[Method] This study aimed to determine trace amount of polycyclic aromatic hydrocarbons(PAHs) in urban sewage by using solid-phase extraction(SPE) coupled with high performance liquid chromatograph(HPLC).[Method] From...[Method] This study aimed to determine trace amount of polycyclic aromatic hydrocarbons(PAHs) in urban sewage by using solid-phase extraction(SPE) coupled with high performance liquid chromatograph(HPLC).[Method] From the aspects of solid-phase extraction column,elution solvent,elution volume,elution speed and so forth,the test conditions of SPE-HPLC method were optimized,and trace amount of PAHs in urban sewage was determined.[Result] The optimized solid-phase extraction conditions were SUPELCLEAN LC-18 solid-phase extraction column,methylene dichloride as elution solvent,15 ml elution volume,2 ml/min elution speed,5 ml/min loading speed,1 000 ml water with 200 ml methanol loading volume.Under the optimized extraction conditions,the recovery was high,namely 76.3%-105.2%;relative standard deviation was 3.8%-6.0%,showing good precision;detection limit was low,only 0.000 8-0.048 0 μg/L.[Conclusion] This method is user-friendly,with high sensitivity and good precision,and suitable for continuous determination of a large volume of water samples.展开更多
The aim of this work is optimizing the techniques to prepare pure cellulose microspheres, which are used as packing adsorbents for high-performance liquid chromatography. Thereupon, cellulose was dissolved in a pre-co...The aim of this work is optimizing the techniques to prepare pure cellulose microspheres, which are used as packing adsorbents for high-performance liquid chromatography. Thereupon, cellulose was dissolved in a pre-cooled NaOH/urea solution, from which various-size microspheres were prepared. The volume-average diameters were controlled approximately at 30 p,m, 8 ~tm and 4 pm grades when cyclohexane, liquid paraffin and pump oil were used as dispersants, respectively. The present investigations reveal that higher viscosity dispersant is suitable for the preparation of smaller-size microspheres, while larger size microspheres are prepared preferably using lower-viscosity dispersant. The chiral stationary phase derived from 8 μm grade microspheres can separate the enantiomers of efavirenz.展开更多
A high-performance liquid chromatographic method for the simultaneous determination of KR-008 and its metabolite in biological fluids was developed The samples were injected directly without further treatment,the comp...A high-performance liquid chromatographic method for the simultaneous determination of KR-008 and its metabolite in biological fluids was developed The samples were injected directly without further treatment,the compounds were separated and analysed on a reversed- phase column under isocratic conditions,including ion pairing.Concentrations in urine and bile were determined by an external standard method.The detection limit was 0.8μg/ml in urine.Preliminary data showed that,following i.p.administration(120mg/kg)of KR-008 to rats,approximately 2.8% of the dose was excreted in urine as unchanged compound and more than 8.9% was as a metabolite;in bile it was 0.73% excreted as unchanged form and above 0.29% as the metabolite.The peak biliary concentration of KR-008 was 0.39mg/ml at 20min after dosing.展开更多
A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and t...A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.展开更多
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
Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatograph...Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatography (HPLC) with a wavelength of UV (ultraviolet) 214 urn and a mobile phase of 18 mmol L-1 KH2PO4 buffer solution (pH 2.1). The thermal stability of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments. The relationships between column temperature, flow rate or solvent pH and retention time were analyzed. At low solvent pH, separation efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time of organic acids. High column temperature was unfavorable for the separation of organic acids. The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time. High thermal stability of organic acids with low concentrations was observed at temperature of 40 ℃-45℃. Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH.展开更多
Amantadine (AMA) is an anti-viral drug used in apiculture to protect honeybee against the sacbrood virus (Morator aetatulae). This study described a reliable high-performance liquid chromatographic (HPLC) method...Amantadine (AMA) is an anti-viral drug used in apiculture to protect honeybee against the sacbrood virus (Morator aetatulae). This study described a reliable high-performance liquid chromatographic (HPLC) method for analyzing AMA in honey using a solid-phase extraction (SPE) cartridge (Plexa PCX) for purification, 4-fluoro-7- nitro-2,1,3-benzoxadiazole (NBD-F) as a pre-column derivatization agent, and fluorometric detection (λex =470 nm, λem=530 nm). The chromatographic separation was performed on an XDB C18 column (150×4.6 mm i.d.) using 0.1% trifluoroacetic acid/acetonitrile (35 ; 65, V/V) as the mobile phase at a flow rate of 1.0 mLomin 1 with a run time of 20 min. Under these optimal conditions, a linear relationship was observed in the range of 0.025--1.0μg·mL-1 with a good correlation coefficient (0.998) and low limit of detection (0.0080 μg·g-1), the recoveries were all above 90%, and the intra-day and inter-day precision (RSD) ranged from 3.4%--5.1%.展开更多
