2-Aminoethylphosphonic acid (2-AEP) and 2-amino-3-phosphonopropionic acid (2-AP3) are two types of abundant and ubiquitous naturally occurring phosphonates used as sources of phosphorus by many prokaryotic lineages. The potential utilization mechanism of 2-AEP and 2-AP3 in eukaryotic phytoplankton is currently under investigation. However, the lack of suitable analytical methods in saline samples are the limitation of such researches. Herein, a high-performance liquid chromatography (HPLC) method for monitoring 2-AEP and 2-AP3 using precolumn fluorescence derivatization with o-phthalaldehyde-ethanethiol (OPA-ET) in seawater matrix was developed. The derivatization procedure and HPLC conditions were carefully examined, which included optimization of the fluorescence excitation and emission wavelengths, the ammonium acetate concentration and pH of the mobile phase, the OPA-ET reagent content and composition and derivatization time. Because increasing salinity was observed to lower the derivatization efficiency, working standards were freshly prepared in artificial seawater with the same salinity as that of the samples for the quantification of 2-AEP and 2-AP3. The developed HPLC method showed a wide linear response with high linearity (R² > 0.999) and high repeatability at three concentration levels. The relative standard deviation was less than 4.1% for 2-AEP and less than 1.7% for 2-AP3 (n = 7). The limits of detection for 2-AEP and 2-AP3 in artificial seawater matrix were both 12.0 μg/L. The recoveries were 83.0–104% for 2-AEP and 72.6–98.6% for 2-AP3 in different aqueous samples, including algal culture medium prepared with filtered seawater. These results indicated the matrix effect of this method was insignificant.

2-氨基乙基膦酸（2-AEP）和2-氨基-3-膦酸丙酸（2-AP3）是两种丰富而普遍存在的天然膦酸酯，被许多原核生物谱系用作磷源。目前正在研究2-AEP和2-AP3在真核浮游植物中的潜在利用机制。但是，盐溶液中缺乏合适的分析方法是此类研究的局限性。本文介绍了一种高效液相色谱（HPLC）方法，该方法使用预柱荧光衍生化或邻苯二甲酰胺监测2-AEP和2-AP3开发了海水基质中的邻苯二甲酰乙硫醇（OPA-ET）。仔细检查了衍生化过程和HPLC条件，包括优化了荧光激发和发射波长，流动相的乙酸铵浓度和pH，OPA-ET试剂含量和组成以及衍生化时间。由于观察到盐度升高会降低衍生化效率，因此在人工海水中新鲜制备了工作浓度与用于2-AEP和2-AP3定量的样品相同的盐度的工作标准液。发达的HPLC方法显示出宽线性响应和高线性（R ² > 0.999）和在三个浓度水平下的高重复性。2-AEP的相对标准偏差小于4.1％，2-AP3的相对标准偏差小于1.7％（n = 7）。人工海水基质中2-AEP和2-AP3的检出限均为12.0μg/ L。在不同的水样中，包括用过滤过的海水制备的藻类培养基，2-AEP的回收率为83.0–104％，2-AP3的回收率为72.6–98.6％。这些结果表明该方法的基质作用不明显。