Seven polycyclic aromatic hydrocarbons （PAHs） in atmospheric particulates were determinated by high performance liquid chromatography （HPLC） with fluorescence detector using direction injection and an on-line enri...Seven polycyclic aromatic hydrocarbons （PAHs） in atmospheric particulates were determinated by high performance liquid chromatography （HPLC） with fluorescence detector using direction injection and an on-line enrichment trap column. The method simplified the sample pretreatment, saved time and increased the efficiency. With the on-line trap column, PAHs were separated availably even underground injecting 1.0 ml sample with relatively high column efficiency. The recoveries of the seven PAHs were from 85% to 120% for spiked atmospheric particulate sample. The limit of detection was 15.3-39.6 ng/L （S/N=3.3）. There were good linear correlations between the peak areas and concentrations of the seven kinds of PAHs in the range of 1-50 ng/ml with the correlation coefficients over 0.9970. Furthermore, it also indicated that the method is available to determine PAHs in atmospheric particulates well.展开更多
In the present work, the different sample collection, pretreatment and analytical methods for polycyclic aromatic hydrocarbons （PAHs） in airborne particulates is systematacially reviewed, and the applications of the...In the present work, the different sample collection, pretreatment and analytical methods for polycyclic aromatic hydrocarbons （PAHs） in airborne particulates is systematacially reviewed, and the applications of these pretreatment and analytical methods for PAHs are compared in detail. Some comments on the future expectation are also presented.展开更多
A wavelength dispersive X-ray fluorescence （WD-XRF） spectrometry combined with calibration curve method was estab- lished for simultaneously analyzing low-Z elements （C, N, O） and A1, Si, Fe in polyamide. To inves...A wavelength dispersive X-ray fluorescence （WD-XRF） spectrometry combined with calibration curve method was estab- lished for simultaneously analyzing low-Z elements （C, N, O） and A1, Si, Fe in polyamide. To investigate the origin of plastic material causing deposition and blocking in instrument engines and pipelines, polyamide 6 （PA 6, an engineering plastic） was chosen as the study object on account of its common use in industry. The sample preparation with pressed powder disk has been developed for determination of six elements in PA 6. Pure Cu metal was used as the matrix and PA 6 was regarded as standard sample for C, N, O elements. PA 6 particles were firstly smashed to uniform powder in liquid nitrogen, and then mixed with inorganic standard powders （Fe203, A1203, SIO2, and Na2SiO3）. The mixture was ground to obtain homogeneous calibration materials for WD-XRF analysis. The quantitative property of the calibration curve method for each element was re- liable. The limits of detection （S/N≤3） of C, N, O, A1, Si and Fe using WD-XRF were 249, 120, 101, 6.2, 3.3, and 1.8 μg/g, respectively. To confirm the accuracy of the proposed WD-XRF calibration curve method, inductively coupled plasma optical emission spectroscopy （ICP-OES） detection for A1, Si, Fe and elemental analyzer （EA） analysis for C, N, O were utilized. A good correlation of the WD-XRF results with the measurements of ICP-OES and EA was observed.展开更多
A highly sensitive and specific microplate chemiluminescence enzyme immunoassay (CLEIA) was developed for the quantitative evaluation of carbohydrate antigen 72-4 (CA72-4) in human serum, using luminol-H2O2 catalyzed ...A highly sensitive and specific microplate chemiluminescence enzyme immunoassay (CLEIA) was developed for the quantitative evaluation of carbohydrate antigen 72-4 (CA72-4) in human serum, using luminol-H2O2 catalyzed by horseradish peroxidase (HRP) as the chemiluminescence system. The simple and quick determination was accomplished through a sandwich reaction mode. Several physico-chemical parameters of the immunoreaction, including incubation conditions, antibody coating conditions, dilution ratio of anti-CA72-4-HRP conjugate, and chemiluminescence reaction time, were studied and optimized. The proposed method exhibited a linear range of 0―200 U/mL with correlation coefficient and detection limit of 0.9995 and 0.18 U/mL, respectively. The inter-assay and intra-assay coeffi-cients of variation (CV) were both less than 10%. The average recovery of two clinical sera with low and high concentration CA72-4 was 99.3% and 98.7%, respectively. Normal tumor markers, including AFP, CEA, CA24-2, CA19-9 and CA15-3, did not cross-react with each other. The method's stability was evaluated by assessing its analytical performance after storing the immunoreagents at 4℃ and 37℃ for 7 days. Little difference was found, indicating satisfactory stability of the method. The present method has been successfully applied to the detection of CA72-4 human serum, and showed a good correlation with the commercially available ELISA kit (r 2=0.9383). This method showed great potential in the fabrication of diagnostic kit for CA72-4, and could be well used in diagnosis of cancer in clinical practice.展开更多
