸频哪酯。反应总收率为51%,中间体及目标产物结构由IR和1H-NMR表征。 相似文献
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以卤代吡啶为起始原料与水合肼反应合成肼基吡啶衍生物中间体,该中间体进一步与2,4-戊二酮关环合成了一类新型1-吡啶基-3,5-二甲基吡唑衍生物。对合成目标化合物进行了质谱、核磁表征。并且采用X射线单晶衍射分析方法进一步测定了目标化合物1-(3,5,6-三氯吡啶-2-基)-3,5-二甲基-1氢吡唑(3f)的晶体结构。 相似文献
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含4-噻唑啉酮环的新烟碱类化合物的合成及生物活性 总被引:1,自引:0,他引:1
根据生物等排原理和新烟碱类化合物与乙酰胆碱酯酶的作用机理, 以4-噻唑啉酮(4)为中间体设计合成了2-取代-3-(2-氯-5-吡啶亚甲基)-4-氰基亚胺基-1,3-噻唑烷(8a~8c)和5-芳基次甲基-2-芳基-3-(2-氯-5-吡啶亚甲基)-4-噻唑啉酮(5a~5e)两类化合物. 中间体(4)由醛、胺和巯基乙酸缩合得到. 所有化合物的结构均经元素分析和1H NMR确证. 初步生物活性试验结果表明, 部分化合物具有一定的杀菌活性和促进黄瓜子叶生根活性, 化合物8b显示出很好的抗HIV-1蛋白酶活性. 相似文献
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建立了粮食作物中三氯甲基吡啶及其代谢物6-氯吡啶甲酸的衍生化-气相色谱-三重四极杆质谱(GC-MS/MS)检测方法。选取高粱、小麦、玉米及爆谷等典型的粮食作物,采用酸性乙腈提取,以浓硫酸作为三氯甲基吡啶代谢物的衍生化试剂,优化了衍生化反应的最佳反应条件,并使用GC-MS/MS分析,以内标法对三氯甲基吡啶及其代谢物进行定量检测。结果表明,在0.025~0.4 mg/L范围内,线性关系良好,相关系数(r2)均大于0.995,在3个不同添加水平下的平均回收率在80.4%~98.4%之间,相对标准偏差(RSD)在1.0%~10.1%之间。该方法操作简单、高效,灵敏度高,抗干扰能力强,回收率和重复性良好,能够满足粮食作物中三氯甲基吡啶及其代谢产物残留量的检测要求。 相似文献
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Alfazema LN Richards DS Gélébart S Mitchell JC Snowden MJ 《European journal of mass spectrometry (Chichester, England)》2005,11(4):393-402
We have developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) system capable of achieving better than 2% accuracy, routinely over a wide concentration range of 1800 ng mL-1. We demonstrate that the necessary high precision, high accuracy and rapid analysis can be achieved using LC-MS/MS technology. Automated nanoelectrospray ionisation tandem mass spectrometry (nanoESI-MS/MS) technology can be employed to eliminate the chromatographic step completely. In this paper, nanoESI-MS/MS is evaluated and compared directly with LC-MS/MS for the quantitative analysis of two-test analytes, amitriptyline (ATT) and 5-methoxytryptamine (5-MTT), in aqueous/organic mixture. Calibration curves were found to be linear over a wide concentration range of 1800 ng mL-1 for both analytes using LC-MS/MS. Using nanoESI-MS/MS ATT gave a linear response while 5-MTT gave a non-linear response using nanoESI-MS/MS over the same concentration range as in LC-MS/MS. Accuracy and precision values of quality control samples (QCs) at four concentration levels were analysed in replicates of six at each level using 5-MTT and ATT as test analytes for both techniques. The LC-MS/MS system was capable of achieving accuracy levels of 99.50101.96% for ATT and 100.17100.40% for 5-MTT. Accuracy levels using nanoESI-MS/MS were not comparable to LC-MS/MS, they ranged from 90.09100.18% for ATT and 95.95113.55% for 5-MTT. The precision values obtained for nanoESI-MS/MS were in good agreement with those obtained by LC-MS/MS. 相似文献
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Determination of ink photoinitiators in packaged beverages by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry 总被引:2,自引:0,他引:2
Sagratini G Caprioli G Cristalli G Giardiná D Ricciutelli M Volpini R Zuo Y Vittori S 《Journal of chromatography. A》2008,1194(2):213-220
A new analytical method, using gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) techniques, was developed for the determination in packaged food beverages of five ink photoinitiator residues: 2-isopropylthioxanthone (ITX), benzophenone, 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB), 1-hydroxycyclohexyl-1-phenyl ketone (IRGACURE 184) and ethyl-4-dimethylaminobenzoate (EDAB). Samples were extracted from selected beverages (milk, fruit juices and wine) and relative packagings, using n-hexane and dichloromethane, respectively, purified on solid-phase extraction (SPE) silica gel cartridges, and then analyzed in GC/MS and LC/MS. The recovery percentages, obtained spiking the beverage samples at concentrations of 4 and 10 microgl(-1) with a standard mixture of photoinitiators, were in the range 42-108% (milk), 50-84% (wine), and 48-109% (fruit juices). The repeatability of the method was assessed in all cases by the % of correlation value, that was lower than 19%. The lowest limits of detection (LODs) and limits of quantification (LOQs), obtained using GC/MS, were in the range 0.2-1 and 1-5 microgl(-1), respectively. The method was applied to the analysis