This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches...This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches have been carried out on both silica gel matrix and polymer supporters in order to compare the two ordinary kinds of stationary phases,and the phenomenon is similar. Separation is based on differences in the stabilities of analyte-additive complexes in solution.Retention times of analytes can ...展开更多
Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and t...Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions enantiomeric propanolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3 v/v) as mobile phase on Lichrospher-100-DIOL column.展开更多
High-resolution liquid chromatography separation is essential to in-depth proteomic profiling of complex biological samples.Herein,we established an ion-pair reversed-phase×reversed-phase two-dimensional liquid c...High-resolution liquid chromatography separation is essential to in-depth proteomic profiling of complex biological samples.Herein,we established an ion-pair reversed-phase×reversed-phase two-dimensional liquid chromatography(IPRP×RP 2DLC)strategy for comprehensive proteomic analysis.Both RPLC separation dimensions were performed at low pH,with trifluoroacetic acid(TFA)and formic acid(FA)as mobile phase addictive,respectively.As the good separation resolution offered by ion-pairing effect of TFA,the fractionation efficiency was greatly improved with 74.0%peptides identified in just one fraction.Comparing with conventional high pH RP fractionation,the overall separation rate of IPRP was about 1.6 times that of high-pH RP,which increased the number of identified peptides by 21%.Further,2169 proteins and 8540 peptides were confidently identified from crude serum sample by our IPRP×RP 2DLC strategy,exhibiting great potential in clinical proteomics in the future.展开更多
A method for rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography with ultraviolet detection was developed. Chromatographic separations were performed on a...A method for rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography with ultraviolet detection was developed. Chromatographic separations were performed on a reversed-phase silica-based monolithic column using 1-heptanesulfonic acid sodium-acetonitrile as mobile phase. The effects of ion-pair reagent and acetonitrile concentration on retention of the cations were investigated. The retention times of the cations accord with carbon number rule. The method has been successfully applied to the determination of four ionic liquids synthesized by organic chemistry laboratory.展开更多
A method was developed for the determination of tetraethyl ammonium (TEA) by reversed-phase ion- pair chromatography with indirect ultraviolet detection, Chromatographic separation was achieved on a reversed-phase C...A method was developed for the determination of tetraethyl ammonium (TEA) by reversed-phase ion- pair chromatography with indirect ultraviolet detection, Chromatographic separation was achieved on a reversed-phase C18 column using background ultraviolet absorbing reagent - ion-pair reagent - organic solvent as mobile phase. The effects of the background ultraviolet absorbing reagents, detection wavelength, ion-pair reagents, organic solvents and column temperature on the determination method were investigated and the retention rules discussed. Results found that TEA could be successfully analyzed by using 0.7 mmol/L 4-aminophenol hydrochloride and 0.15 mmol/L 1-heptanesulfonic acid sodium mixed with 20% (v/v) methanol as mobile phase at a UV detection wavelength of 230 nm. Under these conditions, the retention time of tetraethyl ammonium was 2.85 min. The detection limit (S/N = 3) for TEA was 0.06 mg/L. The relative standard deviations (n = 5) for peak area and retention time were 0.35% and 0.02%, respectively. The method has been successfully applied to the determination of synthesized tetraethyl ammonium bromide. Recovery of tetraethyl ammonium after spiking was 99.1%.展开更多
Fast analysis of thiocyanate by ion-pair chromatography using a silica-based monolithic column and direct conductivity detection was carried out. Chromatographic separation was performed on a Chromolith Speed ROD RP-1...Fast analysis of thiocyanate by ion-pair chromatography using a silica-based monolithic column and direct conductivity detection was carried out. Chromatographic separation was performed on a Chromolith Speed ROD RP-18e using tetrabutylammonium hydroxide (TBA)-phthalic acid-acetonitrile as eluent. The effects of eluent concentration, eluent pH value, column temperature and flow rate on retention time of thiocyanate were investigated. The optimized chromatographic conditions for the determination of thiocyanate were as follows: 0.25 mmol/L TBA-0.18 mmol/L phthalate-7% acetonitrile (pH 5.5) as eluent, column temperature of 30 ℃, and flow rate of 6.0 mL/min. Retention time of thiocyanate was less than 1 min under the conditions. Common anions (Cl^-, NO3 , SO42 and I^- ) did not interfere with the determination of thiocyanate. Detection limit (S/N = 3) of thiocyanate was 0.96 mg/L. Calibration graph between peak area and the concentration of thiocyanate was linear in the range of 2.0- 100.0 mg/L. Relative standard deviation (RSD) of chromatographic peak area was 1.4% (n = 5). This method has been applied to the determination of thiocyanate in ionic liquids. Recoveries of thiocyanate after spiking were 100.5%.展开更多
