碲化镉量子点用于基质辅助激光解吸电离飞行时间质谱分析全氟化合物

Cadmium Telluride Quantum Dots as Matrix for MALDI-TOF-MS Analysis of Perfluorinated Compounds

考察了CdTe量子点作为新型无机基质,应用于基质辅助激光解吸电离飞行时间质谱(MALDI-TOFMS)法分析全氟辛烷磺酸(PFOS),全氟癸烷磺酸(PFDS),全氟己烷磺酸(PFHx S)和全氟庚烷磺酸(PFHp S)4种全氟化合物(PFCs)的效果;同时与传统有机基质α-氰基-4-羟基桂皮酸(CHCA)、1,8-双二甲氨基萘(DMAN)进行比较。实验中,分别将目标分析物与基质溶液滴于样品板上并混合均匀,待自然蒸干溶剂后形成结晶状,采用337 nm波长紫外激光辐照激发,在负离子模式条件下MALDI-TOF-MS分析检测。此外,简要探讨了CdTe量子点颗粒激光辅助解吸离子化的机理。结果表明,Cd Te量子点颗粒,具有较强紫外吸收,可直接作为无机基质用于以上4种全氟化合物的MALDI-TOF-MS分析,并且具有提高待测物质谱峰强度等特点。

Cadmium telluride quantum dots （CdTe QDs） as a novel inorganic matrix were applied in matrix assisted laser desorption ionization time-of-flight mass spectrometric （MALDI-TOF-MS） analysis of perfluorinated compounds including perfluorooctane sulfonate （PFOS）, perfluorodecane sulfonate （PFDS）, perfluorohexane sulfonate （PFHxS） and perfluoroheptane sulfonate （PFHpS）, and its performance was investigated and compared with conventional organic matrix involving ct-cyano-4-hydroxycinnamic acid （CHCA） and 1,8-bis （dimethylamino） naphthalene （DMAN） under the same mass spectrometric conditions. In the experiment, the analytes and matrix were mixed on the sample plate. The crystal of analyte and matrix was excited by using 337-nm laser after the solvent was evaporated, and was detected under negative ion mode of MALDI-TOF-MS. The results demonstrated that CdTe QDs with high UV absorption could be an efficient inorganic matrix for enhancement of peak intensity in MALDI-TOF-MS analysis of perfluorinated compounds. Additionally, mechanism of ionization process was briefly discussed.