Kauppila T J, Nikkola T, Ketola R A, Kostiainen R
Division of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Helsinki, FIN-00014 Helsinki, Finland.
J Mass Spectrom. 2006 Jun;41(6):781-9. doi: 10.1002/jms.1034.
A group of five neurotransmitters with different properties was analyzed using atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization-mass spectrometry (APCI-MS). The sensitivity of the techniques for the analytes was tested in six solvents and in positive and negative ion modes. APPI was found to be superior in sensitivity for all the compounds in both positive and negative ion modes. In positive ion mode, water/methanol/formic acid was found to be the best solvent, whereas in negative ion mode, water/methanol/ammonium hydroxide performed best. Detection limits using APPI were between 2.5-250 fmol, depending on the compound. The sensitivity was best for the neurosteroids dehydroepiandrosterone and beta-estradiol, and acetylcholine (LOD 2.5-10 fmol).
使用大气压光电离（APPI）和大气压化学电离质谱（APCI-MS）对一组具有不同性质的五种神经递质进行了分析。在六种溶剂以及正离子和负离子模式下测试了这些技术对分析物的灵敏度。结果发现，APPI在正离子和负离子模式下对所有化合物的灵敏度都更高。在正离子模式下，水/甲醇/甲酸被发现是最佳溶剂，而在负离子模式下，水/甲醇/氢氧化铵的效果最佳。使用APPI的检测限在2.5-250飞摩尔之间，具体取决于化合物。对神经甾体脱氢表雄酮、β-雌二醇和乙酰胆碱的灵敏度最高（检测限为2.5-10飞摩尔）。