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
Ⅰ. INTRODUCTIONReversed-phase ion-pair liquid chromatography is widely used in the separation of ionized organic compounds. In recent years, the separation of inorganic ions by the reversedphase ion-pair liquid chrom...Ⅰ. INTRODUCTIONReversed-phase ion-pair liquid chromatography is widely used in the separation of ionized organic compounds. In recent years, the separation of inorganic ions by the reversedphase ion-pair liquid chromatography with indirect UV detection or conductivity展开更多
An ion-pair reversed-phase high-performance liquid chromatographic method, using tetrabutylammonium bromide (TBAB) as ion-pair reagent, has been developed for the analysis of cyanuric acid (CA) in milk powder and ...An ion-pair reversed-phase high-performance liquid chromatographic method, using tetrabutylammonium bromide (TBAB) as ion-pair reagent, has been developed for the analysis of cyanuric acid (CA) in milk powder and swimming pool water. It was found that the effect of the concentrations of ion-pair reagent on the retention of cyanuric acid was different for standard solution and different real samples. The separation was carried out on a reversed-phase C18 column with 85 : 15 (V/V) water-acetonitrile (ACN) containing different concentration of TBAB as mobile phase for different samples. The linear range of the calibration curve for CA was 0.1-100 mg·L^-1 The detection limits calculated at S/N=3 was 0.11 mg-L^-1 for the analysis of milk powder and 0.31 mg·L^-1 for the analysis of swimming pool water, respectively. The method was successfully applied to the analysis of CA in milk powder and swimming pool water.展开更多
[Objectives]This paper aims to establish a method to simultaneously determine the content ofβ-asarone in Rhizoma Acori Tatarinowii dried by three different methods.[Methods]Reversed-phase high-performance liquid chro...[Objectives]This paper aims to establish a method to simultaneously determine the content ofβ-asarone in Rhizoma Acori Tatarinowii dried by three different methods.[Methods]Reversed-phase high-performance liquid chromatography was used,and the chromatographic conditions were as follows:column,Thermo SCIENTIFIC Hypersil GOLD Dim.(mm);mobile phase,methanol-0.1%phosphoric acid(63∶37);column temperature,30℃;flow rate,1mL/min;detection wavelength,257 nm;sample size,10μL.[Results]The linear range of the injection volume ofβ-asarone was 49.28-246.40μg/mL(R=0.9993);the limit of quantification was 0.85 ng and the detection limit was 0.34 ng;the RSD values of precision,stability and reproducibility tests were all less than 3%;and the sample recovery rate was 98.53%-98.97%(RSD<3.00).The results show that the content ofβ-asarone was highest in shade-dried Rhizoma Acori Tatarinowii.The order ofβ-asarone content was as follows:Rhizoma Acori Tatarinowii dried in shade>Rhizoma Acori Tatarinowii dried at 55℃>Rhizoma Acori Tatarinowii dried at 60℃.[Conclusions]This method is sensitive,reliable,and reproducible.It can be used to simultaneously determine the content ofβ-asarone in Rhizoma Acori Tatarinowii dried by three different methods.展开更多
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
In this paper, a quadruple-potential waveform was investigated and optimized for the determination of gentamicin by reversed phase ion-pair chromatography. Instead of a relatively high positive potential, a negative p...In this paper, a quadruple-potential waveform was investigated and optimized for the determination of gentamicin by reversed phase ion-pair chromatography. Instead of a relatively high positive potential, a negative potential was adopted as a potential for the cleaning of gold working electrode. By this way, the formation of gold oxide resulting from the application of high positive potential during the analyte detection and electrode cleaning was greatly reduced, and therefore, the dissolution and recession of gold working electrode was also reduced. The good condition of gold working electrode achieved by this quadruple-potential waveform can help us to obtain a good reproducibility. In order to acquire signal-to-noise ratio as high as possible, several waveform parameters affecting the detection of gentamicin were carefully selected. The analytical method has been applied to the determination of two real gentamicin samples, and good results with low relative standard deviation not more than 4% were obtained.展开更多