A simple size-exclusion high-performance liquid chromatographic method was developed for rapid molecular mass screening to determine the average molecular mass, polydispersity, and quantity of Taizishen polysaccharide...A simple size-exclusion high-performance liquid chromatographic method was developed for rapid molecular mass screening to determine the average molecular mass, polydispersity, and quantity of Taizishen polysaccharides extract. The screening used a TOSOH TSK-GEL G3000SW high-performance liquid chromatographic column with 0.1 mol/L NaNO3 buffer as the mobile phase and refractive index detector. The molecular mass calibration curve was linear for polysaccharide standards from 10 to 100 kDa with a correlation coefficient of 0.9991. The method can be used to analyze the quantity, average molecular mass, and polydispersity of polysaccharides. In addition, the screening method is suitable for quality control of polysaccharide preparations in Chinese medicines and pharmaceutical products.展开更多
Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chro...Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chromatography-tandem mass spectrometric method for the simultaneous determination of 12 phenolic components has been developed.Six caffeoylquinic acids,two caffeoylshikimic acids,and four flavanonol glucosides were selected for the comprehensive analysis of distribution in different parts(root,stem,and leaf).Results:Twelve phenolic components were linear in the concentration range of 0.005–5.0μg/mL(R^(2)>0.995).The relative standard deviation of intra-day and inter-day precision across three validation runs over the entire concentration range was<5%.The recovery determined was within 5%in terms of relative error.Our results showed that the 12 phenolic compounds were mainly distributed in leaves and stems far more than those in roots.Conclusions:This study provided an ultra-high-performance liquid chromatograph with triple-quadrupole mass spectrometer quantitative method of 12 phenolic components for the QC of cultivated S.glabra.It was found that the phenolic components were significantly accumulated in the aerial parts(stems and leaves)of cultivated S.glabra.展开更多
The study of community composition of algae is essential for understanding the structure and dynamics of the aquatic ecosystem and for evaluating the eutrophic level of the water body.A high-performance liquid chromat...The study of community composition of algae is essential for understanding the structure and dynamics of the aquatic ecosystem and for evaluating the eutrophic level of the water body.A high-performance liquid chromatographic(HPLC)method based on a reversephase C_(18) nonpolar column was developed for the main algal taxa,which includes cyanophytes,bacillariophytes,euglenophytes,dinophytes,and chlorophytes.Based on the elution order using HPLC,19 pigments were identified,and they were chlorophyllide a,19′-butanoyloxyfucoxanthin,chlorophyll c_(1)+c_(2),phephorbides a,peridinin,methyl-chlorophyllide a,fucoxanthin,neoxanthin,violaxanthin,myxoxanthophyll,diadinoxanthin,diatoxanthin,lutein,zeaxanthin,chlorophyll b allomer,chlorophyll b,chlorophyll a allomer,chlorophyll a,andβ,β-carotene.A comparison study of cell microscopic counts and accessory pigment analysis indicated that HPLC analysis could be a useful tool for monitoring phytoplankton communities and their abundance.展开更多
A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of...A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of gradient elution curves.The experimental results verified the theoretical analyses of the applied method.This self-designed control system can achieve approving accuracy,repeatability and low cost,which has a bright outlook for domestic applications.展开更多
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
基金Supported by National Science and Technology Key Project of Water Pollution Control and Management (2012ZX07209-003)
文摘[Method] This study aimed to determine trace amount of polycyclic aromatic hydrocarbons(PAHs) in urban sewage by using solid-phase extraction(SPE) coupled with high performance liquid chromatograph(HPLC).[Method] From the aspects of solid-phase extraction column,elution solvent,elution volume,elution speed and so forth,the test conditions of SPE-HPLC method were optimized,and trace amount of PAHs in urban sewage was determined.[Result] The optimized solid-phase extraction conditions were SUPELCLEAN LC-18 solid-phase extraction column,methylene dichloride as elution solvent,15 ml elution volume,2 ml/min elution speed,5 ml/min loading speed,1 000 ml water with 200 ml methanol loading volume.Under the optimized extraction conditions,the recovery was high,namely 76.3%-105.2%;relative standard deviation was 3.8%-6.0%,showing good precision;detection limit was low,only 0.000 8-0.048 0 μg/L.[Conclusion] This method is user-friendly,with high sensitivity and good precision,and suitable for continuous determination of a large volume of water samples.
