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Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor 被引量:2
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作者 杨云梅 曹红翠 +1 位作者 徐哲荣 陈晓明 《Journal of Zhejiang University Science》 CSCD 2004年第6期738-742,共5页
Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart di... Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results:rHPLC is more convenient, sensitive,specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research. 展开更多
关键词 Platelet activating factor reversed phase high-performance liquid chromatographic technique Coronary heart disease Cerebral infarction
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INTERSECTION POINT RULE OF THE RETENTION VALUE AND MOBILE PHASE COMPOSITION OF THE HOMOLOGUES IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY 被引量:1
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作者 Fu An WANG Chang Sheng YANG +2 位作者 Yuan Li JIANG Deng Gao JIANG Da Zhuang LIU 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第11期907-910,共4页
Based on the intersection point rule of the retention value and normal boiling point of homologues in reversed-phase high-performance liquid chromatography(RPLC), the intersection point rule of the retention value of ... Based on the intersection point rule of the retention value and normal boiling point of homologues in reversed-phase high-performance liquid chromatography(RPLC), the intersection point rule of the retention value of homologues and mobile phase composition has been derived, and was testified by a lot of experimental data from the literature. With this newly proposed equation, we can use the retention value of the compound in one mobile phase composition to predict its retention value in any other mobile phase composition. For fourteen groups of homologues in five mobile phase compositions on five Kinds of columns, the overall average absolute error of 721 data sets is 2.8%. 展开更多
关键词 INTERSECTION POINT RULE OF THE RETENTION VALUE AND MOBILE phase COMPOSITION OF THE HOMOLOGUES IN reverseD-phase high-performance liquid chromatography
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A Sensitive Reversed-Phase High-Performance Liquid Chromatography Method for the Quantitative Determination of Milk Xanthine Oxidase Activity 被引量:1
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作者 Zhongqin Li Ruizhang Guan Hongwei Liu 《Open Journal of Medicinal Chemistry》 2013年第1期26-30,共5页
A new reversed-phase high performance liquid chromatography method was developed to quantitate the activity of xanthine oxidase involved in milk fat globule membrane with xanthine as the substrate and the separation o... A new reversed-phase high performance liquid chromatography method was developed to quantitate the activity of xanthine oxidase involved in milk fat globule membrane with xanthine as the substrate and the separation of product (uric acid). The increment of uric acid in the reaction system was used to calculate the total activity of XO. The optimized assay conditions, linearity of detection, recovery of uric acid and chromatogram were developed in text, indicating this method is simple, rapid and efficient. It is an alternative potential method for the determination of the activity of XO in milk. 展开更多
关键词 XANTHINE OXIDASE (XO) Enzyme Activity Assay reverseD-phase High Performance liquid chromatography (rp-hplc)
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Quantitative analysis by reversed-phase high-performance liquid chromatography and retinal neuroprotection after topical administration of moxonidine
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作者 Qian Zhang Mei-Fang Chu +5 位作者 Yan-Hong Li Chun-Hua Li Run-Jia Lei Si-Cen Wang Bao-Jun Xiao Jian-Gang Yang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2020年第3期390-398,共9页
AIM:To determine moxonidine in aqueous humor and iris-ciliary body by reversed-phase high performance liquid chromatography(RP-HPLC),and to evaluate the retinal neuroprotective effect after topical administration with... AIM:To determine moxonidine in aqueous humor and iris-ciliary body by reversed-phase high performance liquid chromatography(RP-HPLC),and to evaluate the retinal neuroprotective effect after topical administration with moxonidine in a high intraocular pressure(IOP)model.METHODS:The eyes of albino rabbits were administered topically and ipsilaterally with 0.2%moxonidine.A RPHPLC method was employed for the identification and quantification of moxonidine between 2 and 480 min,which presented in the aqueous humor and iris-ciliary body.Flash