Hydrophilic metabolites play important roles in cellular energy metabolism,signal transduction,immunity.However,there are challenges in both identification and quantification of the hydrophilic metabolites due to thei...Hydrophilic metabolites play important roles in cellular energy metabolism,signal transduction,immunity.However,there are challenges in both identification and quantification of the hydrophilic metabolites due to their weak interactions with C18-reversed-phase liquid chromatography(RPLC),leading to poor retention of hydrophilic metabolites on the columns.Many strategies have been put forward to increase the retention behavior of hydrophilic metabolites in the RPLC system.Non-derivatization methods are mainly focused on the development of new chromatographic techniques with different separation mechanisms,such as capillary electrophoresis,ion-pairing RPLC etc.Derivatization methods improve the hydrophobicity of metabolites and can enhance the MS response.This review mainly focused on the illustration of challenges of LCMS in the analysis of hydrophilic metabolomics field,and summarized the non-derivatization and derivatization strategies,with the intention of providing multiple choices for analysis of hydrophilic metabolites.展开更多
A method of ion-pair chromatography with direct conductivity detection was developed on a silicabased monolithic column for the fast and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cation...A method of ion-pair chromatography with direct conductivity detection was developed on a silicabased monolithic column for the fast and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations. The effects of the mobile phase, column temperature and flow rate on the retention of the cations were investigated. The retention rules were discussed. As an ion-pair reagent, sodium heptanesulfonate is more suitable than sodium pentanesulfonate for the separation and determination of piperidinium and pyrrolidinium cations. The increase of ion-pair reagent concentration led to the increased retention time of the cations. When acetonitrile content and mobile phase flow were increased, the retention time of the cations became shorter. The retention of piperidinium and pyrrolidinium cations is an exothermic process, and the retention of the cations conforms to the carbon number rule. The chromatographic analysis was performed using the Chromolith Speed ROD RP-18 e column, 0.5 mmol/L sodium heptanesulfonate-5% acetonitrile as the mobile phase at a flow rate of3.0 m L/min and column temperature of 30℃. Separation of N-methyl-N-ethyl piperidinium, N-methylN-propyl piperidinium, N-methyl-N-butyl piperidinium and N-methyl-N-ethyl pyrrolidinium, Nmethyl-N-propyl pyrrolidinium, N-methyl-N-butyl pyrrolidinium cations were achieved within10 min. The detection limits(S/N = 3) were between 0.19 and 3.08 mg/L. Relative standard deviations(n = 5) for peak areas were less than 1.2%. The method has been applied to the determination of piperidinium and pyrrolidinium cations in ionic liquid samples. The spiked recoveries of ionic liquid cations were between 96% and 111%. The method is accurate, reliable, rapid, and has a better practicability.展开更多
One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion-exchange chromatography, gel filtration chromatography and reverse-phase hi...One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion-exchange chromatography, gel filtration chromatography and reverse-phase high performance liquid chromatography (HPLC). The final purified fraction was checked on the Smart system HPLC and was judged as a pure fraction. The results of physical and biological analysis revealed that this fraction is heat stable and showed strong activities against Gram-positive bacterial growth. It possesses antibicrobial peptide properties and is worth further investigation.展开更多
基金supported by National Natural Science Foundation of China(No.20775070)Zhejiang Qianjiang Project of Science and Technology for Competent People(No.2008R10028)+1 种基金Zhejiang Provincial Natural Science Foundation of China(Nos.R4080124,Y4080064)Zhejiang Provincial Analysis and Testing Foundation of China(No.2007F70061)
文摘This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches have been carried out on both silica gel matrix and polymer supporters in order to compare the two ordinary kinds of stationary phases,and the phenomenon is similar. Separation is based on differences in the stabilities of analyte-additive complexes in solution.Retention times of analytes can ...
