RAPID COMMUNICATIONS IN MASS SPECTROMETRY
·
2017
·Vol. 32
·期 4
·342-348
·
IF 1.998
Mengmeng Chen,Guohua Zhu,Jiaxiang Xu,Huarong Zhang,Jinsong Liu,Kezhi Jiang
Rationale Carcinogenic o -methylaniline is one of the banned aromatic amines in azo dyes, but it is very difficult to distinguish it from its noncarcinogenic isomers due to their identical retention time on chromatography and similar mass spectra. Methods Imidization of the isomeric methylanilines was carried out by treatment with benzaldehyde under mild conditions. The formed derivatives were analyzed by gas chromatography/mass spectrometry (GC/MS). Theoretical calculations were carried out on the Gaussian 03 program by using the density functional theory method at the B3LYP/6-311+G(d,p) level. Results Imidization of methylanilines occurred easily and gave rise to the corresponding N -methylbenzylidene benzenamines. The isomeric derivatives were completely separated by GC, and thus the three isomeric methylanilines could be determined simultaneously. Due to the ortho effect, the derivative from o -methylaniline has a characteristic fragment ion at m/z 118 with a stable bicyclic structure, and it could be easily differentiated from the meta - and para -isomers in electron ionization mass spectrometry. Conclusions These results provided a promising solution for simultaneous determination of isomeric methylanilines.
研究领域:
化学
·
毒理学
·
分析化学
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DOI
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2025
·
IF 2.1
Ruojing Song,Yuxi Sun
A hydrazone compound 4-hydroxy-N’-(2-hydroxy-5-methylbenzylidene)benzohydrazide (HL) was prepared from the condensation reaction of 5-methylsalicylaldehyde with 4-hydroxybenzohydrazide. The compound was characterized by IR, UV-Vis, 1H NMR, and 13C NMR spectra. Reaction of HL with copper nitrate and copper chloride, respectively, afforded two new copper(II) complexes, [Cu2L2(CH3OH)2]·2NO3 (1) and [CuL(DMF)]·Cl (2). The complexes were characterized by IR and UV-Vis spectra. Structures of HL and the complexes were confirmed by single-crystal X-ray determination. The powder X-ray diffraction was performed to verify the purity of the bulk samples of the complexes. The hydrazone compound coordinates to the Cu atoms through phenolate oxygen, imino nitrogen, and carbonyl oxygen. The Cu atoms in complex 1 are in square pyramidal coordination, while that in complex 2 is in square planar coordination. The antibacterial study using the free hydrazone compound and the two copper complexes against both Gram-positive and Gram-negative bacteria are performed, the two complexes showed antibacterial activity against both Gram-positive and Gram-negative bacteria, whereas the free ligand shows no activity.
研究领域:
有机化学
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配位化学
·
微生物学
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2020
·
IF 3.004
Yanshuxian Liu,Yilei Fan,Zhongping Huang,Huijun Liu,Lili Wang,Zhenlu Shen,Ichi Watanabe
A rapid and sensitive method utilizing flash evaporation-gas chromatography/mass spectrometry (FE-GC/MS) has been developed. The method is applicable to determine ketamine (KET), methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA) in human hair. Cut and weighted hair (0.30 mg) was heated at the flash evaporation temperature of 350 °C. KET, MAMP and MDMA were released into a capillary column for GC/MS analysis and produced fragment ions in SIM mode. Validation of the method included evaluation of linearity, sensitivity, accuracy, precision and repeatability. Linearity ranged from 2 to 300 ng/mg for KET in hair and 2 to 200 ng/mg for MAMP and MDMA in hair with the correlation coefficients all greater than 0.998. Limits of detection were 0.7 ng/mg and limits of quantification were 2.0 ng/mg of hair for KET, MAMP and MDMA. The precision ranged from 1.57% to 7.75% for KET, 1.49% to 7.10% for MAMP and 1.84% to 8.31% for MDMA. The recovery ranged from 102.1% to 110.9% for KET, 99.3% to 108.0% for MAMP and 89.5% to 112.6% for MDMA. Six authentic hair samples from known drug abusers and three drug-free hair samples from volunteers who had never used drugs were successfully analyzed. Compared with traditional time-consuming and hair-comsuming pretreatment method, FE-GC/MS was a faster, simpler and low sample consumption method for the determination of KET, MAMP and MDMA in human hair.