electroretinography(F-ERG)amplitude and superoxide dismutase(SOD)level were measured between day 1 and day 15 after topical administration with moxonidine in a rabbit model of high IOP.Histological and ultrastructural observation underwent to analyze the changes of retinal morphology,the inner retinal layers(IRL)thickness,and retinal ganglion cell(RGC)counting.RESULTS:Moxonidine was detectable between 2 and 480 min after administration,and the peak concentration developed both in the two tissues at 30 min,0.51μg/m Lin aqueous humor and 1.03μg/g in iris-ciliary body.In comparison to control,F-ERG b-wave amplitude in moxonidine eyes were significantly differences between day 3 and day 15(P<0.01)in the high IOP model;SOD levels were significantly higher at all time-points(P<0.01)with a maximum level of 20.29 U/mgprot at day 15;and RGCs were significantly higher(P<0.05).CONCLUSION:Moxonidine is a viable neuroprotective agent with application to high IOP model.All layers of retina,including RGC layer,retinal nerve fiber layer and INL,are more preserved after moxonidine administration.SOD plays a neuroprotective role in ocular hypertension-mediated RGC death. 展开更多
关键词 reverseD-phase high-performance liquid chromatography MOXONIDINE RETINAL GANGLION cell NEUROPROTECTION superoxide DISMUTASE
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Simultaneous Determination of Amlodipine with H<sub>1</sub>-Receptor Antagonists by Reversed Phase High Performance Liquid Chromatography and Application to Interaction Studies
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作者 Muhammad Saeed Arayne Najma Sultana +1 位作者 Saima Sher Bahadur Muhammad Nawaz 《American Journal of Analytical Chemistry》 2012年第9期632-637,共6页
A rapid, fast and precise method has been developed and validated for the simultaneous determination of amlodipine with H1-receptor antagonists (cetirizine, fexofenadine, and buclizine) from dosage forms. The chromato... A rapid, fast and precise method has been developed and validated for the simultaneous determination of amlodipine with H1-receptor antagonists (cetirizine, fexofenadine, and buclizine) from dosage forms. The chromatography was performed on a Purospher? Star, C18 (5 mm, 250 × 4.6 mm) column using acetonitrile: buffer (0.01 mM) (40:60, v/v, pH adjusted to 3.0), as a mobile phase. The mobile phase was pumped at a flow rate of 1.0 mL·min-1 and UV detection was performed at 240 nm. The method was validated for linearity, accuracy, precision and specificity. The method was applied to study the interaction between amlodipine and H1-receptor antagonists. These interactions were carried out in simulated gastric juice (pH 1), simulated full stomach (pH 4), blood pH (pH 7.4) and simulating GI (pH 9). The interacting drugs were heated at 37℃ with intermit-tent shaking and the samples were withdrawn every thirty minutes for three hours and drug contents were analyzed by RP-HPLC techniques. In most cases the in vitro availability of amlodipine was decreased. It was observed that the change in in vitro availability was pH dependent. 展开更多
关键词 AMLODIPINE CETIRIZINE FEXOFENADINE Buclizine INTERACTIONS reversed phase High Performance liquid chromatography
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Development of a Rapid and Efficient Liquid Chromatography Method for Determination of Gibberellin A4 in Plant Tissue, with Solid Phase Extraction for Purification and Quantification 被引量:1
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作者 Julia Medrano Macías Rahim Foroughbakhch Pournavab +1 位作者 Manuel Humberto Reyes-Valdés Adalberto Benavides-Mendoza 《American Journal of Plant Sciences》 2014年第5期573-583,共11页
A new, rapid and efficient reverse phase Liquid Chromatography (RP-LC) method was developed for determination of Gibberellin A4 (GA4) in samples of flower stalk of Dasylirion cedrosanum and vegetative tissue of Epithe... A new, rapid and efficient reverse phase Liquid Chromatography (RP-LC) method was developed for determination of Gibberellin A4 (GA4) in samples of flower stalk of Dasylirion cedrosanum and vegetative tissue of Epithelantha micromeris. Purification of GA4 was carried out by solid phase extraction (SPE), in Epithelantha micromeris. In the chromatography method was obtaining a retention time of 2.1 min, using Hypersil GOLD C-18 column (100 × 4.6 mm dim and size particle 5 μ), mobile phase 50/50 acetonitrile/water and a flow 1.0 ml/min. Detection was carried out by a UV detector set at 205 nm, and a quantization limit of 0.4 mg/L. The obtained correlation coefficient was 0.995. 展开更多
