液相色谱-质谱法直接进样测定水中丙烯酰胺的基质效应

Research on the Matrix Effect in Direct-Injection Liquid Chromatography-Mass Spectrometric Determination of Acrylamide in Water

采用柱后注射法和前处理后添加法评定高效液相色谱-串联质谱法（LC-MS-MS）的基质效应,研究了不同色谱条件对水样丙烯酰胺测定中基质效应的影响,提供了有效削减基质效应的方法,并建立了直接进样测定水中丙烯酰胺的LC-MS-MS法。研究表明,流动相溶剂强度、添加剂种类及浓度对LC-MS-MS直接进样测定水中丙烯酰胺的基质效应影响显著;通过调节流动相溶剂强度和甲酸高度使丙烯酰胺保留时间与基质效应出现的时间段错开,可避开基质效应;在10%甲醇-90%水流动相中添加0.01%～0.02%甲酸可显著降低基质效应,对水中丙烯酰胺的检出限为0.03μg/L,对自来水、地表水、地下水的加标回收率为96.7%～105%,相对标准偏差为1.7%～6.4%。建立的LC-MS-MS直接进样法简便、快速、灵敏度高、定性定量准确可靠,适合水中丙烯酰胺的超痕量分析。

An optimized direct-injection high performance liquid chromatography-tandem mass spectrometry （LC-MS-MS） method by diminishing the matrix effect has been developed for detection of acrylamide in water. The influence of different chromatographic conditions on the matrix effect was investigated with the post-column infusion method and the addition-after- pretreatment method. The results indicated that chromatographic conditions such as the solvent intensity of mobile phase and content of the additive in mobile phase had dramatic effects on the matrix effect. The matrix effect could be eliminated by adjusting mobile phase ratio and the species and formic acid content to separate the acrylamide peak from matrix peaks, such as with a mobile phase consisting of 10% methanol and 90% water containing 0.01% -0.02% formic acid. The detection limit of the optimized direct-injection LC-MS-MS method was 0. 03 μg/L. The reeoveris and relative standard deviations were 96.7% - 105% and 1.7%-6.4% respectively for acrylamide in real water samples including tap water, sufaee water and groundwater. This method is simple, rapid, sensitive and accurate for ultra-trace analysis of aerylamide in water.