基金Funded by National Natural Science Foundation of China(Nos.50973086 and 51273073)Hubei Provincial Department of Education of China(No.Z20081501)
文摘The aim of this work is optimizing the techniques to prepare pure cellulose microspheres, which are used as packing adsorbents for high-performance liquid chromatography. Thereupon, cellulose was dissolved in a pre-cooled NaOH/urea solution, from which various-size microspheres were prepared. The volume-average diameters were controlled approximately at 30 p,m, 8 ~tm and 4 pm grades when cyclohexane, liquid paraffin and pump oil were used as dispersants, respectively. The present investigations reveal that higher viscosity dispersant is suitable for the preparation of smaller-size microspheres, while larger size microspheres are prepared preferably using lower-viscosity dispersant. The chiral stationary phase derived from 8 μm grade microspheres can separate the enantiomers of efavirenz.
文摘A high-performance liquid chromatographic method for the simultaneous determination of KR-008 and its metabolite in biological fluids was developed The samples were injected directly without further treatment,the compounds were separated and analysed on a reversed- phase column under isocratic conditions,including ion pairing.Concentrations in urine and bile were determined by an external standard method.The detection limit was 0.8μg/ml in urine.Preliminary data showed that,following i.p.administration(120mg/kg)of KR-008 to rats,approximately 2.8% of the dose was excreted in urine as unchanged compound and more than 8.9% was as a metabolite;in bile it was 0.73% excreted as unchanged form and above 0.29% as the metabolite.The peak biliary concentration of KR-008 was 0.39mg/ml at 20min after dosing.
文摘A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.
文摘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.
文摘Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatography (HPLC) with a wavelength of UV (ultraviolet) 214 urn and a mobile phase of 18 mmol L-1 KH2PO4 buffer solution (pH 2.1). The thermal stability of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments. The relationships between column temperature, flow rate or solvent pH and retention time were analyzed. At low solvent pH, separation efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time of organic acids. High column temperature was unfavorable for the separation of organic acids. The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time. High thermal stability of organic acids with low concentrations was observed at temperature of 40 ℃-45℃. Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH.
文摘Amantadine (AMA) is an anti-viral drug used in apiculture to protect honeybee against the sacbrood virus (Morator aetatulae). This study described a reliable high-performance liquid chromatographic (HPLC) method for analyzing AMA in honey using a solid-phase extraction (SPE) cartridge (Plexa PCX) for purification, 4-fluoro-7- nitro-2,1,3-benzoxadiazole (NBD-F) as a pre-column derivatization agent, and fluorometric detection (λex =470 nm, λem=530 nm). The chromatographic separation was performed on an XDB C18 column (150×4.6 mm i.d.) using 0.1% trifluoroacetic acid/acetonitrile (35 ; 65, V/V) as the mobile phase at a flow rate of 1.0 mLomin 1 with a run time of 20 min. Under these optimal conditions, a linear relationship was observed in the range of 0.025--1.0μg·mL-1 with a good correlation coefficient (0.998) and low limit of detection (0.0080 μg·g-1), the recoveries were all above 90%, and the intra-day and inter-day precision (RSD) ranged from 3.4%--5.1%.
