Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6.
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6.
Anal Chim Acta. 2014 Jan 15;808:115-23. doi: 10.1016/j.aca.2013.07.039. Epub 2013 Jul 26.
The relative degree of fluorotelomer-based acrylate polymers (FTACPs) fluorination was demonstrated to influence the sample preparation protocol for matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry. A homologous series of FTACPs were synthesized from fluorotelomer and hydrocarbon acrylates of different chain lengths, which varied the ratio of perfluorinated to hydrogenated carbons (RF/RH). The solubility of FTACPs in tetrahydrofuran (THF) and chloroform was observed to decrease for highly fluorinated FTACPs (RF/RH>0.5) promoting FTACP aggregation. No dependence on the degree of fluorination was observed for the solubility of FTACPs in the fluorinated solvents α,α,α-trifluorotoluene (TFT) or dichloropentafluoropropanes (HCFC-225). For FTACPs with a low degree of fluorination such as poly(8:2 FTAC-co-HDA) (RF/RH=0.375), MALDI-ToF analysis was successful using a conventional sample preparation protocol with THF, and dithranol (Dith) matrix. Conversely, the poor solubility of the highly fluorinated poly(8:2 FTAC-co-BA) (RF/RH=1.5) in THF resulted in mass discrimination. Several fluorinated sample preparation protocols were evaluated for poly(8:2 FTAC-co-BA) using TFT and HCFC-225, and decafluoroazobenzene (DFAB) or 2-[(2E)-3-(4-tert-butylphenyl)-2-methylprop-2-enylidene]malononitrile (DCTB) matrices. The high volatility of HCFC-225 decreased FTACP pooling during solvent evaporation in comparison to the less volatile TFT, and improved the quantity of detectable signals. MALDI-ToF analysis of poly(8:2 FTAC-co-BA) in a 95:5 HCFC-225:methanol with DCTB being the best sample preparation protocol for highly fluorinated FTACPs in this study producing the highest number of observable signals. Employing a fluorinated sample preparation offers the capability of analyzing other highly fluorinated polymers that are not compatible with conventional sample preparations.
基于氟端基丙烯酸酯聚合物（FTACPs）的氟化程度会影响基质辅助激光解吸/电离飞行时间（MALDI-ToF）质谱分析的样品制备方案。本研究合成了一系列不同链长的氟端基和碳氢丙烯酸酯的 FTACPs，改变了全氟化碳与氢化碳的比例（RF/RH）。发现高度氟化的 FTACPs（RF/RH>0.5）在四氢呋喃（THF）和氯仿中的溶解度降低，促进了 FTACP 聚集。在氟化溶剂α,α,α-三氟甲苯（TFT）或二氯五氟丙烷（HCFC-225）中，FTACPs 的溶解度与氟化程度无关。对于低氟化程度的 FTACPs，如聚（8:2FTAC-co-HDA）（RF/RH=0.375），使用 THF 和间苯二酚（Dith）基质的常规样品制备方案可以成功进行 MALDI-ToF 分析。相反，高度氟化的聚（8:2FTAC-co-BA）（RF/RH=1.5）在 THF 中的溶解度较差导致了质量歧视。本研究还评估了几种氟化样品制备方案，用于使用 TFT 和 HCFC-225 以及十氟偶氮苯（DFAB）或 2-[(2E)-3-(4-叔丁基苯基）-2-甲基丙烯-2-亚基]丙二腈（DCTB）基质的聚（8:2FTAC-co-BA）。与挥发性较低的 TFT 相比，HCFC-225 的高挥发性降低了 FTACP 在溶剂蒸发过程中的聚集，从而提高了可检测信号的数量。使用 DCTB 的 95:5 HCFC-225:甲醇作为最佳样品制备方案，对聚（8:2FTAC-co-BA）进行 MALDI-ToF 分析，这是本研究中针对高度氟化的 FTACPs 的最佳样品制备方案，产生了最多数量的可观察信号。采用氟化样品制备方法可以分析与常规样品制备方法不兼容的其他高度氟化聚合物。
