Ion-pair liquid chromatography–electrospray mass spectrometry for the analysis of cyclic nucleotides

Bacterial phospholipid molecular species analysis by ion-pair reversed-phase HPLC/ESI/MS

“…The results were that TBABr did not significantly degrade the phospholipid standard responses until the counter-ion concentration, into phase C, was less than 40 mM. Beyond this limit, as previously reported by Witters et al (29), both a pollution of the electrospray source and a progressive loss of sensitivity after several runs were observed. Furthermore, instead of using TBABr, tetrabutyl ammonium acetate (TBAAc) was used.…”

“…We observed a poor separation of the phospholipid classes, and we were not able to distinguish the different molecular species. Abidi and Mounts (9) studied different tetraalkyl ammonium ho- (28,29). They showed that both the nature of the alkyl chains and the concentration of the ion-pairing reagent could increase the retention and the separation of several molecular species of PE or PC.…”

“…Thus, since tetraalkyl ammonium homologs were never used for HPLC/ESI/MS analysis of phospholipids as far as we know, we investigated an efficient counter-ion. We chose first the TBABr that was previously used for HPLC/ESI/MS analysis of cyclic nucleotides (29) and studied the effects of this ion-pairing reagent on phospholipid detection. Subsequently, we considered a dichloromethane-methanol-water (25:60:15, v/v) mobile phase supplemented with TBABr.…”

Development of generic liquid chromatography-mass spectrometry methods using experimental design

“…The use of many of these additives have generally been ruled out when liquid chromatography is coupled to a mass spectrometer because of the nonvolatility of the additives, resulting in suppression of ionization. However, some nonvolatile salts have been successfully used for IP-LC-MS. Cetyltrimethylammonium chloride has been used for the analysis of N-nitrosoamino acids [7] and low concentrations (50 -500 mM) of tetrabutylammonium bromide has been used for the analysis of cyclic nucleotides [8]. A solution to the compatibility issue has been to use more volatile amines, such as dimethylhexylamine, which has been used in the analysis of a metabolite of clodronate [9].…”

Cyclic Nucleotides and Nucleotide Cyclases in Plant Stress Responses

“…This study exploited the use of polyclonal antibodies raised in chicken against an adenosine 3',5' monophosphate-diphtheria toxoid antigen construct in developing an immunoaffinity purification procedure to measure cAMP and hence AC activity. Technological advances providing an even better reproducibility of quantitative data brought the detection limit of cyclic nucleotides down to 25 fmoles in plant extracts by combining liquid chromatography and electrospray ionization (ESI) mass spectrometry Witters et al, 1997;Witters et al, 1999). Due to the high sensitivity of ESI, it has become the technique of choice for the analysis of polar biomolecules.…”