文摘A simple size-exclusion high-performance liquid chromatographic method was developed for rapid molecular mass screening to determine the average molecular mass, polydispersity, and quantity of Taizishen polysaccharides extract. The screening used a TOSOH TSK-GEL G3000SW high-performance liquid chromatographic column with 0.1 mol/L NaNO3 buffer as the mobile phase and refractive index detector. The molecular mass calibration curve was linear for polysaccharide standards from 10 to 100 kDa with a correlation coefficient of 0.9991. The method can be used to analyze the quantity, average molecular mass, and polydispersity of polysaccharides. In addition, the screening method is suitable for quality control of polysaccharide preparations in Chinese medicines and pharmaceutical products.
基金funded by the Science and Technology Development Fund,Macao SAR(File no.0023/2019/AKP)Guangxi Science and Technology Department Fund(File no.AD17195002)。
文摘Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chromatography-tandem mass spectrometric method for the simultaneous determination of 12 phenolic components has been developed.Six caffeoylquinic acids,two caffeoylshikimic acids,and four flavanonol glucosides were selected for the comprehensive analysis of distribution in different parts(root,stem,and leaf).Results:Twelve phenolic components were linear in the concentration range of 0.005–5.0μg/mL(R^(2)>0.995).The relative standard deviation of intra-day and inter-day precision across three validation runs over the entire concentration range was<5%.The recovery determined was within 5%in terms of relative error.Our results showed that the 12 phenolic compounds were mainly distributed in leaves and stems far more than those in roots.Conclusions:This study provided an ultra-high-performance liquid chromatograph with triple-quadrupole mass spectrometer quantitative method of 12 phenolic components for the QC of cultivated S.glabra.It was found that the phenolic components were significantly accumulated in the aerial parts(stems and leaves)of cultivated S.glabra.
基金This work was supported by grants from the National Key Science Research Project of Eleven Five-Year Plan(Nos.2009ZX07106-003 and 2008ZX07316-004)Tianjin Project of CAS(No.TJZX2-YW-07)+1 种基金Jiangsu Province project(No.BE2008651)Agricultural Science and Technology Achievement Transformation Project(No.2009GB2A100015).
文摘The study of community composition of algae is essential for understanding the structure and dynamics of the aquatic ecosystem and for evaluating the eutrophic level of the water body.A high-performance liquid chromatographic(HPLC)method based on a reversephase C_(18) nonpolar column was developed for the main algal taxa,which includes cyanophytes,bacillariophytes,euglenophytes,dinophytes,and chlorophytes.Based on the elution order using HPLC,19 pigments were identified,and they were chlorophyllide a,19′-butanoyloxyfucoxanthin,chlorophyll c_(1)+c_(2),phephorbides a,peridinin,methyl-chlorophyllide a,fucoxanthin,neoxanthin,violaxanthin,myxoxanthophyll,diadinoxanthin,diatoxanthin,lutein,zeaxanthin,chlorophyll b allomer,chlorophyll b,chlorophyll a allomer,chlorophyll a,andβ,β-carotene.A comparison study of cell microscopic counts and accessory pigment analysis indicated that HPLC analysis could be a useful tool for monitoring phytoplankton communities and their abundance.
基金the National High Technology Research and Development Program (863) of China(No. 2009AA04Z326)the National Natural Science Foundation of China (Nos. 60671059, 60871091 and60588101)+1 种基金the National Basic Research Program (973) of China (Nos. 2005CB724302 and 2005CB724303)the 111 Project from the Ministry of Education of China(No. B08020)
文摘A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of gradient elution curves.The experimental results verified the theoretical analyses of the applied method.This self-designed control system can achieve approving accuracy,repeatability and low cost,which has a bright outlook for domestic applications.
文摘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.