of forty packaged food beverages (milk, fruit juices and wine samples). The most significant contamination was that of benzophenone, found in all samples in a concentration range of 5-217mugl(-1). Its presence was confirmed by an LC/Atmospheric-Pressure PhotoIonization (APPI)/MS/MS analysis. The photoinitiator (EHDAB) was found in eleven out of forty beverages in a concentration range of 0.13-0.8 microgl(-1). Less important was the ITX contamination, found in three out of forty samples in a range 0.2-0.24 microgl(-1). The work proposes a new method to analyze ink photoinitiator residues in polycoupled carton packaging and in contained food beverages. 相似文献
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The paper presents a novel strategy to identify analytical markers of traditional Chinese medicine preparation (TCMP) rapidly via direct analysis in real time mass spectrometry (DART-MS). A commonly used TCMP, Danshen injection, was employed as a model. The optimal analysis conditions were achieved by measuring the contribution of various experimental parameters to the mass spectra. Salvianolic acids and saccharides were simultaneously determined within a single 1-min DART-MS run. Furthermore, spectra of Danshen injections supplied by five manufacturers were processed with principal component analysis (PCA). Obvious clustering was observed in the PCA score plot, and candidate markers were recognized from the contribution plots of PCA. The suitability of potential markers was then confirmed by contrasting with the results of traditional analysis methods. Using this strategy, fructose, glucose, sucrose, protocatechuic aldehyde and salvianolic acid A were rapidly identified as the markers of Danshen injections. The combination of DART-MS with PCA provides a reliable approach to the identification of analytical markers for quality control of TCMP. 相似文献
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水果中三唑酮残留量的气相色谱和气相色谱—质谱分析 总被引:10,自引:0,他引:10
水果中三唑酮残留用丙酮提取,经液-液分配净化,用气相色谱-电子捕获检测器测定,并用相色谱-质谱进行确证以HP-5大口径毛细管柱和HP-5MS毛细管柱为分离柱,选择出合适的色谱条件。三唑酮的分离效果良好。 相似文献
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Camera E Picardo M Presutti C Catarcini P Fanali S 《Journal of separation science》2004,27(12):971-976
We developed a simple and reliable analytical method for the quantification and the characterization of ceramides extracted from biological samples by high-performance liquid chromatography (HPLC) coupled to electrospray ionisation tandem mass spectrometry (ESI/MS/MS). The chromatographic separation of analytes was carried out in a RP8 column, eluting with a methanol-water mixture in gradient elution mode. The separated lipids were detected by total ion monitoring and characterised by MS/MS spectra; quantitative analysis was performed by integrating the extracted ion peaks obtained in the negative ion mode. Good repeatability was obtained for retention time (0.3-2%), peak area ratio (A(S)/A(IS), 2-8%), as well as limit of detection (LOD, 5-26 pg) and quantification (LOQ, 13-53 pg). The method was validated for the analysis of N-palmitoyl-D-erythro-sphingosine (Cer16), N-stearoyl-D-erythro-sphingosine (Cer18), N-tetracosanoyl-D-erythro-sphingosine (N24:0, lignoceric ceramide, Cer24:0), and N-tetracos-15'-enoyl-D-erythro-sphingosine (N24:1, nervonic ceramide, Cer24:1), giving good results. Lipid mixtures, extracted from skin and epidermal cells, were analysed for their content of the studied ceramides. 相似文献
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Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QqTOF-MS) is an emerging technique offering more rapid and efficient separation, as well as the possibility to obtain accurate mass measurement and tandem mass spectrometry (MS/MS). This paper deals with the use of UPLC-QqTOF-MS to identify the pesticide residues present in complex pear extracts. Carbendazim, imazalil, and ethoxyquin were successfully identified because of the accurate mass determination of their protonated molecule and their major fragments in the product ion mass spectra. A few plastic and latex additives were also found, most of them probably coming from the packaging transfer to the fruits. The potential