柱前衍生-固相萃取-高效液相色谱荧光测定生物脱氮反应器中痕量信号分子AI-2

为揭示污水生物脱氮工艺中污泥菌群间的群体感应作用，建立了柱前衍生-固相萃取-高效液相色谱荧光检测法(HPLC-FLD)定量检测介导细菌种间群体感应信号分子AI-2的方法。取反应器的泥水混合液，经0.45 μm滤膜过滤后，用氨基磺酸掩蔽亚硝酸盐干扰，并与2,3-二氨基萘(DAN)发生衍生化反应，衍生化产物用C18固相萃取柱进行固相萃取，经氮吹浓缩后上机分析。采用C18色谱柱(4.6 mm×250 mm，5 μm)进行分离，乙腈与水(含0.1%甲酸)作为流动相进行梯度洗脱，使用荧光检测器(激发和发射波长分别为271 nm和503 nm)进行检测。结果表明，该检测方法在1~200 ng·mL-1范围内呈现出了良好的线性关系，检出限为1 ng·mL-1，回收率为55.08%~59.25%，相对标准误差为2.98%~10.41%。该方法适用于杂质干扰多的痕量信号分子AI-2 定量分析，可为生物脱氮工艺中信号分子AI-2介导群体感应研究提供有效的分析方法。

Detection of AI-2 signal molecules of quorum sensing in biological nitrogen removal processes by pre-column derivatization-solid phase extraction-high performance liquid chromatography with fluorescence detector

To reveal the mechanism of quorum sensing in biological nitrogen removal processes, a method using pre-column derivatization, solid-phase extraction and high-performance liquid chromatography with fluorescence detector (HPLC-FLD) was established for quantitation of AI-2 signal molecules. The samples collected from the reactor and filtered through 0.45 μm filter membrane, then were reacted with amino-sulfonic acid to mask nitrite and derived with 2,3-diaminonaphthalene(DAN). The derived products were extracted and concentrated by solid phase extraction (SPE), and then determined by HPLC (C18 column, 4.6 mm×250 mm, 5 μm) with fluorescence detector (excitation wavelength and emission wavelength were 271 nm and 503 nm, respectively). Gradient elution was carried out by acetonitrile and water (containing 0.1% formic acid) as mobile phases. The results presented an excellent linearity with the concentration ranging from 1 to 200 ng·mL-1, and the detection limits were 1 ng·mL-1. The recovery ratio of sample ranged from 55.08% to 59.25%, with the relative standard deviations of 2.98% to 10.41%, respectively. This method provided an effective analytical method for quantitation of trace signal molecule AI-2 in biological nitrogen removal processes.