固相萃取柱上衍生气相色谱-质谱法测定水中烷基酚

以烷基酚(APs)主要降解产物辛基酚(4-t-OP)、壬基酚(4-n-NP)为研究对象,建立了固相萃取(SPE)柱上衍生化、气相色谱-质谱(GC-MS)法测定水中APs的分析方法。以C18柱为固相萃取柱、N,O-(三甲基硅)三氟乙酰胺(BSTFA)为硅烷化试剂,设计五因素四水平正交实验L16(45),对衍生化影响因素、衍生化溶剂、衍生化时间以及SPE主要影响因素pH值、盐度和洗脱剂进行优化;在优化条件下,方法的回收率(高于80%)和重现性(RSD低于10%)结果令人满意,4-t-OP和4-n-NP的仪器检出限分别为3.35ng/L和6.38ng/L。采用建立的方法,回收率略高于传统的SPE萃取衍生法,具有有机溶剂用量少,方法简单快速、灵敏度高的特点,适用于河水和海水中痕量烷基酚的快速测定。

Determination of Alkylphenols in Water by Solid-phase Extraction with on-Column Derivatization Coupled with Gas Chromatography-Mass Spectrometry

An analytical methods based on solid-phase extraction(SPE)with in situ derivatization followed by gas chromatography-mass spectrometry has been developed for the determination of alkylphenols(APs)in water samples.Two important APs,4-n-nonylphenol and 4-t-octylphenol,were selected as the target compounds for method development.The SPE extraction was conducted on a C18 extraction cartridges with on column silylation by bis(trimethylsilyl)trifluoroacetamide.Operationasl parameters including silylation reagent silylation time,pH value,concentration of salts,elulent which are expected to impact on the recoveries of analytes were optimized by orthogonal experimental design.It is shown that the acetone is the best silylation reagent while DCM was efficient in eluting APs from SPE cartridges.The recovery of APs increases slightly with increasing concnetration of NaCl in the range of 0-1.5% of NaCl,beyond the concentration of 1.5%,the recovery of APs starts to decrease.But the recovery of APs reduced by the increase in pH value.The optimised method was further verified by performing spiking experiments in ultrapure water and seawater matrices,with good recovery and reproducibility for all the selected compounds.The method showed better performance than the reported liquid liquid extraction-derivatization method in terms of analytical speed,procedural simplicity and recovery.