Drop Coating Deposition Raman (DCDR) for Microcystin-LR Identification and Quantitation
Drop Coating Deposition Raman (DCDR) for Microcystin-LR Identification and Quantitation
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DOI：
10.1021/es200255y
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发表时间：
2011-07-01
影响因子：
11.4
通讯作者：
Vikesland, Peter J.
中科院分区：
文献类型：
--
作者：
Halvorson, Rebecca A.;Vikesland, Peter J.
建立了一种滴涂沉积拉曼（DCDR）方法，用于分析2-200 ng样品中的微囊藻毒素- lr （MC-LR）。固相萃取（SPE）技术可以在5 μ g/L到100 mg/L的浓度范围内鉴定出MC-LR，收集的结果表明，在DCDR底物改性后，可以很容易地获得较低的检出限。DCDR工艺适用于0.5-20 μ L的水样体积，产生的样品沉积物可以在几秒钟内获得MC-LR拉曼光谱。不需要更大体积的样品来提高光谱分辨率。2 μ L的体积是理想的，产生“咖啡环”MC-LR沉积，在200 ng样品的1 s和2 ng样品的300 s内显示出明显的MC-LR拉曼信号，具有高信噪比。信号归一化后，2 ~ 100 ng MC-LR样品的拉曼信号强度与浓度呈线性相关。从新鲜和陈年样品中收集了可重复的MC-LR拉曼光谱。在3 μ g DOM和0.7 μ g MC-LR混合的DCDR沉积物中，溶解有机物（DOM）的存在并不妨碍MC-LR的鉴定。将DCDR应用于环境样品将需要在分析前进行样品纯化，如SPE，包括关键的药筒洗涤和毒素冲洗步骤。基于拉曼的方法可能有一天会比传统的MC-LR检测方法更简单、更快。
A drop coating deposition Raman (DCDR) method was developed for the analysis of 2-200 ng samples of microcystin-LR (MC-LR), a ubiquitous and deadly hepatotoxin secreted by cyanobacteria. Solid phase extraction (SPE) of the toxin from a water sample enabled identification of MC-LR at 5 mu g/L to 100 mg/L concentrations, and the collected results suggest lower detection limits can be readily attained following DCDR substrate modification. The DCDR process was applied to aqueous sample volumes of 0.5-20 mu L that generated sample deposits from which MC-LR Raman spectra could be obtained within seconds. Larger volume samples were not required to improve spectral resolution. Volumes of 2 mu L were ideal, producing "coffee-ring" MC-LR deposits that displayed distinct MC-LR Raman signals with high signal-to-noise within 1 s for a 200 ng sample and 300 s for a 2 ng sample. A linear correlation between Raman signal intensity and concentration was observed for 2-100 ng MC-LR samples after signal normalization. Reproducible MC-LR Raman spectra were collected from both fresh and aged samples. The presence of dissolved organic matter (DOM) did not preclude MC-LR identification in DCDR deposits of 3 mu g of DOM mixed with 0.7 mu g of MC-LR. Application of DCDR to environmental samples will require sample purification such as SPE before analysis, including critical cartridge wash and toxin rinsing steps. Raman based methods may one day facilitate simpler and faster sample throughput than traditional MC-LR detection methods.