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A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining four tobacco-specific N-nitrosamines (TSNAs) in mainstream smoke from Chinese Virginia cigarettes was developed. Mainstream cigarette smoke particulate matter was collected on a Cambridge filter pad, further extracted using 100 mM ammonium acetate after 100 microL internal(More)
A simple and sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-ESI-MS-MS) method was developed and validated for the quantification of creatinine in human urine. The analysis was carried out on an Agilent Zorbax Eclipse XDB-C18 column (2.1 × 150 mm, 3.5 μm). The mobile phase was 0.1% formic acid in water and 0.1% formic acid in(More)
A method for the determination of three acidic herbicides, dicamba, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in tobacco and soil has been developed based on the use of liquid-liquid extraction and dispersive solid-phase extraction (dispersive-SPE) followed by UPLC-MS/MS. Two percentage of (v/v) formic acid in(More)
A new method for determination of phenoxy acid herbicide residues in tobacco based on the use of liquid extraction/partition and dispersive SPE followed by HPLC/electrospray ionization-MS/MS is reported. Formic acid (2%, v/v) in acetonitrile as the extraction solvent and inclusion of citrate buffer helped partitioning of all analytes into the acetonitrile(More)
In this paper, tobacco mosaic virus (TMV) coated protein (CP) was genetically modified by introducing a hexahistidine tag into it for a well-defined one-dimensional template, on which Au nanocrystals (NCs) were grown. The results showed that genetic modification could not only ameliorate the one-dimensional structure of the template, but also improve the(More)
The World Health Organization Study Group on Tobacco Product Regulation (WHO TobReg) proposed mandated ceilings on 9 prioritized mainstream cigarette smoke constituents determined from the market-specific median of nicotine-normalized yield distributions. Considering the requirements for assessing and reporting of compliance with ceilings, it is of great(More)
A method to determine residues of the three acid herbicides, 2,4,5-trichlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, and 3,6-dichloro-2-methoxybenzoic acid (dicamba), in tobacco using LC/MS/MS is presented. Because these herbicide residues in tobacco might exist in different forms (free acid, salt, and ester), tobacco samples were first(More)
N-nitrosonornicotine (NNN), 4-( methylnitrosamino )-1-(3-pyridyl )-1-butanone (NNK), N-nitrosoanatabine (NAT) and N-nitrosoanabasine (NAB) are the most abundant carcinogens identified in tobacco and tobacco smoke. The accurate quantifications of NNN, NNK, NAT and NAB are necessary to evaluate its impact on the public health. A liquid(More)
A method was developed for the simultaneous extraction and determination of four mercapturic acids (MAs), N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-acetyl-S-(3-hydroxypropyl)-L-cysteine (3-HPMA), N-acetyl-S-(2-carboxyethyl)-L-cysteine ( CEMA) and S-phenylmercapturic acid (SPMA), in human urine using solid phase extraction and high performance(More)
A method of the determination of the carbon-centred radicals in mainstream cigarette smoke using a spin-labelled fluorophore, 4-((9-acridinecarbonyl) amino)-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO-9-AC), as a fluorescent probe is presented. After being producted by smoking in International Organization for Standardization (ISO) mode, the carbon-centred(More)