Time filter

Source Type

Ma R.,Anhui University of Science and Technology | Cao F.,Anhui University of Science and Technology | Liu B.,Key Laboratory of Cigarette Smoke Research of China National Tobacco Corporation | Hu H.,Anhui University of Science and Technology | Gan W.,Anhui University of Science and Technology

Abstract A novel method of divinylbenzene polymer (DVB)/Fe3O4 hybrid monolithic column solid phase extraction and on line thermal desorption was developed to analyze methylmercury (MeHg) in water and fish samples. The monolithic column was prepared by in situ polymerization in silica tube and its heating characteristic was studied in detail. Special accent was put on the study of parameters influencing adsorption and desorption of MeHg, such as pH, flow rate of sample solution, temperature of desorption and flow rate of carrier. Under optimum conditions, the detection limit and relative standard deviation of MeHg were 0.09 ng L-1 and 2.6% (10 ng L-1, N=11), respectively. Recoveries of MeHg were never less than 96%. Standard reference material GBW10029 was analyzed for validation of the methodology. This method was successfully applied to the determination of MeHg in water and fish samples. © 2015 Elsevier B.V. All rights reserved. Source

Hu H.,Anhui University of Science and Technology | Liu B.,Key Laboratory of Cigarette Smoke Research of China National Tobacco Corporation | Yang J.,Anhui University of Science and Technology | Lin Z.,Anhui University of Science and Technology | Gan W.,Anhui University of Science and Technology
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences

3-Hydroxybenzo[a]pyrene (3-OHBaP) is widely used as a biomarker for assessing carcinogenic benzo[a]pyrene exposure risks. However, monitoring urinary 3-OHBaP suffers from an insufficient sensitivity due to the pg/mL level in urine excretion. In this study, a sensitive method for determination trace urinary 3-OHBaP was developed, involving enzymatic hydrolysis of the glucuronide and sulfate conjugates, ionic liquids dispersive liquid-liquid microextraction (IL-DLLME) enrichment, derivatization with dansyl chloride and HPLC-HRMS/MS analysis in the positive ion mode. Using IL-DLLME makes the enrichment of trace 3-OHBaP very simple, time-saving, efficiency and environmentally-friendly. To enhanced HPLC-HRMS/MS response, an MS-friendly dansyl group was introduced to increase the ionization and fragmentation efficiency. The optimal IL-DLLME extraction parameters and derivatization reaction conditions were investigated. Good linearity was obtained over a concentration range of 0.6-50.0 pg/mL with correlation coefficients (r2) of 0.9918. The limit of detection (LOD) and limit of quantification (LOQ) values were 0.2 pg/mL and 0.58 pg/mL, respectively. The recoveries were 92.0 ± 4.2% with the intra-day and inter-day RSD values ranged from 2.2% to 3.8% and from 3.3% to 6.8%, respectively. The proposed IL-DLLME-Dansylation-HPLC-HRMS/MS method was successfully applied to determine urinary 3-OHBaP of non-occupational exposed smokers and nonsmokers. © 2016 Elsevier B.V. Source

Ding Y.,Hefei University of Technology | Yang J.,Hefei University of Technology | Yang J.,Key Laboratory of Cigarette Smoke Research of China National Tobacco Corporation | Zhu W.-J.,Hefei University of Technology | And 4 more authors.
Journal of the Chinese Chemical Society

An ultra-high-pressure liquid chromatography/MS3 (UPLC-MS 3) method has been developed and validated for the quantitative determination of four major TSNAs in mainstream cigarette smoke using MS 3 scan mode on a hybrid triple quadrupole-linear ion trap mass spectrometer. The new method combining the UPLC with MS3 scanmode offers decreased sample analysis time and good selectivity. Aftermainstream cigarette smoke was collected on a Cambridge filter pad, the particulate matter was extracted with ammonium acetate solution and analyzed by UPLC-MS3 using isotopically labeled analogues as internal standards. Four TSNAs were completely separated on an Agilent XDB-C18 UPLC column using isocratic elution during a 6 min LC run time. Excellent linearity was obtained over the concentration range of 1.0- 150.0 ng/mL for all TSNAs with values for correlation coefficient (r) between 0.9985-0.9994. Limits of detection (LOD) of each TSNA varied from 0.023 to 0.067 ng/mL, and lower limits of quantification (LLOQ) varied from 0.077 to 0.223 ng/mL, respctively. The recovery of each TSNA was from 89.2 to 106.8%. The method achieved excellent reproducibility with RSD 2.1-6.8% for intra-assay and 3.4-9.1% for inter-assay. Thismethod can be used as an effective approach to significantly improve the detection capability for TSNAs in complex matrices. Source

Wang K.,Anhui University | Niu H.,Anhui University | Chen J.,Anhui University | Song J.,Anhui University | And 5 more authors.

A facile and environmentally friendly surface-ion adsorption method using CeCO3OH@C as template was demonstrated to synthesize CeO2-LaFeO3 perovskite composite material. The obtained composite was characterized by X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermo-gravimetric analysis and differential scanning calorimetry (TG-DSC), N2 adsorption/desorption isotherms and X-ray photoelectron spectra (XPS) measurements. The catalytic degradation of nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was tested to evaluate catalytic activity of the CeO2-LaFeO3 composite. Much better activity was observed for the CeO2-LaFeO3 composite comparing with CeO2 and LaFeO3. These results suggested that perovskite composite materials are a promising candidate for the degradation of tobacco-specific nitrosamines (TSNAs). © 2016 by the authors. Source

Yao L.,Hefei University of Technology | Yang J.,Hefei University of Technology | Guan Y.-F.,Hefei University of Technology | Guan Y.-F.,CAS Dalian Institute of Chemical Physics | And 5 more authors.
Analytical and Bioanalytical Chemistry

The tobacco-specific nitrosamine metabolite 4- (methylnitrosamino)-1-(3- pyridyl)-1-butanol (NNAL) is a valuable biomarker for human exposure to the carcinogenic nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in tobacco and tobacco smoke. In this work, an efficient and sensitive method for the analysis of NNAL in human hair was developed and validated. The hair sample was extracted by NaOH solution digestion, purified by C18 solid-phase extraction (SPE) and molecularly imprinted solid-phase extraction, further enriched by reverse-phase ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) into 1.0 % aqueous formic acid, and finally analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry. Good linearity was obtained in the range of 0.24-10.0 pg/mg hair with a correlation coefficient of 0.9982, when 150 mg hair was analyzed. The limit of detection and lower limit of quantification were 0.08 and 0.24 pg/mg hair, respectively. Accuracies determined from hair samples spiked with three different levels of NNAL ranged between 87.3 and 107.7 %. Intra- and inter-day relative standard deviations varied from 4.1 to 8.5 % and from 6.9 to 11.3 %, respectively. Under the optimized conditions, an enrichment factor of 20 was obtained. Finally, the developed method was applied for the analysis of NNAL in smokers' hair. The proposed sample preparation procedure combining selectivity of two-step SPE and enrichment of DLLME significantly improves the purification and enrichment of the analyte and should be useful to analyze NNAL in hair samples for cancer risk evaluation and cancer prevention in relation to exposure to the tobaccospecific carcinogen NNK. © Springer-Verlag 2012. Source

Discover hidden collaborations