关键词 Dasyrilon cedrosanum Epithelantha micromeris PHYTOHORMONE Separation Plant Growth REGULATORS reverse phase liquid chromatography Solid phase Extraction
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A Stability Indicating Reverse Phase-HPLC Method Development and Validation for the Estimation of Rucaparib in Bulk and Pharmaceutical Dosage Form 被引量:1
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作者 D. Suchitra Satyanarayana Battu 《American Journal of Analytical Chemistry》 2021年第4期96-107,共12页
The research was carried out for establishing a new reverse phase-HPLC stability indicating method for the quantification of Rucaparib. The experiment was determined on Waters HPLC instrument using 996 photo-diode arr... The research was carried out for establishing a new reverse phase-HPLC stability indicating method for the quantification of Rucaparib. The experiment was determined on Waters HPLC instrument using 996 photo-diode array detector. The separation was done by using symmetry C-18 ODS (25 cm × 0.46 cm internal diameter) 5 μm analytical column containing mobile phase of Phosphate buffer (0.02 M) and methanol [65:35% v/v] adjusted pH to 4.8 by adding dilute ortho phosphoric acid. The method was run at 1 ml·min<sup>-1</sup> at 286 nm detection. The drug was eluted at 5.484 min. After developing the method, it was assured for the intended use by validation which was done according to ICH Q2B guidelines. The analytical parameters checked were linearity, accuracy, repeatability, intermediate precision, limit of detection, limit of quantitation, ruggedness and robustness. It was observed that the response of the detector was linear in the range of 6 - 14 μg/ml with correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability indicating assay method was established by using the samples generated by forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative and photolytic degradation and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the analysis of quality of the rucaparib drug. 展开更多
关键词 Rucaparib reverse-phase High Performance liquid chromatography Method Development VALIDATION
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Predicting a, c indices in reversed-phase high-performance liquid chromatography (RP-HPLC) from Kovats index in gas chromatography (GC)
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作者 Shi, W Liang, XM Lu, PZ 《Chinese Science Bulletin》 SCIE EI CAS 1997年第3期210-215,共6页
KOVATS index is the most precise index system reflecting the interaction between the molecules of solutes and stationary phase in gas chromatography at present. Large quantity of Kovats in dex data have been published... KOVATS index is the most precise index system reflecting the interaction between the molecules of solutes and stationary phase in gas chromatography at present. Large quantity of Kovats in dex data have been published. It is a good way to use Kováts index in gas chromatography to predict the retention value in liquid chromatography, which is significant in theory and apphcation. 展开更多
关键词 gas CHROMATOGRAPHIC RETENTION INDEX a c indices in reverseD-phase liquid chromatography prediction.
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A Stability Indicating Reverse Phase-HPLC Method Development and Validation for the Estimation of Bimatoprost 0.3% &Timolol 0.5% Pharmaceutical Ophthalmic Dosage Form
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作者 Md. S. Amin Muhammad T. Islam 《American Journal of Analytical Chemistry》 CAS 2022年第12期506-530,共25页
The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmi... The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min<sup>-1</sup> at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate. 展开更多
关键词 BIMATOPROST TIMOLOL reverse-phase High Performance liquid chromatography Method Development Validation Stability Indicating
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PEAK IDENTIFICATION FROM INTERACTION INDEX IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
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作者 陈农 张玉奎 卢佩章 《Science China Chemistry》 SCIE EI CAS 1992年第12期1425-1433,共9页
