Barreto R P, Albuquerque F C, Netto Annibal D Pereira
Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de São João Batista, s/n, 24020-150 Niterói, RJ, Brazil.
J Chromatogr A. 2007 Sep 7;1163(1-2):219-27. doi: 10.1016/j.chroma.2007.06.040. Epub 2007 Jun 27.
A method for determination of nitrated polycyclic aromatic hydrocarbons (NPAHs) in diesel soot by high-performance liquid chromatography-mass spectrometry with atmospheric pressure chemical ionization (APCI) and detection by ion-trap following ultrasonic extraction is described. The determination of 1-nitropyrene that it is the predominant NPAH in diesel soot was emphasized. Vaporization and drying temperatures of the APCI interface, electronic parameters of the MS detector and the analytical conditions in reversed-phase HPLC were optimized. The patterns of fragmentation of representative NPAHs were evaluated by single and multiple fragmentation steps and negative ionization led to the largest signals. The transition (247-->217) was employed for quantitative analysis of 1-nitropyrene. Calibration curves were linear between 1 and 15 microgL(-1) with correlation coefficients better than 0.999. Typical detection limit (DL) of 0.2 microgL(-1) was obtained. Samples of diesel soot and of the reference material (SRM-2975, NIST, USA) were extracted with methylene chloride. Recoveries were estimated by analysis of SRM 2975 and were between 82 and 105%. DL for 1-nitropyrene was better than 1.5 mg kg(-1), but the inclusion of an evaporation step in the sample processing procedure lowered the DL. The application of the method to diesel soot samples from bench motors showed levels <or=1 microg of 1-nitropyrene per gram of diesel soot.
描述了一种通过高效液相色谱-质谱联用技术结合大气压化学电离（APCI）以及超声萃取后离子阱检测来测定柴油烟灰中硝化多环芳烃（NPAHs）的方法。重点阐述了对柴油烟灰中主要的NPAH——1-硝基芘的测定。对APCI接口的汽化和干燥温度、质谱检测器的电子参数以及反相高效液相色谱的分析条件进行了优化。通过单步和多步裂解评估了代表性NPAHs的裂解模式，负离子化产生的信号最强。采用（247→217）的跃迁对1-硝基芘进行定量分析。校准曲线在1至15μg L⁻¹之间呈线性，相关系数优于0.999。获得的典型检测限（DL）为0.2μg L⁻¹。用二氯甲烷萃取柴油烟灰样品和参考物质（SRM-2975，美国国家标准与技术研究院）。通过分析SRM 2975估算回收率，回收率在82%至105%之间。1-硝基芘的检测限优于1.5 mg kg⁻¹，但在样品处理过程中增加一个蒸发步骤可降低检测限。将该方法应用于台式发动机的柴油烟灰样品，结果表明每克柴油烟灰中1-硝基芘的含量≤1μg。
