分析红树植物样品中多环芳烃时色素干扰的去除方法

A Clean up Method of Pigment Interferes for PAHs in Mangrove Plant Samples

建立了一种用于分析红树植物样品中PAHs含量的萃取液净化方法.采用微波辅助萃取法对红树植物样品中的PAHs进行萃取,将萃取液中的叶绿素皂化;再用OasisHLB反相固相萃取小柱富集PAHs,使之与叶绿素皂化产物等杂质分离,以二氯甲烷洗脱PAHs后用GC-MS测定.替代物回收率在75.2%～107.9%之间,RSD为0.5%～8.5%,检出限范围为0.17～2.35ng/g.

Hydrophilic products of chlorophylls through saponification can be removed from extracts of plant samples by Oasis HLB reversed solid-phase extraction cartridge. Based on this, an extraction and clean up method for PAHs in mangrove plant samples had been developed. After undergoing microwave assisted solvent extraction, the extracts reacted with saponifing solution （2 mol/L KOH in methanol-water,80 ： 20, by vol. ）, and a clean up of pigments was performed with Oasis HLB reversed solid-phase extraction cartridges. The pigment interferes were not remained on the cartridge and the retained PAHs were eluted with dichloromethane and determined with GC-MS. The ranges of average recovery of surrogates, RSD and method detection limit of spiked samples were found to be 75.2% to 107.9% ,0. 5% to 8.5% and 0. 17 to 2.35 ng/g,respectively. Chlorophylls and carotenoid could be eliminated to a great extent from the plant extracts for PAHs detection.