New shape-selectivity discovered on graphene-based materials in catching tobacco specific nitrosamines.

New shape-selectivity of graphene-based materials was discovered on this article. To explore the new selectivity, the structure and surface state of graphene and carbon nanotube were examined firstly, and their specific selectivity was verified and was compared with that of ZSM-5 zeolite in aqueous solutions of tobacco specific nitrosamines (TSNA) along with dyes. These two adsorbents trapped about 55% and 70% of 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK) but only 3% of N'-nitrosonornicotine (NNN) in solution, having an obvious selectivity for the former, due to its stronger interaction with graphene.

Creating an Optimal Microenvironment within Mesoporous Silica MCM-41 for Capture of Tobacco-Specific Nitrosamines in Solution.

To meet the requirement of capturing tobacco-specific nitrosamines (TSNA) for environment protection, a unique microenvironment was carefully created inside the channels of mesoporous silica MCM-41. In situ carbonization of template micelles at 923 K, combined with the excess aluminum used in one-pot synthesis of MCM-41, is adopted to tailor the tortuosity of mecsoporous channels, while loaded metal oxides (5 wt %) and the Al component in the framework are employed to exert the necessary electrostatic interaction toward the target carcinogens TSNA in solution. The elaborated microenvironment created in mesoporous sorbents was characterized with XRD, N adsorption-desorption, TEM, XPS, and TG-DSC methods.

Development, validation, and application of a liquid chromatography-tandem mass spectrometry method for the determination of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in human hair.

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 C(18) 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.