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Journal of chromatography最新文献

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Rapid synthesis of isoprenoid diphosphates and their isolation in one step using either thin layer or flash chromatography. 用薄层或闪蒸色谱法一步快速合成类异戊二烯二磷酸及其分离。
Journal of chromatography Pub Date : 1993-08-13 DOI: 10.1016/0021-9673(93)80630-q
R K Keller, R Thompson
{"title":"Rapid synthesis of isoprenoid diphosphates and their isolation in one step using either thin layer or flash chromatography.","authors":"R K Keller,&nbsp;R Thompson","doi":"10.1016/0021-9673(93)80630-q","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80630-q","url":null,"abstract":"<p><p>A rapid procedure for the preparation of short-chain (C s-C.) isoprenoid diphosphates is described . It is based on the method of Cornforth and Popjak [Methods Enzymol., 15 (1969) 359-390] which utilizes bis-triethylammonium phosphate in trichioroacetonitriie as the phosphorylating reagent . The reaction takes place in 15 min, and product isolation, previously requiring several steps, is done in a single step using either preparative thin-layer chromatography or flash chromatography on silica . From a single TLC plate, up to 50 μ mol of pure farnesyl diphosphate (i .e., ca. 20 mg) can be isolated, while up to 1200 μ mol can be isolated using a standard flash chromatography column.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":" ","pages":"161-7"},"PeriodicalIF":0.0,"publicationDate":"1993-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80630-q","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31575063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 57
Characterization of vitamin D3 metabolites using continuous-flow fast atom bombardment tandem mass spectrometry and high-performance liquid chromatography. 使用连续流快速原子轰击串联质谱法和高效液相色谱法表征维生素D3代谢物。
Journal of chromatography Pub Date : 1993-08-13 DOI: 10.1016/0021-9673(93)80625-i
B Yeung, P Vouros, G S Reddy
{"title":"Characterization of vitamin D3 metabolites using continuous-flow fast atom bombardment tandem mass spectrometry and high-performance liquid chromatography.","authors":"B Yeung,&nbsp;P Vouros,&nbsp;G S Reddy","doi":"10.1016/0021-9673(93)80625-i","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80625-i","url":null,"abstract":"<p><p>A mass spectrometric method for the detection of vitamin D3 metabolites is described. This method involves the derivatization of the metabolites by cycloaddition with 4-phenyl-1,2,4-triazoline-3,5-dione, followed by their characterization by continuous-flow fast atom bombardment (CF-FAB) tandem mass spectrometry (MS-MS) and high-performance liquid chromatography (HPLC). Using HPLC, this derivatization has been shown to increase the UV detectability of 25-hydroxyvitamin D3 by about 5-fold. The FAB spectra of the adducts are dominated by peaks corresponding to a protonated molecule and a fragment ion derived in part from the loss of the side chain. Multiple reaction monitoring (MRM) of this transition by MS-MS may be utilized for trace level analysis of vitamin D metabolites. Sample introduction by flow injection yields detection limits in the low nanogram to high picogram range, whereas the use of on-line capillary LC has been found to decrease the detection limits to the low picogram level.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"645 1","pages":"115-23"},"PeriodicalIF":0.0,"publicationDate":"1993-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80625-i","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19392201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 39
Determination of pesticides in drinking water by on-line solid-phase disk extraction followed by various liquid chromatographic systems. 在线固相圆盘萃取-液相色谱法测定饮用水中的农药。
Journal of chromatography Pub Date : 1993-08-13 DOI: 10.1016/0021-9673(93)80626-j
S Chiron, D Barceló
{"title":"Determination of pesticides in drinking water by on-line solid-phase disk extraction followed by various liquid chromatographic systems.","authors":"S Chiron,&nbsp;D Barceló","doi":"10.1016/0021-9673(93)80626-j","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80626-j","url":null,"abstract":"<p><p>C-18 Empore extraction disks were coupled on-line with liquid chromatography-rapid scanning UV-VIS detection and post-column fluorescence detection for the isolation and trace enrichment of various pesticides [carbamates, (aldicarb, carbofuran, carbaryl), carbamate transformation products (TPs) (aldicarb sulfoxide, aldicarb sulfone, 3-hydroxycarbofuran, 3-hydroxy-7-phenol carbofuran, 3-keto-carbofuranphenol and 3-ketocarbofuran) and herbicides (chlortoluron, isoproturon and metolachlor)] spiked at concentration levels of 0.2 and 5 micrograms/l in drinking water samples. Recoveries were dependent on the pesticide level and preconcentrated water volume (50 ml to 1000 ml) using LC with rapid scanning UV-VIS detection. The same on-line system coupled with LC-post-column derivatization fluorescence detection has needed only 10 ml of water to achieve similar levels of determination for the carbamate insecticides.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"645 1","pages":"125-34"},"PeriodicalIF":0.0,"publicationDate":"1993-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80626-j","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19392202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 77
Displacement chromatography on cyclodextrin silicas. IV. Separation of the enantiomers of ibuprofen. 环糊精二氧化硅的置换色谱法。IV.布洛芬对映体的分离。
Journal of chromatography Pub Date : 1993-08-13 DOI: 10.1016/0021-9673(93)80618-i
