UMR-CNRS 6521, University of Bretagne Occidentale, 6 Av. Le Gorgeu, BP 809, 29285 Brest Cedex, France.
Talanta. 2003 Jun 13;60(2-3):295-302. doi: 10.1016/S0039-9140(03)00102-4.
This paper presents a synthesis of some analytical potentialities of an equipment designed for both laser induced molecular and atomic fluorescence in the field of ultra-trace analysis (ng l(-1)). Excitation of fluorescence was performed with a pulsed Nd:Yag laser coupled to an optical parametric oscillator (OPO). Fluorescence spectra were recorded with a spectrograph and an intensified charge-coupled device (ICCD). The high energy and the tunability of the excitation combined with the sensitivity of the ICCD and the time-resolution provide better limit of detection (LOD) and selectivity. By molecular fluorescence, some major organic contaminants in the environment were studied, i.e. polycyclic aromatic hydrocarbons (PAHs) (benzo[a]pyrene and hydroxypyrene) and a pesticide (carbaryl). The LODs achieved by direct analysis were far below the restricted European values for tap water. Analysis was performed in water containing humic acids using time resolution to avoid the matrix fluorescence. By electro thermal atomisation-laser excited atomic fluorescence (ETA-LEAF), we detected traces of aluminium and lead in seawater. Some general considerations about the signal to noise ratio optimisation are reported. LODs reached the femtogram level.
本文综合介绍了一种专为痕量分析（ng l(-1)）领域中的激光诱导分子和原子荧光而设计的设备的一些分析潜力。荧光激发采用脉冲 Nd:Yag 激光与光学参量振荡器（OPO）相结合的方式进行。荧光光谱由光谱仪和增强型电荷耦合器件（ICCD）记录。高能量和可调谐性的激发结合 ICCD 的灵敏度和时间分辨率，提供了更好的检测限（LOD）和选择性。通过分子荧光，研究了环境中的一些主要有机污染物，如多环芳烃（PAHs）（苯并[a]芘和羟基芘）和一种农药（carbaryl）。直接分析的检测限远低于自来水中的限制欧洲值。在含有腐殖酸的水中进行分析时，采用时间分辨来避免基质荧光。通过电热原子化-激光激发原子荧光（ETA-LEAF），我们检测到海水中痕量的铝和铅。本文还报告了一些关于信噪比优化的一般性考虑。检测限达到了飞克级水平。
