超高效液相色谱-串联四极杆质谱法对N-甲基氧化吗啉及其降解产物的检测

Determination of N-Methylmorpholine-N-oxide and Its Degradation Products by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

建立了N-甲基氧化吗啉（NMMO）及其降解产物吗啉、N-甲基吗啉、N-亚硝基吗啉的超高效液相色谱-串联四极杆质谱联用的分析方法。以Waters Acquity BEH C18超高效液相色谱柱为分析柱，乙腈-氨水为梯度洗脱液，4种分析物在3min内即可达到良好分离；经串联四极杆质谱多反应监测模式检测，4种物质的线性范围为10—500μg／L，检出限为1～10μg／L。考察了酸性、碱性两种流动相体系对样品的分离效果，发现碱性流动相体系的分离效果优于酸性流动相体系，同时发现质谱响应信号随着流动相pH值的增大而减小。在优化条件下，对实际样品以及加标后样品进行测定，结果满意，该方法适合大批量Lyocell纤维纺丝凝固浴等样品的测定以及NMMO的出口检测。

A sensitive ultra performance liquid chromatography -tandem mass spectrometry（ UPLC - MS/MS） method was developed for the separation and determination of N-methylmorpholine-N-oxide （NMMO） and its main degradation products, i. e, N-nitrosomorpholine（NNM）, N-methylmorpho line（NMM） and morpholine（MOR）, in Lyocell fiber sample. The sample was effectively separated in 3 min on a Waters Acquity BEH C18 column using acetonitrile and water（ containing 0. 1% ammonia） as mobile phase under the condition of gradient elution. The detection of compound was performed by MS under multiple reaction monitoring（MRM） mode. The calibration curves were linear over the concentration range of 10 -500 μg/L for all compounds with detection limits of 1 - 10 μg,/L. The effects of mobile phase systems and pH values on separation efficiency were investigated. The resuits indicated that the separation efficiency of compounds in basic mobile phase was higher than that in acidity system, and the response of mass spectrometry was decreased with increasing pH value of mobile phase. Under the optimal conditions, the method was applied in the determination of NMMO and its degradation products in real samples and spiked samples. The validated method offers a sensitive and versatile approach to determine the level of NMMO and its main degradation products in a complex matrix of Lyocell fiber.