A novel method for simultaneous determination of kolliphor HS15 and miglyol 812 in microemulsion formulation was developed using ultra-high performance liquid chromatography coupled with a nano quantitation analytical...A novel method for simultaneous determination of kolliphor HS15 and miglyol 812 in microemulsion formulation was developed using ultra-high performance liquid chromatography coupled with a nano quantitation analytical detector （UHPLC-NQAD）. All components in kolliphor HS15 and miglyo1812 were well separated on an Acquity BEH C18 column. Mobile phase A was 0.1% trifluoroacetic acid （TFA） in water and mobile phase B was acetonitrile. A gradient elution sequence was programed initially with 60% organic solvent, slowly increased to 100% within 8 min. The flow rate was 0.7 mL/min. Good linearity （r 〉 0.95） was obtained in the range of 27.6-1381.1 μg/mL for polyoxyl 15 hydroxystearate in kolliphor HS15, 0.8-202.0 μg/mL for caprylic acid triglyceride and 2.7-221.9μg/mL for capric acid triglyceride in miglyol 812. The relative standard deviations （RSD） ranged from 0.6% to 1.7% for intra-day precision and from 0.4% to 2.7% for inter-day precision. The overall recoveries （accuracy） were 99.7%-101.4% for polyoxyl 15 hydroxystearate in kolliphor HS15, 96.7%-99.6% for caprylic acid triglyceride, and 94.1%- 103.3% for capric acid triglyceride in miglyol 812. Quantification limits （QL） were determined as 27.6 μg/ mL for polyoxy115 hydroxystearate in kolliphor HS15, 0.8 μg/mL for caprylic acid triglyceride, and 2.7 μg/ mL for capric acid triglyceride in miglyol 812. No interferences were observed in the retention time ranges of kolliphor HSI5 and miglyol 812. The method was validated in terms of specificity, linearity, precision, accuracy, QL, and robustness. The proposed method has been applied to microemulsion for- mulation analyses with good recoveries （82.2%-103.4%）.展开更多
We demonstrate a novel flat-field,dual-optic imaging EUV—soft X-ray spectrometer and monochromator that attains an unprecedented throughput efficiency exceeding 60%by design,along with a superb spectral resolution of...We demonstrate a novel flat-field,dual-optic imaging EUV—soft X-ray spectrometer and monochromator that attains an unprecedented throughput efficiency exceeding 60%by design,along with a superb spectral resolution ofλ/Δλ>200 accomplished without employing variable line spacing gratings.Exploiting the benefits of the conical diffraction geometry,the optical system is globally optimized in multidimensional parameter space to guarantee optimal imaging performance over a broad spectral range while maintaining circular and elliptical polarization states at the first,second,and third diffraction orders.Moreover,our analysis indicates minimal temporal dispersion,with pulse broadening confined within 80 fs tail-to-tail and an FWHM value of 29 fs,which enables ultrafast spectroscopic and pump-probe studies with femtosecond accuracy.Furthermore,the spectrometer can be effortlessly transformed into a monochromator spanning the EUV—soft X-ray spectral region using a single grating with an aberration-free spatial profile.Such capability allows coherent diffractive imaging applications to be conducted with highly monochromatic light in a broad spectral range and extended to the soft X-ray region with minimal photon loss,thus facilitating state-of-the-art imaging of intricate nano-and bio-systems,with a significantly enhanced spatiotemporal resolution,down to the nanometer–femtosecond level.展开更多
In this paper, a method using solid-phase extraction （SPE） and gas chromatography-mass spectro- metry （GC-MS） was developed to simultaneously analyze five taste and odor compounds in surface water, i.e., 2- methyl...In this paper, a method using solid-phase extraction （SPE） and gas chromatography-mass spectro- metry （GC-MS） was developed to simultaneously analyze five taste and odor compounds in surface water, i.e., 2- methylisoborneol （2-MIB）, 2,4,6-trichloroanisole （TCA）, 2-isopropyl-3-methoxy pyrazine （IPMP）, 2-isobutyl-3- methoxy pyrazine （IBMP）, and trans-l,lO-dimethyl- trans-9-decalol （geosmin, GSM）. The mass spectrometry was operated in selective ion monitoring （SIM） mode. Three kinds of SPE columns and three eluting solvents were compared, the C 18 column was chosen as optimum SPE column, and methanol was chosen as the optimum eluting solvent. It was found that the method showed good linearity in the range of 1-200 ng.L^-1 and gave detection limits of 0.5 1.5 ng.L^-1 for individual compounds. Good recoveries （93.5%-108%） and relative standard deviations （1.58%-7.31%） were also obtained. Additionally, concentrations of these taste and odor compounds in Jinan＇s surface and drinking water were analyzed by applying this method, and the results showed that GSM and 2-MIB were the dominant taste and odor compounds in Jinan＇s raw water.展开更多
