Royal Society Open Science
·
2021
·Vol. 8
·期 8
·
IF 2.963
Xiangdong Qing,Xiaohong Zhou,Ling Xu,Jin Zhang,Yi Huang,Li Lin,Zhi Liu,Xiaohua Zhang
For the first time, alternating trilinear decomposition-assisted multivariate curve resolution (ATLD-MCR) was applied to analyse complex gas chromatography–mass spectrometric (GC-MS) data with severe baseline drifts, serious co-elution peaks and slight retention time shifts for the simultaneous identification and quantification of polycyclic aromatic hydrocarbons (PAHs) in aerosols. It was also compared with the classic multivariate curve resolution-alternating least-squares (MCR-ALS) and the GC-MS-based external standard method. In validation samples, average recoveries of five PAHs were within the range from (96.2 ± 6.8)% to (106.5 ± 4.1)% for ATLD-MCR, near to the results of MCR-ALS ((98.0 ± 1.5)% to (106.7 ± 4.3)%). In aerosol samples, the concentrations of pyrene provided by ATLD-MCR were not significantly different from those of MCR-ALS. The other four PAHs including chrysene, benzo[a]anthracene, fluoranthene and benzo[b]fluoranthene were not detected by ATLD-MCR and the GC-MS-based external standard method. The results of figures of merit further demonstrated that ATLD-MCR achieved high sensitivities (8.9 × 104 to 1.7 × 106 mAU ml µg−1) and low limits of detection (0.003 to 0.087 µg ml−1), which were better than or similar to MCR-ALS, presenting a great choice to deal with complex GC-MS data for the simultaneous determination of targeted PAHs in aerosols.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Xiao-Xue Jiang,Li-Qing Yu,Yue-Na Sun,Yuan Li,Hui-Min Li,Yun-Kai Lv
In this work, we reported the preparation of the hollow zeolitic imidazolate framework-7 (ZIF-7) via etching ZIF-7 with tannic acid , and further fabricated the hollow ZIF-7 coated fiber for the solid phase microextraction (SPME) of the five volatile biomarkers (acetone, isopropanol, hexanal , hexanol and decanal) generated from breast cancer cell lines. The hollow structure not only endowed higher extraction performance for the SPME of analytes, but also improved the diffusion rate of the analytes inside the hollow ZIF-7. Under the optimal conditions, the hollow ZIF-7 coated fiber offered high extraction capacity (25–153 mg g −1 ) and enhancement factors (EFs, 2023–11250) for the five biomarkers, good linearity (R 2 > 0.9918) of acetone and isopropanol (2.5–500 μg L −1 ) and hexanol, hexanal, and decanal (1.0–100 μg L −1 ), low limits of detection (S/N = 3) of 0.07–0.53 μg L −1 and the limit of quantifications (LOQs, S/N = 10) of 0.23–1.76 μg L −1 . The precisions (RSDs, %) for intra-day (n = 6), inter-day (n = 5) and fiber-to-fiber (n = 6) were 2.8–7.5%, 4.3–8.5%, and 4.2–14.6%, respectively. The high EFs of the hollow ZIF-7 coated fiber for the five biomarkers resulted from the integrated effects of the large surface area, the unique porous structure, hydrophobic interaction, gate-opening effect, and enhanced properties after etching including faster mass transport, multiple active components, and more exposed active sites. The fabricated hollow ZIF-7 coated fiber lasted at least 140 cycles of extraction/desorption/aging without obvious decrease of extraction ability and no change of crystal structure. Finally, the hollow ZIF-7 coated fiber combined with GC-FID had been successfully used to detect the five biomarkers in the headspace gas of human breast cancer cell lines (MDA-MB-231) and normal mammary cell lines (CCD-1095Sk) with the recoveries of 84–105%. These results revealed the prospect of hollow MOFs as efficient adsorbents for sample pretreatment .
