Foods
·
2023
·Vol. 12
·期 15
·2875
·
IF 5.2
Yibo Dong,Xiaolong Yao,Wanping Zhang,Xiaomao Wu
3,4-dichloroaniline (3,4-DCA) and 3,5-dichloroaniline (3,5-DCA) are, respectively, the primary metabolites deriving from the breakdown of phenylurea herbicides and dicarboximide fungicides in both soils and plants, whose residues in vegetable products have a heightened concern considering their higher health risks to humans and greater toxicity than the parent compounds in the environment. In this study, a sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous determination of 3,4-DCA and 3,5-DCA residues in chive products based on the optimization of HPLC-MS/MS chromatographic and mass-spectrometric conditions using the standard substances and the modified QuEChERS preparation technique. The preparation efficiency of 3,4-DCA and 3,5-DCA from chive samples showed that acetonitrile was the best extractant. The combination of the purification agent graphite carbon black + primary secondary amine and the eluting agent acetonitrile + toluene (4:1,v/v) had a satisfactory purification effect. The linear correlation coefficients (R2) were more than 0.996 with the six concentration range of 0.001–1.000 mg/L for 3,4-DCA and 3,5-DCA. The limit of detection and limit of quantitation of this method was 0.6 and 2.0 µg/kg for 3,4-DCA, as well as 1.0 and 3.0 µg/kg for 3,5-DCA, respectively. The matrix effect range of 3,4-DCA and 3,5-DCA in chive tissues was from −9.0% to −2.6% and from −4.4% to 2.3%, respectively. The fortified recovery of 3,4-DCA and 3,5-DCA in chive samples at four spiked levels of 0.001–1.000 mg/kg was 75.3–86.0% and 78.2–98.1%, with the relative standard deviation of 2.1–8.5% and 1.4–11.9%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.6, 2.0, and 1.0, 3.03 for 4-DCA and 3,5-DCA, respectively. This study highlights that the analytical method established here can efficiently and sensitively detect residues of 3,4-DCA and 3,5-DCA residues for monitoring chive products. The method was successfully applied to 60 batches of actual vegetable samples from different regions.Keywords:3,4-dichloroaniline;3,5-dichloroaniline;simultaneous determination;UPLC-MS/MS;chive
研究领域:
分析化学
·
食品安全
·
环境科学
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产品关联
DOI
PubMed
高影响因子
Catalysts
·
2024
·Vol. 14
·期 10
·724
·
IF 3.8
Nannan Zhan,Yan Xiao,Xingkun Chen,Yuan Tan,Yunjie Ding
In this study, carbon materials with different dimensions, including the typical one-dimensional (1D) carbon nanotube (CNT), two-dimensional (2D) graphene (GF), and three-dimensional (3D) activated carbon (AC), were investigated as a support for Pt catalysts for the selective hydrogenation of 3,4-dichloronitrobenzene (3,4-DCNB) to 3,4-dichloroaniline (3,4-DCAN). Notably, the Pt/CNT catalyst with the lowest dimension exhibited the best conversion of 3,4-DCNB under mild reaction conditions, followed by Pt/GF. Comprehensive characterizations, including XRD, TEM, XPS, and in situ CO DRIFTS, reveal that the dimension of carbon supports plays an important role in the particle size and electronic properties of Pt species, consequently affecting the catalytic performances of Pt catalysts. According to the results, electron-deficient Pt particles with small sizes are more favorable for the hydrogenation of 3,4-DCNB to 3,4-DCAN. In addition, dynamic tests and in situ DRIFTS of 3,4-DCNB indicated that the carbonaceous supports will largely influence the adsorption and activation capacity of the Pt catalysts, so that Pt loaded on CNT and GF are superior to that on the AC. We believe this study will provide good guidance for designing efficient carbon-supported metal catalysts for selective hydrogenation.
研究领域:
化学工程
·
催化科学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2013
·Vol. 160
·期 10
·H742
·
IF 2.588
Xiaowen Du,Pan Zhan,Ning Gan,Yuting Cao,Tianhua Li,Weiguo Sang,Lihong Wang
This paper developed an electrochemiluminescence (ECL) method for detecting ultratrace levels of the highly toxic organic pollutant, 3,4-dichloroaniline (3,4-DCA), in water. This method has not been used previously for 3,4-DCA detection, and is based on a 96-well micro-plate modified with molecularly imprinted sol-gel films combined with multi-walled carbon nanotubes (MIF-MWCNTs). The increase in the ECL signal intensity was proportional to the 3,4-DCA concentration within a certain range, and an excellent response was obtained for 3,4-DCA concentrations ranging from 4 × 10−11 to 6 × 10−9 mol L−1, with a low detection limit (LOD) of 1 × 10−11 mol L−1. The detection sensitivity of the present method is higher than those of the most commonly used chromatography methods, with the recovery of 3,4-DCA from spiked samples of water ranging from 83.3 to 110.5%. Thermodynamic analysis showed that the adsorption of 3,4-DCA by the MIF-MWCNTs occurred spontaneously as an exothermic and entropy decreasing process (ΔH = −32.49 kJ mol−1, ΔS = −117.89 J mol−1). Kinetic equation fitting demonstrated that the adsorption of 3,4-DCA could be fitted by an intraparticle diffusion model, and that the adsorption isotherm data fitted the Freundlich model.
研究领域:
环境科学
·
分析化学
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产品关联
DOI
高影响因子
Journal of Flow Chemistry
·
2021
·Vol. 12
·期 1
·121-129
·
IF 2.786
Duan Xiaonan,Yin Jiabin,Feng Aoxing,Huang Mengmeng,Fu Weisong,Xu Wanfu,Huang Zhenfu,Zhang Jisong
The selective hydrogenation of halogenated nitroaromatic compounds is of great importance in the fine chemical industry. However, the hydrogenation reactions in commonly utilized batch reactors suffer from the undesired dehalogenation, resulting in higher requirement for subsequent separation processes and severe corrosion to industrial fatalities. In this work, a H-flow system with the micropacked bed reactor was developed for the selective hydrogenation of halogenated nitroaromatic compounds and the reduction of 3,4-dichloronitrobenzene was selected as the model reaction. With the optimal hydrogenation conditions, the yield of 3,4-dichloroaniline was obtained as high as 99.8% under mild conditions. With this strategy this flow system was successfully employed to the reduction of other chlorinated nitroaromatics also demonstrating low dehalogenation. The H-flow system enables negligible dehalogenation and remarkable yield of target product with higher efficiency and lower energy cost compared with the batch reactor.
研究领域:
化学工程
·
精细化工
✓ 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）