Molecularly imprinted polymers(MIPs)for solid-phase extraction and pre-concentration of esculetin have been successfully prepared by the bulk polymerization method using esculetin as a template molecule.Polymers of va...Molecularly imprinted polymers(MIPs)for solid-phase extraction and pre-concentration of esculetin have been successfully prepared by the bulk polymerization method using esculetin as a template molecule.Polymers of varying composition were prepared using different monomers(4-vinylpyridine,methacrylic acid,and acrylamide),ethylene glycol dimethacrylate as the cross-linker,2,2-azobis(2-methylpropinitrile)as the initiator,and different porogen solvents(ethanol,acetone/methanol,and acetonitrile).The best polymer was obtained when 4-vinylpyridine was used as the monomer and acetone/methanol(3:2)as the porogen solvent,whereas the template:-monomer:-cross-linker ratio was 1:4:20.The imprinting factor of the selected MIPs for esculetin was 3.77.The polymers were evaluated according to their selective recognition properties for esculetin and structurally-related compounds(esculin,scopoletin,coumarin,and 7-methoxycoumarin).Chemical and morphological characterizations of the polymers were investigated by FTIR and scanning electron microscope,which confirmed a high degree of polymerization.Surface area,pore volume,and pore size of the polymer were investigated by Brunauer-Emmett-Teller analysis.MIPs were also successfully used as solid-phase adsorbent materials for the extraction of esculetin from tobacco leaves.Esculetin contents in dried tobacco leaves were found to be(9.27±0.17)μg g-1.展开更多
A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmet...A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmetic products. A canular extractor was assembled by mounting a hollow fiber inside an external tube with a tee-connector. The organic solvent was immobilized into the fiber to form a liquid membrane as the acceptor phase. The sample was continuously injected into the extractor and the UV filters were extracted from the aqueous sample into organic acceptor phase. The main parameters affecting HF-LPME including extraction solvent, sample volume, sample flow rate, pH values and ionic strength were investigated. Toluene has been verified to be suitable as the acceptor phase. Under the optimized HF-LPME conditions, the enrichment factors of five UV filters varying from 24 to 57 were achieved. The limits of detection for the five UV filters were in the range of 1-100 μg L-1 .The relative standard deviations (RSDs) of HF-LPME and HPLC analysis were lower than 5.2%. The proposed method has been successfully applied to the analysis of the varied cosmetic products.展开更多
基金Project supported by the National Natural Science Foundation of China (No.20437020)Major Research Program of Chinese Academy of Sciences (No.KZCX3-SW-432).
文摘Seven polycyclic aromatic hydrocarbons （PAHs） in atmospheric particulates were determinated by high performance liquid chromatography （HPLC） with fluorescence detector using direction injection and an on-line enrichment trap column. The method simplified the sample pretreatment, saved time and increased the efficiency. With the on-line trap column, PAHs were separated availably even underground injecting 1.0 ml sample with relatively high column efficiency. The recoveries of the seven PAHs were from 85% to 120% for spiked atmospheric particulate sample. The limit of detection was 15.3-39.6 ng/L （S/N=3.3）. There were good linear correlations between the peak areas and concentrations of the seven kinds of PAHs in the range of 1-50 ng/ml with the correlation coefficients over 0.9970. Furthermore, it also indicated that the method is available to determine PAHs in atmospheric particulates well.
基金Project supported by the National Natural Science Foundation of China (No. 20437020 20575073) NSFC-JSPS Joint Research Project (No. 20511140134) the Major Research Program of Chinese Academy of Sciences (KZCX3-SW-432)
文摘In the present work, the different sample collection, pretreatment and analytical methods for polycyclic aromatic hydrocarbons （PAHs） in airborne particulates is systematacially reviewed, and the applications of these pretreatment and analytical methods for PAHs are compared in detail. Some comments on the future expectation are also presented.
基金supported by the Research Fund for the Doctoral Program of Higher Education (20110002110052)
文摘A wavelength dispersive X-ray fluorescence （WD-XRF） spectrometry combined with calibration curve method was estab- lished for simultaneously analyzing low-Z elements （C, N, O） and A1, Si, Fe in polyamide. To investigate the origin of plastic material causing deposition and blocking in instrument engines and pipelines, polyamide 6 （PA 6, an engineering plastic） was chosen as the study object on account of its common use in industry. The sample preparation with pressed powder disk has been developed for determination of six elements in PA 6. Pure Cu metal was used as the matrix and PA 6 was regarded as standard sample for C, N, O elements. PA 6 particles were firstly smashed to uniform powder in liquid nitrogen, and then mixed with inorganic standard powders （Fe203, A1203, SIO2, and Na2SiO3）. The mixture was ground to obtain homogeneous calibration materials for WD-XRF analysis. The quantitative property of the calibration curve method for each element was re- liable. The limits of detection （S/N≤3） of C, N, O, A1, Si and Fe using WD-XRF were 249, 120, 101, 6.2, 3.3, and 1.8 μg/g, respectively. To confirm the accuracy of the proposed WD-XRF calibration curve method, inductively coupled plasma optical emission spectroscopy （ICP-OES） detection for A1, Si, Fe and elemental analyzer （EA） analysis for C, N, O were utilized. A good correlation of the WD-XRF results with the measurements of ICP-OES and EA was observed.