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Shan-Shan Zhang,Sen Guo,Zhao-Jing Zheng,Shao-Jing Liu,Yu-Fei Hou,Chi-Tang Ho,Nai-Sheng Bai
Volatiles in four Allium tenuissimum flower samples were detected and characterized by headspace-gas chromatography-olfactometry-mass spectrometry, and odor activity values. The key aroma compounds were determined by combining the sensory analysis with the omission and recombination experiments. The results illustrated that a total of 36 volatiles were identified and divided into six types, including sulfur-containing compounds, aldehydes, alcohols, ketones, nitrogen-containing compounds, and others. The sulfur-containing compounds and aldehydes were the two most abundant compounds in A. tenuissimum flower. The volatiles were quantified through authentic reference compounds, and the contents of these compounds in four A. tenuissimum flower samples were obtained. Five key aroma compounds of A. tenuissimum flower were confirmed as dimethyl disulfide, dimethyl trisulfide, linalool, 2-methylbutanal, and nonanal. Among these, the predominant compounds dimethyl disulfide and dimethyl trisulfide having strong onion and sulfur aroma, significantly contributed to the aroma of A. tenuissimum flower. The main aroma profiles of A. tenuissimum flower were onion, sulfur, flower, green and burnt. The closer the geographical location and environment of A. tenuissimum flower growth are, the more similar their chemical composition.
✓ 已验证
产品关联
DOI
高影响因子
Environmental Technology & Innovation
·
2021
·
IF 5.263
Juzheng Sun,Yangrui Huang,Huaizheng Li,Yiming Qiu,Jie Zhang,Kun Hu,Jiaying Li,Yuzhu Ding
Ammonia nitrogen (TAN) accumulated in the hydrosphere is an undesired nitrogen pollution and poses a great threat to both the ecological environment and human health. Its removal from water by the photocatalyst directly using solar energy is of strong interest in environmental remediation. In this study, graphitic carbon nitride (g- C 3 N 4 ) was combined with multiwall carbon nanotubes (CNTs) and loaded with silver nanoparticles (Ag (NPs) ) to hydrothermally synthesize a photocatalytic composite (Ag (NP) -(g- C 3 N 4 )/CNT) with a high catalytic efficiency. Characterization analyses indicated even deposition of Ag (NPs) onto (g-C 3 N 4 )/CNT composite by photochemical reduction and the increased photoresponse property compared with raw g-C 3 N 4 and TiO 2 -based materials. The photocatalysis of the composite was evaluated in terms of different Ag (NP) weight ratios, light intensities , photocatalyst dosages, solution pH values and light types. Results showed that a strong alkaline system induced a higher photocatalytic removal of TAN. The TAN removal ratio and rate constant at the optimal pH of 11 were 11.3 and 44.3 times those at a pH of 7. Compared with the process using g- C 3 N 4 alone (dosage = 0.5 g/L, initial TAN = 2.0 mg/L, pH = 11, Ag (NP) = 1 . 0 wt%), Ag (NP) -(g- C 3 N 4 )/CNT composite had effectively increased TAN removal and N 2 conversion ratios from 42.5% and 3.7% to 88.2% and 78.7 % upon 6-h Xe lamp irradiation (180 mW/cm 2 ). Ag (NP) -(g-C 3 N 4 )/CNT composite also exhibited satisfactory stability in cyclical TAN removal. Moreover, the mechanisms of TAN removal were analyzed. This study highlights the application of the Ag (NP) -(g-C 3 N 4 )/CNT composite as a potential method for ammonia removal in environmental remediation.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 8
·5041-5052
·
IF 3.553
Hu Leqi,Jia Fuchao,Wang Shuo,Shao Xingyan,Wang Xiaomei,Sun Yuping,Yin GuangChao,Zhou Tong,Rajan Ramachandran,Feng Zhenyu,Liu Bo
In the present study, the nano-composite of Co-doped g-C 3 N 4 and ZnO (Co–C 3 N 4 /ZnO) sensor was successfully prepared by using solid-phase precursor synthesis method. The crystalline phases were analyzed by X-ray diffraction (XRD), the microstructure of Co–C 3 N 4 /ZnO sensor was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the chemical bonding states were analyzed by X-ray photoelectron spectroscopy (XPS). The gas sensing performance of Co–C 3 N 4 /ZnO sensor was systematically studied and compared with other sensors at the operating temperature of 200–370 °C, and the highest response was observed at 370 °C. Interestingly, Co–C 3 N 4 /ZnO sensor exhibited better response to o-xylene, m-xylene and p-xylene compared with other BTEX gases tested in this study; especially about 11 times higher response was observed against p-xylene compared with pure ZnO sensor at 370 °C. In addition, this sensor showed good stability and repeatability even after 14 weeks with a response/recovery time of 2 s/2 s. The improved gas sensing performance of this sensor was attributed to the formation of more active sites and more number of active oxygen species on the surface of ZnO. Based on these results, it could be ideal to explore Co–C 3 N 4 /ZnO sensor for the rapid detection of BTEX gases, specifically for p-xylene, in the surrounding environment.
