基于31P-NMR技术循环冷却水系统污垢中有机磷提取方法研究

Extraction method of organophosphorus from fouling of circulating cooling water system based on 31P-NMR technology

循环冷却水系统内污垢中有机磷组分的准确定性定量分析是系统调控药效的重要基础。液相磷谱核磁共振(31P-NMR)由于高灵敏度、高精度和对样品的低破坏性,逐渐被用于水环境中磷分析。建立有效的污垢中有机磷提取方法对成功利用31P-NMR进行测试至关重要。以有机磷提取量为评价指标,对提取剂种类、提取时间及提取垢量进行优化。结果表明,当提取垢量为0.4 g,提取剂为0.25 mol/L NaOH+0.05 mol/L EDTA溶液,体积为25 mL,提取时间为20 h时,颗粒态有机磷提取效果最好,其质量浓度可达26.60 mg/L;提取物的31P-NMR结果中m(磷酸单酯+正磷酸盐)∶m(膦酸盐)约为4∶1,与原配水有机磷比例一致。所建提取方法准确,提取效果好,且操作简便,为31P-NMR精准分析循环冷却水系统中颗粒态有机磷奠定了基础。

Accurate determination and quantitative analysis on organophophorus components in fouling of circulating cooling water system are important foundations for corrosion and scaling controlling.Due to the high sensitivity,high accuracy and low destrctiveness to samples,liquid-phase phosphorus spectrum nuclear magnetic resonance(31P-NMR)has gradually been used for phosphorus analysis in water environment.Establishing an effective method for organophosphorus extraction from fouling is critical to get successful result of 31P-NMR.Taking extraction quantity of organophosphorus as evaluation indexes,the types of extractants,extraction time and amount of extraction fouling were optimized.The results showed that,when the amount of extraction flouling was 0.4 g,the extractant was 25 mL 0.25 mol/L NaOH+0.05 mol/L EDTA solution,the extraction time was 20 h,the extraction effect on organophosphorus granule was the best,the mass concentration of it reached 26.60 mg/L.The ratio of m(phosphonic acid monoester+orthophosphate):m(phosphonate)was about 4:1 in the 31P-NMR results of the extract, which was consistent with the ratio of organophosphorus in the original simulated water. It showed that, the said extraction method was accurate, the extraction effect was excellent, and the operation was simple, which laid foundation for the accurate analysis of organophosphorus in fouling of circulating cooling water system by 31P-NMR.