Department of Chemistry, 4000 Central Florida Blvd, Physical Sciences Room 255, University of Central Florida, Orlando, FL 32816-2366, USA.
J Chromatogr A. 2011 Sep 28;1218(39):6922-9. doi: 10.1016/j.chroma.2011.08.015. Epub 2011 Aug 16.
We present an accurate method for the determination of isomers of high-molecular weight polycyclic aromatic hydrocarbons co-eluted in HPLC fractions. The feasibility of this approach is demonstrated with two isomers of molecular weight 302 with identical mass fragmentation patterns, namely dibenzo[a,i]pyrene and naphtho[2,3-a]pyrene. Qualitative and quantitative analysis is carried out via laser-excited time-resolved Shpol'skii spectroscopy at liquid helium temperature. Unambiguous identification of co-eluted isomers is based on their characteristic 4.2 K line-narrowed spectra in n-octane as well as their fluorescence lifetimes. Pre-concentration of HPLC fractions prior to spectroscopic analysis is performed with the aid of gold nanoparticles via an environmentally friendly procedure. In addition to the two co-eluted isomers, the analytical figures of merit of the entire procedure were evaluated with dibenzo[a,l]pyrene, dibenzo[a,h]pyrene and dibenzo[a,e]pyrene. The analytical recoveries from drinking water samples varied between 98.2±5.5 (dibenzo[a,l]pyrene) and 102.7±3.2% (dibenzo[a,i]pyrene). The limits of detection ranged from 51.1 ng L(-1) (naphtho[2,3-a]pyrene) to 154 ng L(-1) (dibenzo[a,e]pyrene). The excellent analytical figures of merit associated to its HPLC compatibility makes this approach an attractive alternative for the analysis of co-eluted isomers with identical mass spectra.
我们提出了一种准确测定 HPLC 馏分中共同洗脱的高分子量多环芳烃异构体的方法。该方法的可行性通过两种分子量为 302 的异构体来证明，即二苯并[a,i]芘和萘并[2,3-a]芘。通过在液氦温度下进行激光激发时间分辨 Shpol'skii 光谱法进行定性和定量分析。共同洗脱异构体的明确识别基于它们在正辛烷中的特征 4.2 K 线宽谱以及它们的荧光寿命。在进行光谱分析之前，通过环境友好的方法使用金纳米粒子对 HPLC 馏分进行预浓缩。除了两种共同洗脱的异构体外，还评估了整个过程的分析特性，包括二苯并[a,l]芘、二苯并[a,h]芘和二苯并[a,e]芘。从饮用水样品中的分析回收率在 98.2±5.5%（二苯并[a,l]芘）至 102.7±3.2%（二苯并[a,i]芘）之间变化。检测限范围从 51.1 ng L(-1)（萘并[2,3-a]芘）到 154 ng L(-1)（二苯并[a,e]芘）。其出色的分析特性与 HPLC 的兼容性使其成为分析具有相同质谱的共同洗脱异构体的一种有吸引力的替代方法。