✓ 已验证
产品关联
DOI
高影响因子
BIOTECHNOLOGY & BIOTECHNOLOGICAL EQUIPMENT
·
2021
·
IF 1.632
Shuai Xiao,Hai-ou Li,Meng-wei Xu,Ke Huang,Zhou-fei Luo,Lang-tao Xiao
Fatty acids (FAs) in oilseeds are important for human health. Gas chromatography-mass spectrometry (GC-MS) is a popular analytical technology for FAs measurement. FAs need to be derivatized into fatty acid methyl esters (FAMEs), which is essential for GC-MS analysis. The previous methods for methylation of FAs usually include reaction at high temperature and need specific vessels, for which samples with a large scale cannot be analyzed in a short time, leading to low efficiency. Here we report a high-throughput method for profiling fatty acids in plant seeds based on one-step acid-catalyzed methylation followed by GC-MS. This method for FA methylation via derivatization by sulfuric acid with methanol (5%, v/v) and incubation at 64 °C for 4 h in a more convenient 2 mL tube, is efficient. Satisfactory methodological performance was achieved by optimization of the parameters. Only 5 mg seeds were needed as a microscale sample usage by this method. The method is a successful approach to increase the efficiency of sample preparation and analysis for large-scale experiments.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2020
·
IF 4.049
Jiayang Zhang,Birong Zhang,Xueping Dang,Zhiyong Song,Yuling Hu,Huaixia Chen
A Poly (3,4-ethylenedioxothiophene) (PEDOT)/UiO-66 composite was electrodeposited on an etched stainless-steel wire as head-space solid-phase microextraction (HS-SPME) coating. A robust, well controlled thickness, and uniform coating of metal organic framework composites can be realized by the electrodeposited strategy. The incorporated UiO-66 not only enhanced the uniformity and stability of the composite coating, but also effectively decreased the stacking phenomenon of PEDOT and improved its extraction efficiency, which was over 100 times higher than that of the PEDOT coating without UiO-66. The composite coating was used to enrich seven types of volatile organic compounds (VOCs) in ion-exchange resins, including methyl cyclohexane, benzene, toluene, ortho-xylene, styrene, para-xylene and divinyl-benzene. The results of adsorption isotherm analysis showed that π stacking effect played dominant role between the composite coating and VOCs in the extraction process. The composite coating was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared and thermogravimetric analysis, respectively. A determination method for seven kinds of VOCs was established by HS-SPME coupled with gas chromatography-flame ionization detection (GC-FID). Under the optimal experimental conditions, the detection linear range (LRs) was 0.09-100 ng mL −1 , and the detection limit (LODs) was 0.03-0.06 ng mL −1 (S/N = 3). The method was applied for the migration detection of VOCs in four types of ion-exchange resin, which showed satisfactory recovery (84.5-117.2%).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POULTRY SCIENCE
·
2020
·
IF 2.659
Wensheng Yao,Yingxuan Cai,Dengyong Liu,Zhinan Zhao,Zhenghao Zhang,Shuangyu Ma,Mingcheng Zhang,Hao Zhang
This article presents investigation of the flavor profile on 5 different regional Chinese smoked chicken samples using gas chromatography−ion mobility spectrometry analysis methods. Five batches of samples were obtained over the course of 6 mo. A total of 34 flavor substances were identified in the 5 smoked chicken samples, including 10 aldehydes, 7 alcohols, 4 ketones, 2 hydrocarbons, 3 heterocyclic compounds, 4 esters, 2 ethers, and 2 phenolic compounds. The whole spectral fingerprint visually displayed flavor differences and relations in 5 types of smoked chicken with local characteristics. Moreover, the orthogonal projections to latent structures discriminant analysis model revealed that these samples could be separately classified into 5 groups. Multivariate statistical analysis showed that 20 chemicals with higher Variable Importance for the Projection values were the key contributors to the differences of flavor in these 5 kinds of smoked chicken. N-nonanal, heptanal, n-nonanal, heptanal, furfurol, and hexanal were the main common flavor compounds in the 5 types of Chinese smoked chicken, whereas linalool, alpha-terpineol, 1,8-cineole, and anethole were the main characteristic flavor compounds of Goubangzi chicken (No. 1); gamma-butyrolactone, 2-acetylfuran, 2-methoxyphenol, 2-acetylpyrrole, and limonene were determined as the key flavor compounds of Liaocheng chicken (No. 2); the concentration of octanal and n-nonanal was higher in Tangqiao chicken (No. 3); butyl acetate was the key contributor to the flavor compounds of Jinshan chicken (No. 4). 