研究领域:
毒理学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 12
·3939
·
IF 4.927
Yazhou Qin,Fan Mo,Sen Yao,Yuanzhao Wu,Yingsheng He,Weixuan Yao
Porous noble metal nanomaterials have attracted extensive attention due to their high specific surface area and surface plasmon resonance effect. However, it is difficult to form porous structures due to the high mobility and low reduction potential of noble metal precursors. In this article, we developed a facile method for preparing porous Ag with a controllable structure at room temperature. Two kinds of Ag crystals with different porous structures were successfully prepared by using AgCl cubes as sacrificial templates. Through the galvanic replacement reaction of Zn and AgCl, Ag crystals with a sponge-like porous structure were successfully prepared. Additionally, using NaBH4as the reducing agent, we prepared granular porous Ag cubes by optimizing the amount of reducing agent. Both the sponge-like and granular porous Ag cubes have clean and accessible surfaces. In addition, we used the prepared two porous Ag cubes as substrate materials for SERS detection of five kinds of methamphetamine analogs. The experimental results show that the enhancement effect of granular porous Ag is better than that of sponge-like porous Ag. Furthermore, we probed the hot spot distribution of granular porous Ag by Raman mapping. By using granular porous Ag as the substrate material, we have achieved trace detection of 5 kinds of methamphetamine analogs including Ephedrine, Amphetamine, N-Methyl-1-(benzofuran-5-yl)propan-2-amine (5-MAPB), N-Methyl-1-(4-methoxyphenyl)propan-2-amine (PMMA) and N-Methyl-1-(4-fluorophenyl)propan-2-amine (4-FMA). Furthermore, to achieve qualitative differentiation of analogs with similar structures we performed density functional theoretical (DFT) calculations on the Raman spectra of the above analogs. The DFT calculations provided the vibrational frequencies, Raman activities, and normal mode assignment for each analog, enabling the qualitative differentiation of the above analogs.Keywords:Ag crystal;methamphetamine;SERS;porous structure
研究领域:
化学
·
材料科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Yucheng Zi,Dong Chen,Guochen Wang,Yuhong Ma,Wantai Yang
A simple strategy is proposed to offer styrene (St) copolymer with intrinsic and catalyst-free upcycling capability by incorporating α -methylstyrene (AMS) units into the copolymer poly(AMS -co- St) (PAS). Compared to polystyrene (PS), the PAS is more susceptible to depolymerizing into St and AMS monomers with higher yields at relatively lower temperature. The yield of liquid chemicals of PAS-4 (26.1 mol% AMS) is up to 93 wt% at 380°C, whereas that PS as control is 78 wt%. The reclaimed liquid chemicals of PAS-4 contain 58.4 wt% St and 37.7 wt% AMS, while the chemicals of PS contain 81.8 wt% St and 4.1 wt% AMS. The introduction of AMS units in PAS leads to a reduction in the liquid chemicals other than St and AMS monomers. The blends of PS and PAMS do not demonstrate the synergistic effect regarding facilitating the PS depolymerization. In addition, the properties of the new PASs prepared with the reclaimed monomers are comparable with those of the virgin PASs. This work proves the concept that recycling efficiency could be boosted by incorporating liable structural units into the copolymer chains and demonstrates a closed-loop of PS up-cycling.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 34
·e202403054
·
IF 1.9
Yifei Wang,Ze Wang,Pengfei Qin,Songgeng Li
Graphical Reactivities of 2-methylphenol, 2-methoxyphenol, 4-methylphenol and 4-methoxyphenol with formaldehyde, and the thermal stabilities of the resoles are investigated. The reactivity of ortho phenol is found higher than that of para phenol. The resole of para phenol has a higher thermal stability than that of ortho phenol. The resole of methylphenol generally has a higher thermal stability than that of methoxyphenol. Bio-oil formaldehyde resole (BFR) can be used as adhesive in plywood industry. However, the BFR has a lower thermal stability, and the reason is still unclear. Herein, the reactivities of four representative phenolic compounds in bio-oil, including two ortho phenols (2-methylphenol, 2-methoxyphenol) and two para phenols (4-methylphenol and 4-methoxyphenol), as well as the thermal stabilities of the prepared resoles are investigated. The results show that the reactivity of an ortho phenol is higher than that of a para phenol. The resole prepared from a para phenol has a higher thermal stability than that of an ortho phenol. The resole of an ortho phenol decomposes even when heated at the low temperature of 100 °C. The resole of a methylphenol generally has a higher thermal stability than that of a methoxyphenol. Based on the results, the reason for the low reactivity of bio-oil and the low thermal stability of BFR are speculated.