The interaction index c which was derived from the fundamental retention equationlogk’ =a + cC_B in reversed--phase high--performancc liquid chromatography (RP-HPLC) quan-titatively describes the difference in the in... The interaction index c which was derived from the fundamental retention equationlogk’ =a + cC_B in reversed--phase high--performancc liquid chromatography (RP-HPLC) quan-titatively describes the difference in the interaction between solute--strong. solvent andsolute--weak solvent; it has shown to be a constant for a specific solute even when columnsystems with different C18 packings are used. The theoretical basis for peak identificationby using interaction index has been proposed, which was based on the a,c values on stan-dard C18 column by utilizing linear a-a plots on column pairs and the linear relationship be-tween parameters a and c for the structural related compounds. Through the establishmentof parameters a,c data based on the standard C18 column for a certain type of compounds,the retention of thesc compounds on various C18 columns can be predicted. Typical exam-ples have been given to verify the correctness of this method. 展开更多
关键词 peak identification reverseD-phase high-performance liquid chromatography interaction INDEX c HYDROPHOBIC INDEX α LINEAR α-α PLOTS on column PAIRS LINEAR α-c relationship structural related compounds
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A liquid chromatography with tandem mass spectrometry method for quantitating total and unbound ceritinib in patient plasma and brain tumor 被引量:1
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作者 Xun Bao Jianmei Wu +1 位作者 Nader Sanai Jing Li 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2018年第1期20-26,共7页
A rapid, sensitive, and robust reversed-phase liquid chromatography with tandem mass spectrometry method was developed and validated for the determination of total and unbound ceritinib, a secondgeneration ALK inhibit... A rapid, sensitive, and robust reversed-phase liquid chromatography with tandem mass spectrometry method was developed and validated for the determination of total and unbound ceritinib, a secondgeneration ALK inhibitor, in patient plasma and brain tumor tissue samples. Sample preparation involved simple protein precipitation with acetonitrile. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C_(18) column using a 4-min gradient elution consisting of mobile phase A(0.1% formic acid in water) and mobile phase B(0.1% formic acid in acetonitrile), at a flow rate of 0.4 m L/min. Ceritinib and the internal standard([^(13)C_6]ceritinib) were monitored using multiple reaction monitoring mode under positive electrospray ionization. The lower limit of quantitation(LLOQ) was 1 n M of ceritinib in plasma. The calibration curve was linear over ceritinib concentration range of 1–2000 n M in plasma. The intra-and interday precision and accuracy were within the generally accepted criteria for bioanalytical method( o15%).The method was successfully applied to assess ceritinib brain tumor penetration, as assessed by the unbound drug brain concentration to unbound drug plasma concentration ratio, in patients with brain tumors. 展开更多
关键词 Ceritinib reverseD-phase liquid chromatography with tandem mass spectrometry (LC–MS/MS) FRACTION unbound in PLASMA FRACTION unbound in BRAIN tissue BRAIN tumor penetration Unbound brain-to-plasma partition coefficient
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RP-HPLC-ELSD法测定逍遥颗粒中柴胡皂苷c、a、d的含量
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作者 范洋 李明辉 +1 位作者 逯小萌 王丽霞 《中国食品药品监管》 2024年第8期138-145,共8页
目的:采用反相高效液相色谱-蒸发光散射检测(RP-HPLC-ELSD)法同时测定逍遥颗粒中柴胡皂苷c、a、d三种成分的含量。方法:采用安捷伦(Agilent)SB-C18色谱柱(4.6mm×250mm,5μm),流动相为乙腈(A)-水(B)。梯度洗脱程序为0~18min,30%A;18... 目的:采用反相高效液相色谱-蒸发光散射检测(RP-HPLC-ELSD)法同时测定逍遥颗粒中柴胡皂苷c、a、d三种成分的含量。方法:采用安捷伦(Agilent)SB-C18色谱柱(4.6mm×250mm,5μm),流动相为乙腈(A)-水(B)。梯度洗脱程序为0~18min,30%A;18~26min,35%~45%A;26~35min,45%~55%A。流速为1.0ml/min,柱温为30℃,气体流速为2.5L/min,蒸发温度为60℃,进样量为10μl。结果:柴胡皂苷c、a、d分别在0.950~19.000μg、1.088~21.760μg、1.520~30.400μg的范围内线性关系良好。柴胡皂苷c平均回收率为99.49%,RSD为0.35%(n=9);柴胡皂苷a平均回收率为99.99%,RSD为0.66%(n=9);柴胡皂苷d平均回收率为99.12%,RSD为0.47%(n=9)。结论:该方法准确、灵敏、重复性好,可作为逍遥颗粒中柴胡皂苷c、a、d的含量测定方法。 展开更多
关键词 逍遥颗粒 柴胡皂苷 反相高效液相色谱-蒸发光散射检测法 含量测定 质量控制
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Characters of the Plateau of Methanol Increment in Frontal Analysis in Reversed Phase Liquid Chromatography 被引量:4
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作者 耿信笃 弗莱德依瑞格涅尔 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2002年第5期431-440,共10页