2-Heptanone and 2-pentylfuran had a high correlation with Zhuozishan chicken (No. 5). The different raw materials and ingredients used, especially the method of preparation and cultural differences, in different regions of the country in China were the main reasons leading to the similarities and differences of volatile compounds in the 5 kinds of Chinese traditional smoked chicken.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2019
·Vol. 43
·期 5
·896-904
·
IF 2.516
Yuan Tian,Yuxia Hou,Quan Yu,Xiaohao Wang,Mengkui Tian
In this study, a new covalent organic framework, consisting of tetra(4-aminophenyl)porphyrin and tris(4-formyl phenyl)amine, was layer-by-layer immobilized on stainless-steel wire as a coating for microextraction. The fabrication process was easy and controllable under mild conditions. The as-grown fiber was applied to extract polycyclic aromatic hydrocarbons in aqueous solution via head-space solid-phase microextraction. Furthermore, it was analyzed by gas chromatography with a flame ionization detector. A wide linear range (0.1–50 µg/L), low limits of detection (0.006–0.024 µg/L, signal-to-noise ratio = 3), good repeatability (intra-fiber, n = 6, 3.1–8.50%), and reproducibility (fiber to fiber; n = 3, 5.79–9.98%), expressed as relative standard deviations, demonstrate the applicability of the newly developed coating. This new material was successfully utilized in real sample extraction with a satisfactory result. Potential parameters affecting the extraction efficiency, including extraction temperature and extraction time, salt concentration, agitation speed, sample volume, desorption temperature, and time, were also optimized and discussed.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Tao Liu,Xiaoxue Yuan,Gang Zhang,Jing Hu,Jing An,Tong Chen,Gongying Wang
In this study, a fast and sensitive method based on stir bar sorptive extraction (SBSE) and two-step thermal desorption coupled with online gas chromatography-mass spectrometry was established to simultaneously analyse six trace byproducts [phenyl salicylate (PS), xanthone (XA), methyl o -hydroxybenzoate (MS), 2-methyl diphenyl carbonate (PTC), methyl o -methoxybenzoate (MSME) and phenyl o -methoxybenzoate (PSME)] generated in the process of diphenyl carbonate (DPC) synthesis. Analytes were enriched with multiple sorptive stir bars simultaneously, followed by thermal desorption, cryo-focusing, and instantaneous injection, effectively solving such problems as long adsorption time and small sample volumes compared with conventional stir bars. The main factors influencing SBSE and thermal desorption were studied. Optimized stir bar extraction conditions are as follows: the volume fraction of methanol is 10%, the extraction time is 6 min, and the stirring rate is 1200 rpm at room temperature (25 °C). Optimized two-step thermal desorption conditions are as follows: in the first desorption step, the desorption temperature is 300 °C, the desorption time is 10 min, and the valve and transmission line temperature is 200 °C; in the second desorption step, the cold trap temperature is −10 °C, which is increased at a rate of 100 °C/s to 320 °C and held for 5 min. A splitless mode and a split mode with a split ratio of 20:1 are used in the first and the second desorption step, respectively. Under the optimal conditions, the six byproducts generated in the synthesis of DPC via transesterification were quantitatively analyzed by external standard method. The results showed that, within the range of 1.0−100 ng/L for all of the six transesterification byproducts, this method revealed good linearity with correlation coefficients (r) ≥0.997. The limits of detection (LODs) were between 0.054 ng/L and 0.253 ng/L, the relative standard deviations (RSD) were from 5.2% to 11.5%, and the recoveries were 81.6%−102.6% ( n = 3). The method is simple, rapid and has a wide linear range, high accuracy, and sensitivity, as well as good stability. It is suitable for simultaneous, rapid and selective analysis of six trace byproducts in the process of DPC synthesis. It can also provide vigorous data support and industrialization guidance for the selection of transesterification conditions and research on the formation mechanisms, distribution regularity, and even control of transesterification byproducts.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Wen-Chao Deng,Hai-Long Qian,Cheng Yang,Shu-Ting Xu,Xiu-Ping Yan
