MOLECULES
·
2022
·Vol. 27
·期 21
·7636
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IF 4.927
Xuyan Fan,Tao Tang,Song Du,Ningning Sang,Hao Huang,Chenghui Zhang,Xueping Zhao
A rapid, efficient, simple, and high-throughput method for the simultaneous determination of 108 pesticide residues in three traditional Chinese medicines (TCMs) was established, comprising an improved QuEChERS method in combination with HPLC-MS/MS based on mixed samples. A quantity of 10 mL of acetonitrile was used as extraction solvent, and 10 mg of amino-modified multi-walled carbon nanotubes (MWCNTs-NH2) and 150 mg of anhydrous magnesium sulfate (MgSO4) were selected as sorbents for dispersive solid phase extraction. The performance of the method was verified according to the analytical quality control standards of SANTE/11813/2017 guidelines. With good linearity (R2> 0.9984) in the range of 2–200 μg/L for all pesticides in the selected matrices, and good accuracy, precision, and high sensitivity, the recoveries were in the range of 70–120% for more than 95% of the pesticides, with a relative standard deviation (RSD) of less than 16.82% for all. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.01–3.87 μg/kg and 0.07–12.90 μg/kg, respectively, forFritillaria thunbergiiMiq (F. thunbergii),Chrysanthemum MorifoliumRamat (C. morifolium), andDendrobium officinaleKimura et Migo (D. officinale). The method was successfully applied to 60 batches of actual samples from different regions.Keywords:pesticide residue;QuEChERS;MWCNTs-NH2;traditional Chinese medicines
研究领域:
分析化学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Congcong Yu,Dongyu Hao,Qiao Chu,Ting Wang,Songnan Liu,Tao Lan,Fenghe Wang,Canping Pan
Tea polyphenols, chlorophyll and lutein generally cause strong matrix effects and challenge analysis of trace substances in tea. Seven frequently used adsorbents were chosen to test removal ability for tea polyphenols, chlorophyll and lutein based on the adsorption isotherm fitting. Results showed that MWCNTs-NH 2 demonstrated the strongest removal ability, which may be ascribed to the π-π and electrostatic interaction. Then a method of MWCNTs-NH 2 modified QuEChERS coupled with HPLC-MS/MS detection of 10 organophosphorus pesticide residues in tea was developed and validated. Unlike traditional QuEChERS, only one adsorbent (MWCNTs-NH 2 ) was applied in this method to replace the combined effect of various adsorbents, which improved the easiness and generality of the method. The LOQs were 1.7–9.0 µg/kg. The average recovery rate ranged from 72% to 116% with RSDs less than 14%. This study provides a targeted strategy to develop analysis method for trace substances in a complicated matrix.
研究领域:
分析化学
·
食品科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2022
·
IF 3.428
Haiyan Lan,Linyu Wang,Suwu Liu,Yong Qian,Tianxiang Jin,LiMin Lu
Herein, MnO 2 nanosheets with good catalytic performance and MWCNTs-NH 2 with good conductivity were combined to form MnO 2 /MWCNTs-NH 2 composite with synergistic conductivity and catalytic performance. Subsequently, a novel PAR electrochemical sensor was constructed based on MnO 2 /MWCNTs-NH 2 composite. Some important conditions such as enrichment time, pH value of PBS and modification volume of MnO 2 /MWCNTs-NH 2 were optimized to obtain the best detection performance for PAR. The synergistic catalytic effect of MWCNTs-NH 2 and MnO 2 endowed the composite with good catalytic performance toward the oxidation of PAR. The sensor presented a wide linear range from 0.001 to 20 μM and a low detection limit of 1 nM. Additionally, the sensor exhibited satisfactory reproducibility, repeatability, stability, selectivity, and was successfully applied for the detection of PAR in urine samples.
研究领域:
分析化学
·
材料科学
·
药物分析
✓ 已验证
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Xuelian Liu,Qian Li,Yuying Zheng,Weijie Zheng
Antistatic nylon-6 (PA6) composites have attracted considerable attention due to their tailored properties for electronics, textiles, and automotive applications. In this paper, the antistatic PA6 composites comprising with polypropylene (PP), aminated multi-walled carbon nanotubes (MWCNTs-NH 2 ) and aminated carbon black (CB–NH 2 ) were prepared by melt blending and compression molding. In the composite system, PP was used as the co-matrix to assist the phase separation of PA6. MWCNTs-NH 2 and CB-NH 2 were introduced as conductive fillers. All composites showed good thermal stability with the T 5 % higher than 376 °C and the composites containing fillers showed higher residues after thermal degradation due to the good thermal stability of MWCNTs-NH 2 and CB-NH 2 . The DSC and XRD results indicated that the crystallization properties of the composite materials were determined by PA6 and PP rather the conductive fillers. In general, the introduction of conductive fillers decreased the mechanical properties but effectively improved the conductivity of the composites and then the antistatic properties. Besides, the antistatic analysis and mechanical test denoted that MWCNTs-NH 2 and CB-NH 2 showed synergistic effect on improving the antistatic and mechanical properties of the composites, which was more evident at high MWCNTs-NH 2 quantity. The micromorphologies obtained by SEM first confirmed the ductile fracture of these composites, and then disclosed a two-phase structure of PA6 and PP polymer matrix, where the conductive fillers were found in the PA6 phase. Considering both mechanical and antistatic properties, the composite (PCNB-3) containing both 3 phr MWCNTs-NH 2 and CB-NH 2 was proposed for the antistatic PA6 composite.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2019
·
IF 5.77
Zhen Zhang,Ming Cao,Peng Chen,Bin Yang,Bin Wu,Jibin Miao,Ru Xia,Jiasheng Qian
In this study, selective distribution of amino-functionalized multi-walled carbon nanotubes (MWCNTs-NH 2 ) in poly (vinylidene fluoride)/polyamide 6 (PA6/PVDF) blends is achieved via the mixing process and subsequent migration. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selective extraction confirmed that MWCNTs-NH 2 could migrate from the PVDF phase to the two-phase interface. The composites could significantly improve thermal/electrical conduction capacity of the composites with low dose. The thermal infrared characterization also indicated that the composites have better heat absorption capability and dissipation performance due to the good thermal conductivity . Rheological measurements exhibited the MWCNTs-NH 2 could form network structure with a low content at the interface of the composites. Moreover, the addition of MWCNTs-NH 2 led to an improvement in the mechanical properties compared with the pure PA6/PVDF blends. These results manifest that the thermal/electrical conductivity and mechanical performance of the composites with low filler loading can be significantly improved by selective distribution of MWCNTs-NH 2 through controlling the migration process.
研究领域:
材料科学
·
复合材料
✓ 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）