With insulin methanol water, and the ion pairing agent, hydrochloric acid and trifluroacetic acid (TFA), the character of the first plateau (FP) on the elution curve of frontal analysis in reversed phase liquid chro... With insulin methanol water, and the ion pairing agent, hydrochloric acid and trifluroacetic acid (TFA), the character of the first plateau (FP) on the elution curve of frontal analysis in reversed phase liquid chromatography (RPLC) was investigated by on line UV spectrometry and identified with nuclear magnetic resonance (NMR) spectrometry and mass spectrometry. The profile of the FP is the same as that of a usual elution curve of methanol in frontal analysis (FA). When the insulin concentration was limited to a certain range, the height of the FP was found to be proportional to the insulin concentration in mobile phase and its length companying to shorten. The FP profile on the intersection of two tangents reflects the components of the microstructure in the depth direction of the bonded stationary phase layer and the desorption dynamics of the displaced components. The displaced methanol was quantitatively determined by NMR and on line UV spectrometries. TFA with high UV absorbance can not be used as an ion pairing agent for the investigation of the FP in RPLC, but it can be used as a good marker to investigate the complicated transfer process of components in the stationary phase in RPLC. A stoichiometric displacement process between solute and solvent was proved to be valid in both usual and FA in RPLC. From the point of view of dynamics of mass transfer, the solutes can only contact to the surface of stationary phase in usual RPLC, while solute can penetrate into it in FA of RPLC. The solvation of insulin in methanol and water solution as an example indicating the usage of the FP in the FA was also investigated in this paper. 展开更多
关键词 displacement mechanism frontal analysis ion pairing agent methanol increment partition mechanism reversed phase liquid chromatography
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A reversed phase/hydrophilic interaction/ion exchange mixed-mode stationary phase for liquid chromatography 被引量:1
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作者 Sainan Zhang Feifang Zhang +1 位作者 Bingcheng Yang Xinmiao Liang 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第2期470-472,共3页
A reversed phase (RP)/hydrophilic interaction (HILIC)/ion exchange (IEX) mixed tri-mode stationary phase (TMSP) has been prepared via a divergent synthesis scheme starting from propylamine on silica then by amine-epox... A reversed phase (RP)/hydrophilic interaction (HILIC)/ion exchange (IEX) mixed tri-mode stationary phase (TMSP) has been prepared via a divergent synthesis scheme starting from propylamine on silica then by amine-epoxy reactions with 1,4-butanedioldiglycidyl ether and tertiary amines (N,Ndimethyldecylamine, DMDA). Its retention mechanism was found to follow RP/HILIC/IEX mixed-mode.The stop-flow test revealed that TMSP had good compatibility with 100% aqueous mobile phase. It demonstrated effective separation towards several kinds of compounds or drug molecules and their counterions within a single run. 展开更多
关键词 MIXED-MODE Stationary phase reversed phase liquid chromatography HYDROPHILIC interaction liquid chromatography Ion exchange Drug molecules
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Highly sensitive detection of melamine based on reversed phase liquid chromatography mass spectrometry 被引量:7
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作者 WU QingQing FAN KeXin +3 位作者 SHA Wei RUAN HongQiang ZENG Rong SHIEH ChiaHui 《Chinese Science Bulletin》 SCIE EI CAS 2009年第5期732-737,共6页
In this work, we developed a highly sensitive method to detect melamine based on reversed phase liquid chromatography mass spectrometry. A mass spectrometry compatible ion pair, heptafluorobu-tyric acid(HFBA), was use... In this work, we developed a highly sensitive method to detect melamine based on reversed phase liquid chromatography mass spectrometry. A mass spectrometry compatible ion pair, heptafluorobu-tyric acid(HFBA), was used to separate melamine by reversed phase liquid chromatography prior to electrospray mass spectrometry. The incorporation of isotope internal standard and multiple reaction monitoring improved the accuracy and linearity of quantification. Based on this strategy, the method limit of quantification was 0.1 ng/g. The limits of quantification were 8 ng/g for liquid milk and 15 ng/g for dry milk powder. This method provided a reproducible and stable approach to sensitive detection and quantification of melamine. 展开更多
关键词 反相流相色谱 质谱分析法 离子对 多反应监测模式 三聚氰胺
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A Systematical Analysis of Tryptic Peptide Identification with Reverse Phase Liquid Chromatography and Electrospray Ion Trap Mass Spectrometry 被引量:1
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作者 WeiSun ShuzhenWu XiaorongWang DexianZheng YouheGao 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2004年第3期174-183,共10页