Covalent organic frameworks (COFs) are promising as stationary phases for gas chromatography (GC). The successful anchoring of COFs to the inner walls of the capillary with good uniformity is an important prerequisite to ensure the excellent separation performance of columns. However, current methods for the fabrication of COF-based capillary columns cannot always meet this requirement when faced with different COFs, which hampers the further development of COF-based GC stationary phases. Here, we show a general two-step method for the fabrication of COF-bound capillary column. The first step enables the formation of uniform amorphous polymer layer on the inner walls of capillary, while the second step allows the facile transformation of the amorphous polymer layer into a highly crystalline COF layer. COF-bound capillary columns with different framework structures were fabricated successfully by the developed two-step method. Impressively, the COF layers bound on the inner walls of these capillary columns showed good uniformity and high crystallinity. More importantly, as an example, the fabricated Tab-DHTA-bound capillary column showed good resolution (R > 1.5) and high column efficiency (700–39,663 plates m–1) for the tested isomers of ethylbenzene, xylene, dichlorobenzene, chlorotoluene, pinene, 1,3-dichloropropene, and propylbenzene with good precision (RSD, run-to-run, n = 5) (retention time, 0.2–0.6%; peak area, 0.5–1.1%; and peak height, 0.5–1.4%). In general, the fabricated Tab-DHTA-bound capillary column exhibited better performance for the separation isomers than commercial columns DB-5 and HP-FFAP. These results indicate that the two-step method is an efficient way to fabricate the COF-bound capillary column with excellent separation performance.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2023
·Vol. 44
·期 12
·8389-8402
·
IF 5.2
Dongxia Li,Qiong Lin,Lingli Liu,Xuan Song,Zhongxin Wang,Xiangfeng Sun,Yuxin Xue,Yulin Fu,Yuanhao Shi,Zhiqi Li,Xuefeng Gui,Kai Xu
The incorporation of two-dimensional layered metal hydroxides (LDHs) into nonpolar silicone rubber (SR) is not yet universal, mainly because of their originally hydrophilic surface and limited interlamellar galleries that make nanoparticle dispersion and intercalation of polymer segments more difficult. In this work, we develop a modified Ca-Mg-Al LDH form by conjugating the ternary Ca-Mg-Al LDH with silsesquioxane (SQ) surfactants containing benzoic acid moieties and polyethylene glycol chains via an in-situ intercalation process. The bulky anions conjugation to the hydroxide layers dictated both the surface hydrophobicity and interlayer spacing of the modified Ca-Mg-Al LDH, enabling strong inter-constituent interactions within the nanocomposites as well as extensive polymer penetration after incorporation into the SR matrix. The SR/modified LDH nanocomposites show excellent thermal stability and satisfactory mechanical properties due to the homogeneous dispersion and good compatibility of modified Ca-Mg-Al LDH. Moreover, we have observed that the shear-induced orientation of the nano-layered particles upon application of stress imparts a more notably decreased SR/LDH-SQ-40 gas transmission rate (reduced by 55% with respect to that in the unstretched composite films). This result also corroborates the better interfacial bonding and highly efficient load transfer between silsesquioxane-modified LDH and polymer in melt extrusion mixing of such composites. Highlights Modified Ca-Mg-Al LDH with increased layer spacing and reduced hydrophilicity. Modifier enhanced the interfacial adhesion between Ca-Mg-Al LDH and SR matrix. SR/modified LDH showed excellent thermal stability and mechanical properties. Orientation and exfoliation enhanced gas barrier properties of SR/modified LDH.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）