Zielke Ii Brian T
Curia Wisconsin, Inc. D/B/A Siegfried Acceleration Hub, 870 Badger Circle, Grafton, WI, 53024, United States.
Heliyon. 2024 Dec 6;10(24):e41018. doi: 10.1016/j.heliyon.2024.e41018. eCollection 2024 Dec 30.
Primary and secondary alkyl iodides and primary alkyl bromides were quickly and conveniently converted into their corresponding alkyl chlorides via S2 halide-halide substitution. The resultant alkyl chlorides simultaneously demonstrated increased volatility and stability paired with standard headspace GC-FID methodology. The derivatization was performed on both standard and sample alike and occurred during the headspace oven equilibration phase, eliminating the extra reaction step traditionally performed during many derivatization analyses. Reaction times, temperatures, and completeness of conversion were studied as well as response from common headspace solvents and application of various chloride sources. Recovery of iodomethane from four challenging substrates was studied from the trace level to approximately 1000 ppm. Recovery ranged 94-110 % from verapamil hydrochloride (2.5-1007 ppm), 95-102 % from methylnaltrexone bromide (26-1054 ppm), and 92-106 % from (S)-laudanosine (49-942 ppm). Using hydrogen chloride as the chloride source, a method for determination of residual iodomethane in (S)-N-methyl-laudanosine iodide was validated over a 0.5-24.9 μg/mL range with a 0.1 μg/mL detection limit, 91-103 % accuracy, and 3.2 % relative standard deviation.
伯烷基碘、仲烷基碘和伯烷基溴可通过S2卤化物-卤化物取代反应快速便捷地转化为相应的烷基氯。所得烷基氯与标准顶空气相色谱-火焰离子化检测（GC-FID）方法同时显示出更高的挥发性和稳定性。标准品和样品均进行衍生化反应，且在顶空进样器加热平衡阶段发生，省去了许多衍生化分析中传统的额外反应步骤。研究了反应时间、温度、转化的完整性以及常见顶空溶剂的响应和各种氯化物来源的应用。研究了从四种具有挑战性的底物中痕量水平至约1000 ppm的碘甲烷回收率。盐酸维拉帕米（2.5 - 1007 ppm）的回收率为94 - 110%，甲基纳曲酮溴化物（26 - 1054 ppm）的回收率为95 - 102%，（S）-劳丹碱（49 - 942 ppm）的回收率为92 - 106%。以氯化氢作为氯化物来源，验证了一种在0.5 - 24.9 μg/mL范围内测定（S）-N-甲基-劳丹碱碘化物中残留碘甲烷的方法，检测限为0.1 μg/mL，准确度为91 - 103%，相对标准偏差为3.2%。