文摘Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions enantiomeric propanolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3 v/v) as mobile phase on Lichrospher-100-DIOL column.
基金National Key R&D Program of China(No.2019YFE0119300)National Natural Science Foundation of China(No.32088101)+1 种基金Original Innovation Project of CAS(No.ZDBS-LY-SLH032)Project of Dalian Institute of Chemical Physics,CAS,China(No.DICPI202007).
文摘High-resolution liquid chromatography separation is essential to in-depth proteomic profiling of complex biological samples.Herein,we established an ion-pair reversed-phase×reversed-phase two-dimensional liquid chromatography(IPRP×RP 2DLC)strategy for comprehensive proteomic analysis.Both RPLC separation dimensions were performed at low pH,with trifluoroacetic acid(TFA)and formic acid(FA)as mobile phase addictive,respectively.As the good separation resolution offered by ion-pairing effect of TFA,the fractionation efficiency was greatly improved with 74.0%peptides identified in just one fraction.Comparing with conventional high pH RP fractionation,the overall separation rate of IPRP was about 1.6 times that of high-pH RP,which increased the number of identified peptides by 21%.Further,2169 proteins and 8540 peptides were confidently identified from crude serum sample by our IPRP×RP 2DLC strategy,exhibiting great potential in clinical proteomics in the future.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.B200909)the Program for Scientific and Technological Innovation Team Construction in Universities of Heilongjiang Province(No. 2011TD010)
文摘A method for rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography with ultraviolet detection was developed. Chromatographic separations were performed on a reversed-phase silica-based monolithic column using 1-heptanesulfonic acid sodium-acetonitrile as mobile phase. The effects of ion-pair reagent and acetonitrile concentration on retention of the cations were investigated. The retention times of the cations accord with carbon number rule. The method has been successfully applied to the determination of four ionic liquids synthesized by organic chemistry laboratory.
基金supported by the Natural Science Foundation of Heilongjiang Province(Grant No.B201307)the Ministry of Education of Heilongjiang Province(No.12531192)the Program for Scientific and Technological Innovation Team Construction in Universities of Heilongjiang Province(No. 2011TD010)
文摘A method was developed for the determination of tetraethyl ammonium (TEA) by reversed-phase ion- pair chromatography with indirect ultraviolet detection, Chromatographic separation was achieved on a reversed-phase C18 column using background ultraviolet absorbing reagent - ion-pair reagent - organic solvent as mobile phase. The effects of the background ultraviolet absorbing reagents, detection wavelength, ion-pair reagents, organic solvents and column temperature on the determination method were investigated and the retention rules discussed. Results found that TEA could be successfully analyzed by using 0.7 mmol/L 4-aminophenol hydrochloride and 0.15 mmol/L 1-heptanesulfonic acid sodium mixed with 20% (v/v) methanol as mobile phase at a UV detection wavelength of 230 nm. Under these conditions, the retention time of tetraethyl ammonium was 2.85 min. The detection limit (S/N = 3) for TEA was 0.06 mg/L. The relative standard deviations (n = 5) for peak area and retention time were 0.35% and 0.02%, respectively. The method has been successfully applied to the determination of synthesized tetraethyl ammonium bromide. Recovery of tetraethyl ammonium after spiking was 99.1%.
基金supported by the Program for Scientifc and Technological Innovation Team Construction in Universities of Heilongjiang Province (No. 2011TD010)
文摘Fast analysis of thiocyanate by ion-pair chromatography using a silica-based monolithic column and direct conductivity detection was carried out. Chromatographic separation was performed on a Chromolith Speed ROD RP-18e using tetrabutylammonium hydroxide (TBA)-phthalic acid-acetonitrile as eluent. The effects of eluent concentration, eluent pH value, column temperature and flow rate on retention time of thiocyanate were investigated. The optimized chromatographic conditions for the determination of thiocyanate were as follows: 0.25 mmol/L TBA-0.18 mmol/L phthalate-7% acetonitrile (pH 5.5) as eluent, column temperature of 30 ℃, and flow rate of 6.0 mL/min. Retention time of thiocyanate was less than 1 min under the conditions. Common anions (Cl^-, NO3 , SO42 and I^- ) did not interfere with the determination of thiocyanate. Detection limit (S/N = 3) of thiocyanate was 0.96 mg/L. Calibration graph between peak area and the concentration of thiocyanate was linear in the range of 2.0- 100.0 mg/L. Relative standard deviation (RSD) of chromatographic peak area was 1.4% (n = 5). This method has been applied to the determination of thiocyanate in ionic liquids. Recoveries of thiocyanate after spiking were 100.5%.