In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC... In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC-MS/MS) analysis. Fol- lowing protein digestion with trypsin, the peptide mixture was analyzed by on-line RPLC-MS/MS. Bovine serum albumin (BSA) was used to optimize acetonitrile (ACN) elution gradient for tryptic peptides, and Cytochrome C was used to retest the gradient and the sensitivity of LC-MS/MS. The characteristics of identi?ed peptides were also analyzed. In our experiments, the suitable ACN gradient is 5% to 30% for tryptic peptide elution and the sensitivity of LC-MS/MS is 50 fmol. Analysis of the tryptic peptides demonstrated that longer (more than 10 amino acids) and multi-charge state (+2, +3) peptides are likely to be identi?ed, and the hydropathicity of the peptides might not be related to whether it is more likely to be identi?ed or not. The number of identi?ed peptides for a protein might be used to estimate its loading amount under the same sample background. Moreover, in this study the identi?ed peptides present three types of redundancy, namely iden- ti?cation, charge, and sequence redundancy, which may repress low abundance protein identi?cation. 展开更多
关键词 tryptic peptide identification PROTEOMICS reverse phase liquid chromatography electrospray ion trap mass spectrometry
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Determination of Methanol Increment in Mobile Phase Consisting of Methanol and Water by On-line UV Spectrometry in Reversed Phase Liquid Chromatography 被引量:2
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作者 耿信笃 弗莱德依瑞格涅尔 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2002年第1期68-75,共8页
An on-line UV spectrometric method for the quantitative determination ofmethanol increment of methanol-water in the mobile phase (i.e., of greater concentration than thatof the mobile phase) by frontal analysis (FA) o... An on-line UV spectrometric method for the quantitative determination ofmethanol increment of methanol-water in the mobile phase (i.e., of greater concentration than thatof the mobile phase) by frontal analysis (FA) of insulin in reversed phase liquid chromatography(RPLC) was presented. When the methanol increment concentration ranged from 0.05% to 0.50%,V(CH_3OH)/V(H_2O), a set of elution curves could be obtained at 198 nm by a diode-array detector inthe presence of 47% methanol, V(CH_3OH)/V(H_2O) containing 0.03% hydrochloric acid,V(CH_3OH-H_2O)/V(HCl) in the mobile phase. The plateau height of the elution curves of the methanolincrement was found to be proportional to the methanol increment in the mobile phase. The methanolincrement could be determined on a quantitative basis. When the method was used to investigate theelution curve of insulin by FA in RPLC, a small plateau, being the methanol increment, was detectedbefore the usual insulin plateau of each elution curve. In this case the methanol increment wasfound to vary with insulin concentration in the mobile phase. When that concentration was between0.025 mg/mL and 0.30 mg/mL, the methanol increment could be determined in the range from 0.03% to0.19% with a deviation of ±10%. A nuclear magnetic resonance spectrometer (NMR) was also employedto confirm the obtained result. A methodology with a very rigorous experimental procedure forobtaining results of such accuracy is also included. The presented result may be used to prove thata displacement process definitely occurs as insulin is adsorbed by the RPLC stationary phase inFA. 展开更多
关键词 reversed-phase liquid chromatography retention mechanism methanolincrement INSULIN
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RETENTION PREDICTION OF CONJUGATED BILE ACIDS AND BARBITUR ATES BY USING INTER ACTION INDEX IN REVERSED PHASE LIQUID CHROMATOGRAPHY
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作者 陈农 张玉奎 卢佩章 《Chinese Science Bulletin》 SCIE EI CAS 1992年第3期208-212,共5页
Ⅰ. INTRODUCTION Recently, reversed phase liquid chromatography (RPLC) has become a very efficient standard technique for the modern analyses and is widely used for the analysis of many types of compounds. Retention p... Ⅰ. INTRODUCTION Recently, reversed phase liquid chromatography (RPLC) has become a very efficient standard technique for the modern analyses and is widely used for the analysis of many types of compounds. Retention prediction plays an important part in the thermodynamic studies in RPLC. Many attempts have been made to establish Kováts-like retention 展开更多
关键词 interaction INDEX reversed phase liquid chromatography retention prediction CONJUGATED BILE ACIDS barbiturates.
