Teffera Y, Baird W M, Smith D L
Department of Medicinal Chemistry and Pharmacognosy, Purdue University, West Lafayette, Indiana 47907.
Anal Chem. 1991 Mar 1;63(5):453-6. doi: 10.1021/ac00005a013.
The level of certain water-soluble hydrocarbon conjugates, such as benzo[a]pyrene sulfates (BP-SO4), is a direct measure of carcinogenic polycyclic aromatic hydrocarbon metabolism and an indication of exposure. A new method, based on continuous-flow high-resolution fast atom bombardment mass spectrometry, has been developed for the analysis of BP-SO4 in the medium of cell cultures treated with benzo[a]pyrene. An organic solvent extract of medium from cultures of the human hepatoma cell line (HepG2) was fractionated by reversed-phase SEP-PAK chromatography and microbore high-performance liquid chromatography (HPLC). The HPLC fraction containing BP-SO4 was collected, dried, and injected into a stream of acetonitrile/water/glycerol that was continuously flowing to the tip of the sample probe which was being bombarded continuously by a beam of high-energy xenon atoms. Molecular anions of BP-SO4 (m/z 347) desorbed from the liquid were analyzed by a high-resolution (m/delta m 5000) mass spectrometer and recorded as a function of time. As little as 1.5 pg of BP-SO4 could be detected with a S/N ratio of 8. The mass spectrometer response was linear with respect to the quantity of BP-SO4 injected over the range from 15 to 625 pg. The results obtained with this method show that the HepG2 cultures metabolized 3% of the benzo[a]pyrene into the BP-SO4 conjugate in 24 h. This procedure, which was used to detect and quantify directly BP-SO4 in culture medium without the use of a radiolabeled precursor, should be generally applicable for analyses of sulfated conjugates resulting from the metabolism of different hydrocarbons.
某些水溶性烃类共轭物的水平，如苯并[a]芘硫酸盐（BP-SO4），是致癌多环芳烃代谢的直接指标，也是暴露的一种指示。基于连续流动高分辨率快原子轰击质谱法，已开发出一种新方法，用于分析用苯并[a]芘处理的细胞培养介质中的BP-SO4。人肝癌细胞系（HepG2）培养物的介质的有机溶剂提取物通过反相SEP-PAK色谱法和微径高效液相色谱法（HPLC）进行分离。收集含有BP-SO4的HPLC馏分，干燥后注入连续流向样品探针尖端的乙腈/水/甘油流中，该样品探针正被一束高能氙原子连续轰击。从液体中解吸的BP-SO4的分子阴离子（m/z 347）由高分辨率（m/Δm 5000）质谱仪进行分析，并作为时间的函数进行记录。在信噪比为8的情况下，可检测到低至1.5 pg的BP-SO4。在15至625 pg的范围内，质谱仪的响应与注入的BP-SO4量呈线性关系。用该方法获得的结果表明，HepG2培养物在24小时内将3%的苯并[a]芘代谢为BP-SO4共轭物。该程序用于直接检测和定量培养基中的BP-SO4，而无需使用放射性标记的前体，通常应适用于分析不同烃类代谢产生的硫酸化共轭物。
