激光诱导纳秒时间分辨荧光法原位测定吸附于红树叶片表面的菲

实现吸附于植物叶片表面多环芳烃(Polycyclic aromatic hydrocarbons,PAHs)的现场原位测定,是该研究领域的发展方向之一。本实验利用激光诱导纳秒时间分辨荧光(Laser-induced nanosecond time-resolved fluorescence,LITRF)系统,建立了原位测定吸附于秋茄(Kandelia obovata,Ko)、木榄(Bruguiera gymnorhiza,Bg)和桐花树(Aegiceras corniculatum,Ac)3种红树叶片表面菲(Phenanthrene,Phe)的新方法。本方法测定吸附于Ko、Bg和Ac叶片表面Phe的线性范围分别为2~1400 ng/spot,1~1000 ng/spot和4~2000 ng/spot,检测限分别为0.20,0.14和0.42 ng/spot,加标回收率为89.6%~108.1%,78.2%~92.4%和93.2%~112.9%,且方法的相对标准偏差小于6.0%(n=9)。将方法用于实验室暴露样品的原位测定,并与光纤荧光法对比,其灵敏度、线性范围改善显著,更有利于实现植物叶片上PAHs的现场原位测定。

In situ Determination of Phenanthrene Adsorbed onto Surface of Mangrove Leaves Using a Laser-Induced Nanosecond Time-Resolved Fluorescence System

To further achieve the field detection of PAHs in actual leaf samples, it is important to develop novel methods for in situ determination of polycyclic aromatic hydrocarbons (PAHs) in plant leaves. Normally, phenanthrene (Phe) is adsorbed onto the leaf surfaces of three kinds of mangrove species, named Kandelia obovata (Ko), Bruguiera gymnorhiza (Bg) and Aegiceras corniculatum (Ac). A set of laser-induced nanosecond time-resolved fluorescence (LITRF) system was utilized for the in situ quantitative detection of the absorbed phenanthrene (Phe) Experimental results showed that the linear dynamic ranges for the in situ determination of the Phe adsorbed onto the leaf surfaces of Ko, Bg and Ac were 2–1400 ng/spot, 1–1000 ng/spot and 4–2000 ng/spot, with the detection limits of 0.20, 0.14 and 0.42 ng/spot, respectively. The relative standard deviations were less than 6.0% (n = 9). The experimental recoveries for the Ko, Bg, and Ac were 89.6%–108.1%, 78.2%–92.4% and 93.2%–112.9%, respectively. Satisfactory results were obtained for the in situ determination of the Phe adsorbed onto the surfaces of the lab-exposure mangrove leaf samples contaminated by the Phe. The sensitivity of the established method was much higher than that of the previously established fiber optical fluorimetry, and the linear dynamic range got improved. The LITRF method marked a significant step towards to realizing the field detection of PAHs adsorbed onto the mangrove leaves.