研究领域:
化学
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材料科学
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生物能源
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产品关联
DOI
高影响因子
ZEITSCHRIFT FUR KRISTALLOGRAPHIE-NEW CRYSTAL STRUCTURES
·
2024
·
IF 0.3
Da-Chun Jiang,Hai-Yuan Zhu
C 9 H 9 Br 3 , monoclinic, P 2 1 (no. 4), a = 8.7420(4) Å, b = 4.4696(2) Å, c = 13.3526(6) Å, β = 97.785(2)°, V = 516.92(4) Å 3 , Z = 2, R
gt
( F ) = 0.0235, wR
ref
( F 2 ) = 0.0528, T = 150 K.
CCDC no.: 2332847
研究领域:
化学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
FORENSIC SCIENCE INTERNATIONAL
·
2014
·
IF 2.115
Binling Zhu,Liang Meng,Kefang Zheng
Recently a new type of mixed drug oral solution has become prevalent in China, the identification and quantitative inspection of which are demanded in conviction and sentencing as well as drug intelligence. In 2013, inspection was carried out on 86 bottles of substances seized in 13 cases with the adoption of GC–MS methodology for qualitative identification and GC–FID for quantitative identification. 94.1% of the samples were light yellow turbid liquid while 95.3% were detected with more than two drugs. Detection rate of methamphetamine, MDMA and ketamine was up to 89.5%, 37.2% and 83.7% respectively. Quantitative inspection results indicated that concentrations of methamphetamine, MDMA , ketamine were 0.04–13 mg/mL, 0.04–29 mg/mL and 0.1–34 mg/mL, respectively. Appearance, composition and drug concentration of samples vary from case to case.
研究领域:
毒理学
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分析化学
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法医学
✓ 已验证
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2021
·Vol. 413
·期 16
·4237-4246
·
IF 4.157
Liu Hui,Xia Lei,Shen Chengyin,Huang Chaoqun,Chu Yannan
Methamphetamine (MA) is a highly addictive and illegal psychostimulant drug and is currently one of the most commonly abused illicit drugs in the world. The on-site rapid detection of trace amounts of MA and screening illicit drugs in clandestine laboratories is important for drug enforcement agencies and the forensic community in general. However, detecting methamphetamine in the presence of nicotine and cigarette smoke by ion mobility spectrometry faces difficulty due to the overlapped spectral peaks of methamphetamine and nicotine. In this work, a new method was developed to detect MA using pyridine as a dopant in the presence of nicotine by a homemade ion mobility spectrometry. The reduced mobilities of MA and nicotine were measured under the temperatures of the drift tube from 40 to 120 °C and doping with pyridine. The result shows that the temperature of 100 °C is beneficial to resolve the two substances. The concentration of doped pyridine is optimized to be 18 ppm. In this doped experiment, the reaction rate of nicotine is higher than that of MA by measuring the instrumental responses of MA and nicotine. No matter how high the nicotine content is, the interference of nicotine can be eliminated in the detection of MA doped with pyridine. This method is also successfully applied for the determination of MA and nicotine simultaneously in real saliva samples. The limit of detection of MA was measured to be about 0.5 ng/μL. The promising results in this work provide an effective method for on-site detection of MA. Graphical abstract
研究领域:
分析化学
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法医学
·
药物检测
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DOI
高影响因子
Catalysts
·
2020
·Vol. 10
·期 6
·664
·
IF 3.52
Keyi Tian,Ruonan Chen,Jiafang Xu,Ge Yang,Xintong Xu,Yanhua Zhang
