H3O+, NO+和O+·2离子同九种烷氧基醇化合物反应的研究

摘要

在用选择离子流动管质谱(SIFT-MS)分析常用指甲油清洗垫发现大量4-丁酸内脂(γ-butyrolactone, GBL)和2-丁氧基乙醇(2-butoxy-1-ethanol)等挥发性气体后, 运用选择离子流动管(SIFT)对H3O+, NO+和O+·2离子同九种烷氧基醇化合物(R1-O-R2OH)之间的反应进行了研究. 获得了这些反应在潮湿空气条件下进行的情况, 并运用产物离子水合物的种类和分布来确认产物离子的结构和反应机理. 还研究了在不同载气压力下进行的反应. 结果表明, 这些化合物同H3O+和NO+的反应都是先生成初生态离子-分子络合物, (H3O+.M)*和(NO+.M)*, 然后经不同反应渠道生成各种离子产物. 这些初生态络合物同反应体系中存在的气体分子(如氦气, 氮气和氧气分子)的碰撞对最终离子产物的形成和分布也有影响. 这些化合物同O2+·反应会生成各种离解碎片离子, 但不能确定这些离子是否经由初生态络合物(O2+·.M)*生成. 该项研究提供了用SIFT-MS在空气和潮湿气体中分析这些化合物所需的反应速率常数和离子产物等动力学数据, 并将进一步应用到药物成瘾及滥用和呼吸道疾病的诊断和分析等领域.%Following a selected ion flow tube mass spectrometry(SIFT-MS), analysis of the headspace of a commercial available nail polish remover pad in which γ-butyrolactone (GBL) and 2-butoxy-1-ethanol were found to be the major volatiles, a study of the reactions of H3O+, NO+ and O+·2 ions with nine alkoxy alcohols (R1-O-R2OH) was carried out using selected ion flow tube(SIFT) at a carrier gas (helium) pressure of 9.3×101 Pa. Experiments were also performed at various carrier gas pressures (4×101-1.1×102 Pa) for some reactions and under moist air condition. The number and distribution of the hydrates for the product ions were used to identify their structures and to investigate reaction mechanisms. The H3O+ reactions proceed via nascent ion-molecule complex (H3O+.M)*, then produce R1-O-R2OH.H+, (R1-O-R2)+, HOR2OH.H+ and R2O.H+ ions through various channels. Similarly, via a nascent complex (NO+.M)*, NO+.M, (M-H)+ and (M-ROH)+ ions were produced in the NO+ reactions. The collisions between the nascent complexes (H3O+.M)* and (NO+.M)* with a third body (He, N2 and O2 etc) have influence on the product ion distributions. The O+·2 reactions produce mainly dissociative product ions and it is uncertain whether they proceed via the nascent ion-molecule complex (O+·2.M)*. This study provides rate coefficients and product ions in the SIFT-MS database for the analysis of these compounds in normal and humid air samples. It will be further utilised into addiction and drug abuse, respiratory medicine and other research areas using SIFT-MS.