Ⅰ. THE DFPD FOR GAS CHROMATOGRAPHY In two earlier papers, the carrier gas was mixed with oxygen or air at first and then the mixed gases were introduced to the lower flame of the detector through a central tube. When...Ⅰ. THE DFPD FOR GAS CHROMATOGRAPHY In two earlier papers, the carrier gas was mixed with oxygen or air at first and then the mixed gases were introduced to the lower flame of the detector through a central tube. When large amount of solvent came through the detector, the O2 would be con-展开更多
To the Editor:Hereditary hemochromatosis(HH)is a lateonset autonomic disease characterized by enhanced intestinal absorption of iron and iron overload,which may lead to liver cirrhosis,cardiomyopathy,diabetes,arthriti...To the Editor:Hereditary hemochromatosis(HH)is a lateonset autonomic disease characterized by enhanced intestinal absorption of iron and iron overload,which may lead to liver cirrhosis,cardiomyopathy,diabetes,arthritis,and skin pigmentation.In 1996,Feder et al[1]cloned the gene responsible for HH(HFE)and reported that 85%of HH patients were homozygous for the C282Y mutation in the HFE gene.This was subsequently termed type 1 HH.Other inherited forms of HH exist that are non HFE-related,an example of which is juvenile hemochromatosis(JH);two genotypes that induce JH have been reported thus far.One JH genotype involves the hemojuvelin gene(HJV),which was cloned from a Greek family with JH by Papanikolaou et al[2]and is known as type 2A HH.The other involves the human antimicrobial peptide(HAMP)gene,which encodes hepcidin and is termed type 2B HH.展开更多
In recent years, gas chromatography has given great impetus to the development of organic microanalysis, and has been increasingly adopted as a method for the determination of common elements and functional groups in ...In recent years, gas chromatography has given great impetus to the development of organic microanalysis, and has been increasingly adopted as a method for the determination of common elements and functional groups in organic compounds. has reported the determination of active hydrogen by a combination of the gas chromatographic technique and the LiAlH4 reaction. A method for the same purpose by the gas chromatography accompanied by the Zerewitnoff method is presented in this note. In the classical Zerewitnoff method, the content of active hydrogen in organic compounds is to be obtained from the展开更多
文摘A novel method for simultaneous determination of kolliphor HS15 and miglyol 812 in microemulsion formulation was developed using ultra-high performance liquid chromatography coupled with a nano quantitation analytical detector （UHPLC-NQAD）. All components in kolliphor HS15 and miglyo1812 were well separated on an Acquity BEH C18 column. Mobile phase A was 0.1% trifluoroacetic acid （TFA） in water and mobile phase B was acetonitrile. A gradient elution sequence was programed initially with 60% organic solvent, slowly increased to 100% within 8 min. The flow rate was 0.7 mL/min. Good linearity （r 〉 0.95） was obtained in the range of 27.6-1381.1 μg/mL for polyoxyl 15 hydroxystearate in kolliphor HS15, 0.8-202.0 μg/mL for caprylic acid triglyceride and 2.7-221.9μg/mL for capric acid triglyceride in miglyol 812. The relative standard deviations （RSD） ranged from 0.6% to 1.7% for intra-day precision and from 0.4% to 2.7% for inter-day precision. The overall recoveries （accuracy） were 99.7%-101.4% for polyoxyl 15 hydroxystearate in kolliphor HS15, 96.7%-99.6% for caprylic acid triglyceride, and 94.1%- 103.3% for capric acid triglyceride in miglyol 812. Quantification limits （QL） were determined as 27.6 μg/ mL for polyoxy115 hydroxystearate in kolliphor HS15, 0.8 μg/mL for caprylic acid triglyceride, and 2.7 μg/ mL for capric acid triglyceride in miglyol 812. No interferences were observed in the retention time ranges of kolliphor HSI5 and miglyol 812. The method was validated in terms of specificity, linearity, precision, accuracy, QL, and robustness. The proposed method has been applied to microemulsion for- mulation analyses with good recoveries （82.2%-103.4%）.