The lack of understanding of the radical reaction mechanism of Carbon dioxide (CO2) in photo- and electro-catalysis results in the development of such applications far behind the traditional synthesis methods. Using methylbenzophenone as the model, we clarify and compare the photo-enolization/Diels−Alder (PEDA) mechanism for photo-carboxylation and the two-step single-electron reduction pathway for electro-carboxylation with CO2through careful control experiments. The regioselective carboxylation products,o-acylphenylacetic acid and α-hydroxycarboxylic acid are obtained, respectively, in photo- and electro-chemistry systems. On the basis of understanding the mechanism, a one-pot step-by-step dicarboxylation ofo-methylbenzophenone is designed and conducted. Both the experimental results and related density functional theory (DFT) calculation verify the feasibility of the possible pathway in which electro-carboxylation is conducted right after photo-carboxylation in one vessel. This synthesis approach may provide a mild, eco-friendly strategy for the production of polycarboxylic acids in industry.Keywords:photocatalysis;electrocatalysis;photoelectro-chemistry;CO2reduction;methylbenzophenone
研究领域:
有机化学
·
环境科学
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产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2023
·
IF 7.7
Shibo Yuan,Peng Bai,Yi He,Jiafa Chen,Yicheng Zhao,Yongdan Li
Photocatalytic N-formylation of amines with CO 2 is a promising strategy to convert CO 2 into value-added chemicals sustainably. In this work, a black TiO 2 -supported Cu photocatalyst is prepared through a solvothermal method for the N-formylation of N-methylaniline with NaBH 4 as the reducing agent. Cu nanoparticles and oxygen vacancies are formed on the surface of the photocatalyst after reduction with H 2 , which decreases the band-gap energy and promotes the separation of photogenerated electrons and holes, thereby improving the photocatalytic activity remarkably. A 100 % conversion is achieved after 9 h radiation, and the yield of N -methylformanilide reaches 81 %. Both the amount of NaBH 4 and the pressure of CO 2 show important influences on the activity and selectivity of the photocatalytic process, and the carbon and hydrogen in the aldehyde group are from CO 2 and NaBH 4 , respectively. The photocatalyst also shows promising cycling durability.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
ANALYTICAL SCIENCES
·
2019
·Vol. 35
·期 8
·875-882
·
IF 1.618
Wang Xia,Zhai Suyan,Liu Chao,Wang Xiaoshu,Yang Ya,Tu Yifeng
An antibody-based immunotherapy for methamphetamine (MA) addictive treatment is has been drawing more and more attention in recent years. However, studies about methamphetamine antibody (anti-MA) immunodetections are rare, owing to the lack of immunogenicity of small molecule MA. This study provides a simple and effective approach to develop a convenient electrochemiluminescent (ECL) immunosensor for the testing of anti-MA. In short, the synthetic holoantigen of MA is immobilized on a homemade gold nanoparticles modified electrode as the sensing host for the specific recognition and detection of anti-MA. The research suggested, under optimal experimental conditions, the ECL intensity on resultant immunosensor has a wide-linear regression toward the anti-MA quantity within the range from 0.03 to 3.07 ng with a detection limit of 2.32 pg. It responded to the dosage of anti-MA in spiked blood samples with satisfactory recovery. According to the research, the developed sensor shows promise as a portable Anti-MA fast seized device which performs quickly and offers convenience, and will be helpful for forensic identification and clinical treatment.
研究领域:
分析化学
·
生物医学工程
·
法医学
·
药物成瘾研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）