文摘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.
文摘Ⅰ. INTRODUCTIONReversed-phase ion-pair liquid chromatography is widely used in the separation of ionized organic compounds. In recent years, the separation of inorganic ions by the reversedphase ion-pair liquid chromatography with indirect UV detection or conductivity
文摘An ion-pair reversed-phase high-performance liquid chromatographic method, using tetrabutylammonium bromide (TBAB) as ion-pair reagent, has been developed for the analysis of cyanuric acid (CA) in milk powder and swimming pool water. It was found that the effect of the concentrations of ion-pair reagent on the retention of cyanuric acid was different for standard solution and different real samples. The separation was carried out on a reversed-phase C18 column with 85 : 15 (V/V) water-acetonitrile (ACN) containing different concentration of TBAB as mobile phase for different samples. The linear range of the calibration curve for CA was 0.1-100 mg·L^-1 The detection limits calculated at S/N=3 was 0.11 mg-L^-1 for the analysis of milk powder and 0.31 mg·L^-1 for the analysis of swimming pool water, respectively. The method was successfully applied to the analysis of CA in milk powder and swimming pool water.
基金Key Research and Development Project of Department of Science and Technology of Guangxi Zhuang Autonomous Region(AB19110003)Project for Improving Basic Scientific Research Ability of Young and Middle-aged Teachers in Colleges and Universities of Guangxi(2019KY0341,2019ky0344)+2 种基金Open Project of Guangxi Zhuang Yao Medicine Center of Engineering and Technology(KJT1900105)Youth Foundation of Guangxi University of Chinese Medicine(2019QN036,2019QN030)Traditional Chinese Medicine Scientific Research Laboratory(Grade III)of National Administration of Traditional Chinese Medicine:Laboratory of Chinese(Zhuang)Medicine Chemical and Quality Analysis(Guo Zhong Yi Yao Fa 2009[21]).
文摘[Objectives]This paper aims to establish a method to simultaneously determine the content ofβ-asarone in Rhizoma Acori Tatarinowii dried by three different methods.[Methods]Reversed-phase high-performance liquid chromatography was used,and the chromatographic conditions were as follows:column,Thermo SCIENTIFIC Hypersil GOLD Dim.(mm);mobile phase,methanol-0.1%phosphoric acid(63∶37);column temperature,30℃;flow rate,1mL/min;detection wavelength,257 nm;sample size,10μL.[Results]The linear range of the injection volume ofβ-asarone was 49.28-246.40μg/mL(R=0.9993);the limit of quantification was 0.85 ng and the detection limit was 0.34 ng;the RSD values of precision,stability and reproducibility tests were all less than 3%;and the sample recovery rate was 98.53%-98.97%(RSD<3.00).The results show that the content ofβ-asarone was highest in shade-dried Rhizoma Acori Tatarinowii.The order ofβ-asarone content was as follows:Rhizoma Acori Tatarinowii dried in shade>Rhizoma Acori Tatarinowii dried at 55℃>Rhizoma Acori Tatarinowii dried at 60℃.[Conclusions]This method is sensitive,reliable,and reproducible.It can be used to simultaneously determine the content ofβ-asarone in Rhizoma Acori Tatarinowii dried by three different methods.
文摘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.
基金Project supported by the Major State Basic Research Development Program (No. 2003CB415001) of China and the National Natural Science Foundation of China (No. 20475060).