基金funding from the National Key Research and Development Program of China(2021YFB3602600)the Chinese Academy of Sciences(CAS)(GJJSTD20200009)(2018-131-S)+3 种基金the National Natural Science Foundation of China(NSFC)(62121003)(10010108B1339-2451)the Beijing Municipal Science&Technology Commission(Z221100006722008)T.P.gratefully acknowledges funding from the European Research Council(ERC)(grant agreement XSTREAM-716950)the Alfred P.Sloan Foundation(FG-2018-10892)。
文摘We demonstrate a novel flat-field,dual-optic imaging EUV—soft X-ray spectrometer and monochromator that attains an unprecedented throughput efficiency exceeding 60%by design,along with a superb spectral resolution ofλ/Δλ>200 accomplished without employing variable line spacing gratings.Exploiting the benefits of the conical diffraction geometry,the optical system is globally optimized in multidimensional parameter space to guarantee optimal imaging performance over a broad spectral range while maintaining circular and elliptical polarization states at the first,second,and third diffraction orders.Moreover,our analysis indicates minimal temporal dispersion,with pulse broadening confined within 80 fs tail-to-tail and an FWHM value of 29 fs,which enables ultrafast spectroscopic and pump-probe studies with femtosecond accuracy.Furthermore,the spectrometer can be effortlessly transformed into a monochromator spanning the EUV—soft X-ray spectral region using a single grating with an aberration-free spatial profile.Such capability allows coherent diffractive imaging applications to be conducted with highly monochromatic light in a broad spectral range and extended to the soft X-ray region with minimal photon loss,thus facilitating state-of-the-art imaging of intricate nano-and bio-systems,with a significantly enhanced spatiotemporal resolution,down to the nanometer–femtosecond level.
文摘In this paper, a method using solid-phase extraction （SPE） and gas chromatography-mass spectro- metry （GC-MS） was developed to simultaneously analyze five taste and odor compounds in surface water, i.e., 2- methylisoborneol （2-MIB）, 2,4,6-trichloroanisole （TCA）, 2-isopropyl-3-methoxy pyrazine （IPMP）, 2-isobutyl-3- methoxy pyrazine （IBMP）, and trans-l,lO-dimethyl- trans-9-decalol （geosmin, GSM）. The mass spectrometry was operated in selective ion monitoring （SIM） mode. Three kinds of SPE columns and three eluting solvents were compared, the C 18 column was chosen as optimum SPE column, and methanol was chosen as the optimum eluting solvent. It was found that the method showed good linearity in the range of 1-200 ng.L^-1 and gave detection limits of 0.5 1.5 ng.L^-1 for individual compounds. Good recoveries （93.5%-108%） and relative standard deviations （1.58%-7.31%） were also obtained. Additionally, concentrations of these taste and odor compounds in Jinan＇s surface and drinking water were analyzed by applying this method, and the results showed that GSM and 2-MIB were the dominant taste and odor compounds in Jinan＇s raw water.
文摘Ⅰ. THE DFPD FOR GAS CHROMATOGRAPHY In two earlier papers, the carrier gas was mixed with oxygen or air at first and then the mixed gases were introduced to the lower flame of the detector through a central tube. When large amount of solvent came through the detector, the O2 would be con-
基金This study was supported by a grant from the Beijing Hospitals Authority Youth Programme(No.QML20181805).
文摘To the Editor:Hereditary hemochromatosis(HH)is a lateonset autonomic disease characterized by enhanced intestinal absorption of iron and iron overload,which may lead to liver cirrhosis,cardiomyopathy,diabetes,arthritis,and skin pigmentation.In 1996,Feder et al[1]cloned the gene responsible for HH(HFE)and reported that 85%of HH patients were homozygous for the C282Y mutation in the HFE gene.This was subsequently termed type 1 HH.Other inherited forms of HH exist that are non HFE-related,an example of which is juvenile hemochromatosis(JH);two genotypes that induce JH have been reported thus far.One JH genotype involves the hemojuvelin gene(HJV),which was cloned from a Greek family with JH by Papanikolaou et al[2]and is known as type 2A HH.The other involves the human antimicrobial peptide(HAMP)gene,which encodes hepcidin and is termed type 2B HH.
文摘In recent years, gas chromatography has given great impetus to the development of organic microanalysis, and has been increasingly adopted as a method for the determination of common elements and functional groups in organic compounds. has reported the determination of active hydrogen by a combination of the gas chromatographic technique and the LiAlH4 reaction. A method for the same purpose by the gas chromatography accompanied by the Zerewitnoff method is presented in this note. In the classical Zerewitnoff method, the content of active hydrogen in organic compounds is to be obtained from the