G Farkas, L H Irgens, G Quintero, M D Beeson, A al-Saeed, G Vigh
{"title":"Displacement chromatography on cyclodextrin silicas. IV. Separation of the enantiomers of ibuprofen.","authors":"G Farkas,&nbsp;L H Irgens,&nbsp;G Quintero,&nbsp;M D Beeson,&nbsp;A al-Saeed,&nbsp;G Vigh","doi":"10.1016/0021-9673(93)80618-i","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80618-i","url":null,"abstract":"<p><p>A displacement chromatographic method has been developed for the preparative separation of the enantiomers of ibuprofen using a beta-cyclodextrin silica stationary phase. The retention behavior of ibuprofen was studied in detail: the log k' vs. polar organic modifier concentration, the log k' vs. pH, the log k' vs. buffer concentration and the log k' vs. 1/T relationships; also, the alpha vs. polar organic modifier concentration, the alpha vs. pH, the alpha vs. buffer concentration and the log alpha vs. 1/T relationships have been determined in order to find the carrier solution composition which results in maximum chiral selectivity and sufficient, but not excessive solute retention (1 < k' < 30). 4-tert.-Butylcyclohexanol, a structurally similar but more retained compound than ibuprofen, was selected as displacer for the separation. Even with an alpha value as small as 1.08, good preparative chiral separations were observed both in the displacement mode and in the overloaded elution mode, up to a sample load of 0.5 mg.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"645 1","pages":"67-74"},"PeriodicalIF":0.0,"publicationDate":"1993-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80618-i","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19392205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 20
Observation of a conformational effect in peptide molecule by reversed-phase high-performance liquid chromatography. 用反相高效液相色谱法观察肽分子的构象效应。
Journal of chromatography Pub Date : 1993-08-06 DOI: 10.1016/0021-9673(93)80710-p
M Lebl
{"title":"Observation of a conformational effect in peptide molecule by reversed-phase high-performance liquid chromatography.","authors":"M Lebl","doi":"10.1016/0021-9673(93)80710-p","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80710-p","url":null,"abstract":"<p><p>RP-HPLC of analogues of oxytocin containing a reduced peptide bond was studied using various columns and buffers. Anomalous behavior of one analogue served as a basis for the discussion of possible conformational consequences of this substitution.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 2","pages":"285-7"},"PeriodicalIF":0.0,"publicationDate":"1993-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80710-p","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19393523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Studies on new cross-axis coil planet centrifuge for performing counter-current chromatography. III. Speculations on the hydrodynamic mechanism in stationary phase retention. 反流式色谱用新型交叉轴线圈行星离心机的研究。3关于固定相保留的水动力机制的推测。
Journal of chromatography Pub Date : 1993-08-06 DOI: 10.1016/0021-9673(93)80705-d
J M Menet, K Shinomiya, Y Ito
{"title":"Studies on new cross-axis coil planet centrifuge for performing counter-current chromatography. III. Speculations on the hydrodynamic mechanism in stationary phase retention.","authors":"J M Menet,&nbsp;K Shinomiya,&nbsp;Y Ito","doi":"10.1016/0021-9673(93)80705-d","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80705-d","url":null,"abstract":"<p><p>Retention of the stationary phases of one organic-aqueous solvent system and three aqueous-aqueous polymer solvent systems was investigated on a cross-axis coil planet centrifuge. A graphic statistical treatment of all the data highlighted the prevailing effect of the inward-outward elution mode. A simplified model was proposed and studies on the paths and accelerations of cross-axis devices described in the previous paper provided explanations about the observed hydrodynamic behaviors.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 2","pages":"239-52"},"PeriodicalIF":0.0,"publicationDate":"1993-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80705-d","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19393522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Studies on a new cross-axis coil planet centrifuge for performing counter-current chromatography. II. Path and acceleration of coils and comparison with type J coil planet centrifuge. 反流式色谱用新型交叉轴线圈行星离心机的研究。2线圈轨迹、加速度及与J型行星离心机的比较。
Journal of chromatography Pub Date : 1993-08-06 DOI: 10.1016/0021-9673(93)80704-c
J M Menet, Y Ito
{"title":"Studies on a new cross-axis coil planet centrifuge for performing counter-current chromatography. II. Path and acceleration of coils and comparison with type J coil planet centrifuge.","authors":"J M Menet,&nbsp;Y Ito","doi":"10.1016/0021-9673(93)80704-c","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80704-c","url":null,"abstract":"<p><p>A comprehensive approach is introduced using parametric equations to describe the motion induced by type J and cross-axis type coil planet centrifuges. The plots of a line parallel to the coil axis are given. The centrifugal forces are then analyzed in two ways. Three-dimensional graphs show their geometry and the relative intensity of the lateral component is compared to that of the perpendicular component. This allowed a better understanding of the differences in paths and acceleration fields induced by the two types of counter-current chromatography devices.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 2","pages":"231-8"},"PeriodicalIF":0.0,"publicationDate":"1993-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80704-c","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19393521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