文摘In this paper, a quadruple-potential waveform was investigated and optimized for the determination of gentamicin by reversed phase ion-pair chromatography. Instead of a relatively high positive potential, a negative potential was adopted as a potential for the cleaning of gold working electrode. By this way, the formation of gold oxide resulting from the application of high positive potential during the analyte detection and electrode cleaning was greatly reduced, and therefore, the dissolution and recession of gold working electrode was also reduced. The good condition of gold working electrode achieved by this quadruple-potential waveform can help us to obtain a good reproducibility. In order to acquire signal-to-noise ratio as high as possible, several waveform parameters affecting the detection of gentamicin were carefully selected. The analytical method has been applied to the determination of two real gentamicin samples, and good results with low relative standard deviation not more than 4% were obtained.
基金This work was supported by grant from the National Key R&D Program of China(2017YFC0906800).
文摘Hydrophilic metabolites play important roles in cellular energy metabolism,signal transduction,immunity.However,there are challenges in both identification and quantification of the hydrophilic metabolites due to their weak interactions with C18-reversed-phase liquid chromatography(RPLC),leading to poor retention of hydrophilic metabolites on the columns.Many strategies have been put forward to increase the retention behavior of hydrophilic metabolites in the RPLC system.Non-derivatization methods are mainly focused on the development of new chromatographic techniques with different separation mechanisms,such as capillary electrophoresis,ion-pairing RPLC etc.Derivatization methods improve the hydrophobicity of metabolites and can enhance the MS response.This review mainly focused on the illustration of challenges of LCMS in the analysis of hydrophilic metabolomics field,and summarized the non-derivatization and derivatization strategies,with the intention of providing multiple choices for analysis of hydrophilic metabolites.
基金supported by the Natural Science Foundation of Heilongjiang Province (No. B201307)
文摘A method of ion-pair chromatography with direct conductivity detection was developed on a silicabased monolithic column for the fast and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations. The effects of the mobile phase, column temperature and flow rate on the retention of the cations were investigated. The retention rules were discussed. As an ion-pair reagent, sodium heptanesulfonate is more suitable than sodium pentanesulfonate for the separation and determination of piperidinium and pyrrolidinium cations. The increase of ion-pair reagent concentration led to the increased retention time of the cations. When acetonitrile content and mobile phase flow were increased, the retention time of the cations became shorter. The retention of piperidinium and pyrrolidinium cations is an exothermic process, and the retention of the cations conforms to the carbon number rule. The chromatographic analysis was performed using the Chromolith Speed ROD RP-18 e column, 0.5 mmol/L sodium heptanesulfonate-5% acetonitrile as the mobile phase at a flow rate of3.0 m L/min and column temperature of 30℃. Separation of N-methyl-N-ethyl piperidinium, N-methylN-propyl piperidinium, N-methyl-N-butyl piperidinium and N-methyl-N-ethyl pyrrolidinium, Nmethyl-N-propyl pyrrolidinium, N-methyl-N-butyl pyrrolidinium cations were achieved within10 min. The detection limits(S/N = 3) were between 0.19 and 3.08 mg/L. Relative standard deviations(n = 5) for peak areas were less than 1.2%. The method has been applied to the determination of piperidinium and pyrrolidinium cations in ionic liquid samples. The spiked recoveries of ionic liquid cations were between 96% and 111%. The method is accurate, reliable, rapid, and has a better practicability.
基金Acknowledgments We thank Prof. X.-F. Pang, late Academician of Chinese Academy of Science, for his support in getting this project started. We also thank Prof. Yamakawa (National of Institute of Sericultural and Entomological Science, Japan) for analyzing the purity of the final purified fraction. We thank Dr H. Ma for his suggestions on this project and reading our manuscript. This work was supported partly by the Natural Science Foundation of Guangdong Province (032256), the National Basic Research Program of China under grant 2005CB121000 and the National Natural Science Foundation (30370716).
文摘One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion-exchange chromatography, gel filtration chromatography and reverse-phase high performance liquid chromatography (HPLC). The final purified fraction was checked on the Smart system HPLC and was judged as a pure fraction. The results of physical and biological analysis revealed that this fraction is heat stable and showed strong activities against Gram-positive bacterial growth. It possesses antibicrobial peptide properties and is worth further investigation.