of the UPLC-QqTOF-MS and UPLC-QqTOF-MS/MS techniques as a quantification tool is also discussed taking imazalil as example. For quantification, calibration curves were linear over a dynamic range of 2 orders of magnitude, whereas higher calibration ranges are better adjusted to polynomial curves of second and third order. Quantification using different mass windows was also assessed. Accurate quantification required mass windows as wide as 20 mDa, narrower mass windows of 5 mDa provided erroneous quantification, probably because the low ion abundance. The mean recoveries and percentage relative standard deviation (RSD) of 35 determinations for imazalil were 76% (13% RSD) by MS and 77% (14% RSD) by MS/MS. The theoretical limit of detection was 0.4 microg kg(-1), with a validated limit of quantification of 2 microg kg(-1). The quantitative data obtained using UPLC-QqTOF-MS were compared with those obtained using conventional liquid chromatography (LC)-MS/MS with a triple quadrupole (QqQ). It was concluded that UPLC-QqTOF-MS might become a powerful analytical tool for both, unknown's identification and quantification of target pesticides. 相似文献
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A direct ultra-performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) for simultaneous measurement of urinary 5-hydroxytryptophol glucuronide (GTOL) and 5-hydroxyindoleacetic acid (5-HIAA) was developed. The GTOL/5-HIAA ratio is used as an alcohol biomarker with clinical and forensic applications. The method involved dilution of the urine sample with deuterated analogues (internal standards), reversed-phase chromatography with gradient elution, electrospray ionisation and monitoring of two product ions per analyte in selected reaction monitoring mode. The measuring ranges were 6.7-10 000 nmol/l for GTOL and 0.07-100 micromol/l for 5-HIAA. The intra- and inter-assay imprecision, expressed as the coefficient of variation, was below 7%. Influence from ion suppression was noted for both compounds but was compensated for by the use of co-eluting internal standards. The accuracy in analytical recovery of added substance to urine samples was 96 and 98%, respectively, for GTOL and 5-HIAA. Method comparison with GC-MS for GTOL in 25 authentic patient samples confirmed the accuracy of the method with a median ratio between methods (GC-MS to UPLC-MS/MS) of 1.14 (r(2) = 0.975). The difference is explained by the fact that the GC-MS method also measures unconjugated 5-hydroxytryptophol naturally present in urine. The comparison with data for 5-HIAA obtained by an HPLC method demonstrated a median ratio of 1.05 between the methods. The UPLC-MS/MS method was capable of measuring endogenous GTOL and 5-HIAA levels in urine, which agreed with the literature data. In conclusion, a fully validated and robust direct method for the routine measurement of urinary GTOL and 5-HIAA was developed. 相似文献
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Uchôa FD Palma EC Souza NF Lima MC Galdino SL Pitta IR Dalla Costa T 《Journal of AOAC International》2010,93(4):1215-1221
A rapid, sensitive, and simple HPLC/MS/MS method was developed and validated for the determination of (5Z,E)-3-[2-(4-chlorophenyl)-2-oxoethyl]-5-(1H-indol-3-ylmethylene)-thiazolidine-2, 4-dione (PG15) in rat plasma using chlortalidone as an internal standard (IS). Analyses were performed using a C18 column and isocratic elution with acetonitrile-water (90 + 10, v/v) containing 10 mM ammonium hydroxide (pH 8.0) as the mobile phase pumped at 0.3 mL/min. Detection was performed by MS with negative ion mode electrospray ionization. Rat plasma samples were prepared by deproteinizing with acetonitrile. Detected fragments were 395.1 > 171.9 for PG15 and 337.3 > 189.9 for the IS. Calibration curves were linear from 10 to 1000 ng/mL, with the determination coefficient > 0.99. The intraday and interday precisions were less than 12.2 and 11.3%, respectively. The applicability of the HPLC/MS/MS method for pharmacokinetic studies was tested using plasma samples obtained after oral administration of PG15 to rats, and it provided the necessary sensitivity, linearity, precision, accuracy, and specificity. 相似文献