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A Direct Evidence of Stoichiometric Displacement between Insulin and Methanol in Reversed Phase Liquid Chromatography
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作者 耿信笃 弗莱德 依 瑞格涅尔 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2003年第2期181-188,共8页
With four kinds of mobile phases, methanol water, ethanol water, 2 propanol and acetonitrile water (all containing 0 1% triflu roacetic acid), the displacement between solute and solvent in RPLC was proved to be... With four kinds of mobile phases, methanol water, ethanol water, 2 propanol and acetonitrile water (all containing 0 1% triflu roacetic acid), the displacement between solute and solvent in RPLC was proved to be universal in frontal analysis (FA). Based on the measured Z value in usual RPLC to be a constant and the quantitative determination of methanol increment in mobile phase in FA, the stoichiometric displacement (SD) between insulin and methanol was directly proved by the experiment. The SD was also proved to occur only on about the one fourth of the maximum amount of adsorbed methanol in the bonded phase layer (BPL) without any dynamic problem of mass transfer, while in FA, the SD firstly occurs on the surface of the BPL and then gradually sinks into the deeper sites companied with a dynamic problem. Although the displaced solvent by the same solute is less in the former case, the SD is independent of how deep of the solute enters the BPL. In addition, the adsorbed amount of solute on an adsorbent not only depends on the numbers of the adsorbed layer on the adsorbent surface, but also on the extent of the complete removal of the displaceable solvent in the BPL. The physical fundamental of the SD and the methodology for investigation were also discussed. 展开更多
关键词 liquid solid system reversed phase liquid chromatography retention mechanism stoichiometric displacement adsorption mechanism INSULIN frontal analysis
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Dependence of Elution Curve and Adsorption Isotherms of Insulin on Composition of Mobile Phase of Frontal Analysis in Reversed Phase Liquid Chromatography
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作者 耿信笃 弗莱德依瑞格涅尔 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2003年第4期429-435,共7页
With frontal analysis (FA), the dependence of adsorption isotherms of insulin on the composition of mobile phase in reversed phase liquid chromatography (RPLC) has been investigated. This is also a good example to em... With frontal analysis (FA), the dependence of adsorption isotherms of insulin on the composition of mobile phase in reversed phase liquid chromatography (RPLC) has been investigated. This is also a good example to employ the stoichiometric displacement theory (SDT) for investigating solute adsorption in physical chemistry. Six kinds of mobile phase in RPLC were employed to study the effects on the elution curves and adsorption isotherms of insulin. The key points of this paper are: (1) The stability of insulin due to delay time after preparing, the organic solvent concentration, the kind and the concentration of ion pairing agent in mobile phase were found to affect both elution curve and adsorption isotherm very seriously. (2) To obtain a valid and comparable result, the composition of the mobile phase employed in FA must be as same as possible to that in usual RPLC of either analytical scale or preparative purpose. (3) Langmuir Equation and the SDT were employed to imitate these obtained adsorption isotherms. The expression for solute adsorption from solution of the SDT was found to have a better elucidation to the insulin adsorption from mobile phase in RPLC. 展开更多
关键词 reverse phase liquid chromatography (RPLC) solid liquid system stoichiometric displacement theory (SDT) adsorption mechanism adsorption isotherm frontal analysis (FA) INSULIN
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