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881.
Negar Saedi Abdulrahman Bahrami Farshid Ghorbani Shahna Majid Habibi Mohraz Maryam Farhadian Saber Alizadeh 《Biomedical chromatography : BMC》2020,34(4):e4800
The aim of this study was to develop a new method for the determination of benzene, toluene, ethylbenzene and xylene isomers (BTEXs) in urine samples. In this method, MIL-100(Fe)@Fe3O4@SiO2 metal–organic framework was synthesized, characterized and packed inside a needle trap device (NTD) as a sorbent for headspace extraction of unmetabolized BTEXs from urine samples followed by gas chromatography (GC) analysis. The GC device was equipped with a flame ionization detector (FID). The results showed that the optimal extraction time, extraction temperature and salt content were 60 min, 30°C and 5%, respectively. Also, the optimal desorption time and temperature were determined to be 1 min and 250°C, respectively. The limits of detection and quantification of the analytes of interest were in the ranges 0.0001–0.0005 and 0.0003–0.0014 μg ml−1, respectively. The intra- and inter-day repeatability were <7.6%. The accuracy of the measurements in urine samples was in the range 7.1–11.4%. The results also demonstrated that the proposed NTD offered various advantages such as having high sensitivity and being inexpensive, reusable, user friendly, environmentally friendly and compatible for use with the GC device. Therefore, it can be efficiently used as a MIL–NTD for the extraction and analysis of unmetabolized BTEXs from urine samples. 相似文献
882.
Javad Ghafari Masoomeh Vahabi Somayeh Farhang Dehghan Rezvan Zendehdel 《Biomedical chromatography : BMC》2020,34(10):e4924
Monitoring the trace amount of chemicals in various samples remains a challenge. This study was conducted to develop a new solid-phase microextraction (SPME) system (inside-tube SPME) for trace analysis of n-hexane in air and urine matrix. The inside-tube SPME system was prepared based on the phase separation technique. A mixture of carbon aerogel and polystyrene was loaded inside the needle using methanol as the anti-solvent. The air matrix of n-hexane was prepared in a Tedlar bag, and n-hexane vapor was sampled at a flow rate of 0.1 L/min. Urine samples spiked with n-hexane were used to simulate the sampling method. The limit of detection using the inside-tube SPME was 0.0003 μg/sample with 2.5 mg of adsorbent, whereas that using the packed needle was 0.004 μg/sample with 5 mg of carbon aerogel. For n-hexane analysis, the day-to-day and within-day coefficient variation were lower than 1.37%, with recoveries over 98.41% achieved. The inside-tube SPME is an inter-link device between two sample preparation methods, namely, a needle trap device and an SPME system. The result of this study suggested the use of the inside-tube SPME containing carbon aerogel (adsorbent) as a simple and fast method with low cost for n-hexane evaluation. 相似文献
883.
Khodaei Mohammad Mehdi Alizadeh Abdolhamid Haghipour Maryam 《Research on Chemical Intermediates》2020,46(2):1033-1045
Research on Chemical Intermediates - A new 4-aminomethylbenzoic acid-functionalized Fe3O4 magnetic nanoparticles as a hybrid heterogeneous catalyst was synthesised and characterized by FT-IR, XRD,... 相似文献
884.
Mirzaei-Mosbat Maryam Ghorbani-Vaghei Ramin Karamshahi Zahra 《Research on Chemical Intermediates》2020,46(2):1613-1628
Research on Chemical Intermediates - In this research, the synthesis route of ZnCr-layered double hydroxides functionalized with poly(p-phenylenediamine) and Cu(II) was described. LDHs@PpPDA@Cu was... 相似文献
885.
Seyedi Maryam Sadat Sohrabi Mahmoud Reza Motiee Fereshte Mortazavinik Saeid 《Research on Chemical Intermediates》2020,46(3):1645-1662
Research on Chemical Intermediates - A simple and fast method based on activated carbon@nanozerovalent iron–nickel (AC@nZVI/Ni) nanoadsorbent was developed for highly efficient removal of... 相似文献
886.
Martnez-Legaz Juan Enrique Tamadoni Jahromi Maryam Naraghirad Eskandar 《Journal of Optimization Theory and Applications》2022,193(1):107-117
Journal of Optimization Theory and Applications - We investigate convergence properties of Bregman distances induced by convex representations of maximally monotone operators. We also introduce and... 相似文献
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A new Cu(II) immobilized on hyperbranched polyglycerol (HPG) functionalized graphene oxide catalyst was prepared and characterized by FT-IR, TGA, FE-SEM, XRD, and ICP-OES techniques. This catalyst was used efficiently for the preparation of aminonaphthoquinones via one-pot three-component condensation reaction under solvent-free conditions. The catalyst could be easily recovered and reusable several times without a significant loss of activity, which make this method attractive and in a close agreement with green chemistry. 相似文献