Analysis of paralytic shellfish poisoning toxins by automated pre-column oxidation and microcolumn liquid chromatography with fluorescence detection. 全自动柱前氧化-微柱液相色谱荧光检测分析麻痹性贝类中毒毒素。
Journal of chromatography Pub Date : 1993-08-06 DOI: 10.1016/0021-9673(93)80715-k
M Janecek, M A Quilliam, J F Lawrence
{"title":"Analysis of paralytic shellfish poisoning toxins by automated pre-column oxidation and microcolumn liquid chromatography with fluorescence detection.","authors":"M Janecek,&nbsp;M A Quilliam,&nbsp;J F Lawrence","doi":"10.1016/0021-9673(93)80715-k","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80715-k","url":null,"abstract":"<p><p>Periodate oxidation of the toxins responsible for paralytic shellfish poisoning (PSP) yields fluorescent purines suitable for trace analysis by reversed-phase LC. Mobile phases containing perfluorinated acids, such as heptafluorobutyric acid, as ion-pair agents were found to provide high capacity factors for the oxidized products. Gradient elution on a microbore column with large volume injections and fluorescence detection permitted the detection of femtomole quantities of PSP toxins. A fully automated pre-column oxidation procedure was developed for an LC autosampler system in order to improve precision and allow unattended analyses. The complete method was applied successfully to various samples, including shellfish and toxic phytoplankton.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 2","pages":"321-31"},"PeriodicalIF":0.0,"publicationDate":"1993-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80715-k","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19393524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 19
Studies on a new cross-axis coil planet centrifuge for performing counter-current chromatography. I. Design of the apparatus, retention of the stationary phase, and efficiency in the separation of proteins with polymer phase systems. 反流式色谱用新型交叉轴线圈行星离心机的研究。1 .仪器的设计，固定相的保留，以及用聚合物相系统分离蛋白质的效率。
Journal of chromatography Pub Date : 1993-08-06 DOI: 10.1016/0021-9673(93)80703-b
K Shinomiya, J M Menet, H M Fales, Y Ito
{"title":"Studies on a new cross-axis coil planet centrifuge for performing counter-current chromatography. I. Design of the apparatus, retention of the stationary phase, and efficiency in the separation of proteins with polymer phase systems.","authors":"K Shinomiya,&nbsp;J M Menet,&nbsp;H M Fales,&nbsp;Y Ito","doi":"10.1016/0021-9673(93)80703-b","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80703-b","url":null,"abstract":"<p><p>An improved model of the cross-axis synchronous flow-through coil planet centrifuge has been designed in light of previous studies. The apparatus has a versatile feature in that both analytical and preparative columns can be accommodated in both off-center and central positions. Each has merit in separations. Retention of stationary phase was examined with various two-phase solvent systems used for the separation of biopolymers. Both analytical and preparative columns showed satisfactory retention of the stationary phase under optimum conditions. The apparatus was evaluated in separation of a set of protein samples using a polyethylene glycol-potassium phosphate biphasic system. In both types of columns all proteins were resolved with partition efficiencies of 260 to 670 theoretical plates. Further studies indicated that the relatively low partition efficiency of proteins is mainly attributed to their high molecular mass or molecular heterogeneity within each species rather than due to the high viscosity of the polymer phase system.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 2","pages":"215-29"},"PeriodicalIF":0.0,"publicationDate":"1993-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80703-b","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19393520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 50
Determination of ionic species formed during growth of Escherichia coli by capillary isotachophoresis. 毛细管等速电泳法测定大肠杆菌生长过程中形成的离子种类。
Journal of chromatography Pub Date : 1993-08-06 DOI: 10.1016/0021-9673(93)80724-m
K Futschik, M Ammann, S Bachmayer, E Kenndler
{"title":"Determination of ionic species formed during growth of Escherichia coli by capillary isotachophoresis.","authors":"K Futschik,&nbsp;M Ammann,&nbsp;S Bachmayer,&nbsp;E Kenndler","doi":"10.1016/0021-9673(93)80724-m","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80724-m","url":null,"abstract":"<p><p>The ionic species that are formed during the microbial growth of Escherichia coli were determined by capillary isotachophoresis as a function of the time of cultivation. This formation was indicated by the change in a sum parameter, the impedance of the nutrient broth, measured by a special electrode system. Based on the determination of the individual ions formed under the given conditions (identified as acetate, lactate, alpha-ketoglutarate, fumarate, ammonium and probably a simple amine), the change in conductivity was calculated and compared with that obtained by the impedance measurement of the bulk medium. From the results it can be concluded that the change in the sum parameter as a function of time is originated by the ions determined.</p>","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 2","pages":"389-95"},"PeriodicalIF":0.0,"publicationDate":"1993-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80724-m","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19393525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
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