Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, USA.
Department of Civil, Construction and Environmental Engineering, The University of Alabama, Tuscaloosa, AL, USA.
Rapid Commun Mass Spectrom. 2020 Jun 15;34(11):e8765. doi: 10.1002/rcm.8765.
Polycyclic aromatic hydrocarbons (PAHs) present in oil spill samples are analyzed by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/tandem mass spectrometry (GC/MS/MS) using four different methods: (1) full scan (SCAN), (2) selected ion monitoring (SIM), (3) multiple reaction monitoring (MRM), and (4) pseudo multiple reaction monitoring (PMRM). This study quantifies the relative performance of these methods.
Novel experiments were designed to measure the signal-to-noise (S/N) ratios of all four methods. This was accomplished by spiking the crude oil with five deuterated PAHs (dPAHs) in two distinct ways: (1) varying the background noise by changing crude oil concentrations before spiking the samples with 1 ng/mL of dPAHs, and (2) varying the signal by spiking dPAHs concentrations of 0.5 and 5 ng/mL into a crude oil sample.
The MRM method is the most selective and sensitive of the four methods. It also provides the lowest limit of detection (LOD) and limit of quantitation (LOQ). MRM is the optimal approach for quantifying PAHs in complex petroleum samples containing high levels of background noise. Also, our data show that the PAHs in complex oil spill samples can be quantified by MRM without using any complicated sample preparation steps.
Based on our experimental data, the relative performance of the four methods used for quantifying PAHs in crude oil samples can be ranked as MRM > PMRM > SIM > SCAN.
采用气相色谱/质谱联用仪（GC/MS）和气相色谱/串联质谱联用仪（GC/MS/MS），通过四种不同的方法分析油样中的多环芳烃（PAHs）：（1）全扫描（SCAN），（2）选择离子监测（SIM），（3）多反应监测（MRM），和（4）伪多反应监测（PMRM）。本研究定量评估了这些方法的相对性能。
设计了新的实验来测量这四种方法的信噪比（S/N）比值。这是通过两种不同的方式向原油中添加五种氘代多环芳烃（dPAHs）来实现的：（1）通过在向样品中添加 1ng/mL 的 dPAHs 之前改变原油浓度来改变背景噪声，（2）通过向原油样品中添加 0.5 和 5ng/mL 的 dPAHs 来改变信号。
MRM 方法是四种方法中最具选择性和最灵敏的方法。它还提供了最低的检测限（LOD）和定量限（LOQ）。MRM 是定量分析含有高水平背景噪声的复杂石油样品中 PAHs 的最佳方法。此外，我们的数据表明，无需使用任何复杂的样品制备步骤，也可以通过 MRM 定量分析复杂的溢油样品中的 PAHs。
根据我们的实验数据，用于定量分析原油样品中 PAHs 的四种方法的相对性能可以排列为 MRM>PMRM>SIM>SCAN。
