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1.
Se Pu ; 37(5): 558-564, 2019 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-31070341

RESUMO

With the development of life science, nano liquid chromatography systems are being involved in various applications in the field of biochemical analysis. Being one of the key components in the system, the nano flow rate pump directly affected the accuracy and repeatability of the analysis. Based on two high precision direct-driven motors and a ten-port switch valve, a single stroke direct-driven ultrahigh pressure nano pump was developed. The results show that the accuracy of the flow rate and stability were better than 1% and 0.7%, respectively, at 500 nL/min. The maximum operating pressure was more than 100 MPa, and the gradient deviation was lower than 1%. The nano pump was used to construct a nano liquid chromatography-mass spectrometry system. A bovine serum albumin (BSA) digest (1 µg) was analyzed by the system, and a sequence coverage of 45% was achieved. Furthermore, 2809 proteins were identified from a 1.25 µg Hela cell digest. All these results demonstrated that the single stroke direct-driven ultrahigh pressure nano pump could be a useful tool in the biochemical analyses, especially for proteome research.

2.
J Food Sci Technol ; 56(1): 428-435, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30728586

RESUMO

A simple, rapid and low-cost determination method of benzo(a)pyrene in fried and baked foods was proposed by high performance liquid chromatography combined with vesicular coacervative supramolecular solvent (SUPRAS) extraction. The vesicular coacervate was composed of 1-octanol and tetrabutylammonium bromide. 200 mg of dried samples with 600 µL SUPRAS could be mixed to extract benzo(a)pyrene. Neither evaporation nor further clean-up steps for the extracts were needed. The overall sample treatment took approximately 30 min, and several samples could be simultaneously treated using conventional lab equipment. Then, benzo(a)pyrene was analyzed via liquid chromatography-fluorescence detection. Parameters affecting the extraction efficiency were investigated and optimized. The results showed good linearity of benzo(a)pyrene with the coefficients of determination (R 2) of more than 0.9999 in the range of 0.1-50.0 µg/kg. The limit of detection of the method was 0.11 µg/kg. Recoveries for spiked samples in the range of 1-10 µg/kg were between 89.86 and 100.01%, with relative standard deviations from 1.20 to 3.20%. Benzo(a)pyrene was present in food samples (including instant noodles, biscuits, rice crust and fried bread stick) at concentrations in the range of 0.08-0.39 µg/kg according to the proposed method. The proposed pretreatment method significantly reduces the analysis time. Furthermore, the solventless approach is in accordance with the green chemistry development trend and has significant application prospects.

3.
Se Pu ; 36(8): 766-771, 2018 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-30251500

RESUMO

The double qualitative principle is a new composite qualitative method based on retention time and the characteristic peaks of the absorption spectra. Using a self-designed and assembled diode array detector (DAD), a high performance liquid chromatography (HPLC) system was constructed. The illegal additive auramine O in six kinds of herbal slices and the active ingredient schisandrin in Jujube kernel Tianma capsules were separated and qualitative analyzed using the HPLC-DAD system. The results showed that there were similar peaks in the chromatograms of pollen typhae and Jujube kernel Tianma capsules when comparing the target analytes. However, the probabilities of the targets were excluded by comparing the absorption spectra. The application results indicated that, based on the double qualitative principle of retention time/absorption spectrum, the interference of impurities in the samples could be well eliminated and the false positives could be avoided. This provides a reference method for the study of traditional Chinese medicine components.


Assuntos
Cromatografia Líquida de Alta Pressão , Ciclo-Octanos/análise , Medicamentos de Ervas Chinesas/análise , Lignanas/análise , Compostos Policíclicos/análise
4.
Se Pu ; 35(9): 1003-1007, 2017 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-29048859

RESUMO

Supramolecular solvent (SUPRAS) is a nano-structured liquid generated from amphiphiles through a sequential self-assembly process. It is an efficient and excellent solvent for the sample extraction. In this paper, a method to directly extract and rapidly analyze polycyclic aromatic hydrocarbons (PAHs) in water samples by high performance liquid chromatography-fluorescence detection (HPLC-FLD) was developed. The composition and amount of SUPRAS were optimized and practical samples were tested. It indicated that the combination of tetrahydrofuran and 1-octanol was a suitable SUPRAS for the extraction of four PAHs with recoveries between 89.08% and 102.47% and relative standard deviations (RSDs) from 1.38% to 3.92% (n=5). Results showed a good linearity of four PAHs with the correlation coefficients (R2) more than 0.999. The limits of detection (LODs) ranged from 1.26 to 9.23 ng/L. The proposed pretreatment method greatly reduces the analysis time. And the solvent-less approach is in accordance with the development trend of green chemistry and of great application prospects.

5.
Se Pu ; 34(2): 130-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27382716

RESUMO

The optical absorption detector is one of the most commonly used detectors for high performance liquid chromatography (HPLC). As a core part of this kind of detector, the designs of flow cells, where light passes through samples for acquiring samples information, will affect the performance of a detector. In order to enhance the signal to noise ratio of detectors and reduce the bands broadening that come from flow cells, it is necessary to design a flow cell with a longer optical path length and a less cell volume while maintaining the luminous flux. However the limitations of the machining capacity make it difficult to increase the optical path length, reduce the cell volume and keep or increase the luminous flux simultaneously. It is a challenge to optimize the designing and machining of flow cells so as to improve the performance of detectors. This review discusses the development of designing flow cells based on the detection principle in some aspects of increasing the optical path length, reducing the cell volume, taking the advantages of total reflection and so on. At the same time, some of the designs are illustrated in detail. These various ideas and structures are significant references for designing flow cells and developing optical absorption detectors.

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