Electrospray mass spectrometry of phosphoramidites, a group of acid-labile compounds

Template-directed formation of luminescent lanthanide complexes: Versatile tools for colorimetric identification of single nucleotide polymorphism

“…Elemental analysis was performed on a CHN Corder MT-6 (Yanaco). ESI-TOF/MS (electrospray ionization-time of flight mass spectrometry) measurements of activated esters were carried out using an acetonitrile solution saturated with lithium chloride and analyzed using a LCT spectrometer (Micromass) in positive ion mode [43]. DNs were purchased from Hokkaido System Science Co., Ltd (Japan), or synthesized on an Oligo1000M (Beckman) or Expedite 8900 (Applied Biosystems) DNA synthesizer with dimethoxytrityl phosphoramidite reagents purchased from Glen Research (USA).…”

Electrospray Ionization Mass Spectrometric Analysis of Highly Reactive Glycosyl Halides

“…Based on our earlier experience [12], anhydrous acetonitrile was selected as a solvent because it is frequently used in carbohydrate chemistry, compatible with the ESI-MS instruments, the protected glycosyl halides are highly soluble in it, and it can dissolve the required amount of adduct-forming lithium salt.…”

“…Based on our earlier experience with sensitive phosphoramidites [12,13], we started our experiments with lithium chloride as an adduct-forming agent. However, we also examined the cases without adduct-forming ions, with formic acid (used in routine ESI cocktails) and other salts (LiF, LiBr, LiI, LiNO 3 , LiClO 4 , NaCl, NaNO 3 , NaClO 4 , KCl, KNO 3 , KClO 4 , NH 4 Cl, NH 4 NO 3 , NH 4 HCO 3 , NH 4 OOCH, NH 4 OOCCH 3 ) in order to investigate the formation of positive and negative ions and the influence of anions.…”

“…All mass spectrometric measurements were performed on a Waters Q-TOF Premier spectrometer (Waters, Milford, MA, USA) equipped with a built-in nanoelectrospray ion source [12]. A high voltage of ca.…”

“…Our previous experience in the nanoelectrospray mass spectrometric investigation of similarly acid- and nucleophile-sensitive phosphoramidites employing lithium chloride adduct ions [12] spurred us to consider the application of our method to selected glycosyl chlorides and bromides. In a later development we have been able to extend the scope of our lithium chloride method to the high resolution MS characterization of phosphoramidites [13], thus the accurate mass determination allowed us to confirm the elemental composition of analytes.…”