液相色谱-电喷雾串联质谱法测定人尿中三聚氰胺和三聚氰酸

Hydrophilic interaction liquid chromatography coupled with electrospray tandem mass spectrometry for the analysis of melamine and cyanuric acid residues in urine

目的建立人尿中三聚氰胺和三聚氰酸的亲水作用液相色谱-电喷雾串联质谱法,对门诊病人尿液中三聚氰胺和三聚氰酸进行调查。方法样品加入同位素内标后采用亲水性键合硅胶和阳离子交换树脂复合填料固相萃取小柱(MCT)浓缩净化,甲醇和5%氨水甲醇溶液两次洗脱,收集流出液,用氮气吹干,用1 ml乙腈+2 mmol/L乙酸铵(90+10)充分溶解后,亲水作用色谱柱分离,采用电喷雾串联四极杆质谱进行检测。结果在2.0μg/L^1000.0μg/L时,三聚氰胺和三聚氰酸线性关系良好(相关系数r分别为0.9998和0.9997)。在50.0 ng/L、200.0 ng/L和5000 ng/L 3个添加水平范围内的平均回收率为97.8%~100.1%,相对标准偏差小于4.02%,方法检出限为三聚氰胺4.0 ng/L、三聚氰酸3.0 ng/L。结论采用建立的方法测定了尿中三聚氰胺和三聚氰酸,结果表明,该法快速、准确、灵敏,优于现有分析方法。

Objective To establish a sensitive method for the simultaneous determination of melamine and cyanuric acid residue in urine by hydrophilic interaction liquid chromatography coupled with electrospray tandem mass spectrometry. Methods The melamine and cyanuric acid in urine were cleaned - up by a mixed mode solid phase extraction column （MCT） of hydrophilic functional silica gel sorbent and cation exchange resin, then detected by high performance liquid chromatography - tandem mass spectrometry. Identification was achieved by positive - negative switched electrospray ionization mode using multiple reaction monitoring. Quantification was performed by internal standard calibration. Results The melamine and cyanuric acid were linear in the range of 2.0 μg/L - 1000 μg/L with correlation coefficient of 0. 9998 and 0.9997. The detection limits of the method were 4.0 ng/L （melamine） and 3.0 ng/L （cyanuric acid） in urine, respectively . The recoveries at three levels ranged from 97.8% to 100.1% （ n = 7 ）. And the relative standard derivations were lower than 4.02%. Conclusion The method was sensitive, accurate and precise, which could meet the requirements of monitoring and control of the environmental pollution about the melamine and eyanuric acid in urine.