基金Supported by the National Basic Research Program of China (Grant No. 2007CB714507)the National High Technology Research and Development Program of China (Grant No. 2006AA02Z4A8)
文摘A highly sensitive and specific microplate chemiluminescence enzyme immunoassay (CLEIA) was developed for the quantitative evaluation of carbohydrate antigen 72-4 (CA72-4) in human serum, using luminol-H2O2 catalyzed by horseradish peroxidase (HRP) as the chemiluminescence system. The simple and quick determination was accomplished through a sandwich reaction mode. Several physico-chemical parameters of the immunoreaction, including incubation conditions, antibody coating conditions, dilution ratio of anti-CA72-4-HRP conjugate, and chemiluminescence reaction time, were studied and optimized. The proposed method exhibited a linear range of 0―200 U/mL with correlation coefficient and detection limit of 0.9995 and 0.18 U/mL, respectively. The inter-assay and intra-assay coeffi-cients of variation (CV) were both less than 10%. The average recovery of two clinical sera with low and high concentration CA72-4 was 99.3% and 98.7%, respectively. Normal tumor markers, including AFP, CEA, CA24-2, CA19-9 and CA15-3, did not cross-react with each other. The method's stability was evaluated by assessing its analytical performance after storing the immunoreagents at 4℃ and 37℃ for 7 days. Little difference was found, indicating satisfactory stability of the method. The present method has been successfully applied to the detection of CA72-4 human serum, and showed a good correlation with the commercially available ELISA kit (r 2=0.9383). This method showed great potential in the fabrication of diagnostic kit for CA72-4, and could be well used in diagnosis of cancer in clinical practice.
基金supported by the Yunnan Green Tobacco Production Research(2011YN01)the China Equipment and Education Resources System(CERS-1-75)
文摘Molecularly imprinted polymers(MIPs)for solid-phase extraction and pre-concentration of esculetin have been successfully prepared by the bulk polymerization method using esculetin as a template molecule.Polymers of varying composition were prepared using different monomers(4-vinylpyridine,methacrylic acid,and acrylamide),ethylene glycol dimethacrylate as the cross-linker,2,2-azobis(2-methylpropinitrile)as the initiator,and different porogen solvents(ethanol,acetone/methanol,and acetonitrile).The best polymer was obtained when 4-vinylpyridine was used as the monomer and acetone/methanol(3:2)as the porogen solvent,whereas the template:-monomer:-cross-linker ratio was 1:4:20.The imprinting factor of the selected MIPs for esculetin was 3.77.The polymers were evaluated according to their selective recognition properties for esculetin and structurally-related compounds(esculin,scopoletin,coumarin,and 7-methoxycoumarin).Chemical and morphological characterizations of the polymers were investigated by FTIR and scanning electron microscope,which confirmed a high degree of polymerization.Surface area,pore volume,and pore size of the polymer were investigated by Brunauer-Emmett-Teller analysis.MIPs were also successfully used as solid-phase adsorbent materials for the extraction of esculetin from tobacco leaves.Esculetin contents in dried tobacco leaves were found to be(9.27±0.17)μg g-1.
基金supported by the National Natural Science Foundation of China (90813015 & 20935002)
文摘A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmetic products. A canular extractor was assembled by mounting a hollow fiber inside an external tube with a tee-connector. The organic solvent was immobilized into the fiber to form a liquid membrane as the acceptor phase. The sample was continuously injected into the extractor and the UV filters were extracted from the aqueous sample into organic acceptor phase. The main parameters affecting HF-LPME including extraction solvent, sample volume, sample flow rate, pH values and ionic strength were investigated. Toluene has been verified to be suitable as the acceptor phase. Under the optimized HF-LPME conditions, the enrichment factors of five UV filters varying from 24 to 57 were achieved. The limits of detection for the five UV filters were in the range of 1-100 μg L-1 .The relative standard deviations (RSDs) of HF-LPME and HPLC analysis were lower than 5.2%. The proposed method has been successfully applied to the analysis of the varied cosmetic products.
