NACE‐ESI‐MS combined with on‐line concentration for high‐sensitivity analysis of quinolizidine alkaloids

Abstract

A rapid, reproducible and high-sensitivity NACE-ESI-MS method was developed for the analysis of sophoridine, matrine, sophocarpine and oxymatrine in the roots of Sophora flavescens Ait. and S. tonkinensis Gagnep. Field-amplified sample stacking with electromigration-injection (FASS-EMI) was first used in NACE for the on-line concentration of the alkaloids. The conditions of NACE separation, FASS-EMI stacking and MS detection were systematically optimized. The optimum NACE buffer was an electrolyte containing 50 mM ammonium acetate, 0.5% acetic acid and 30% ACN in methanol. The sensitivity was improved by about 100-fold by the FASS-EMI technique, which was further improved by more than 1000-fold with MS detection. The RSDs (n = 6) of the relative migration time and relative peak area of each peak were less than 0.3 and 2.4% for intra-day and less than 5.1 and 6.0% for inter-day, respectively. The LODs (S/N = 3) of analytes were determined to be 0.0210-0.0446 ng/mL. A bioanalytical method based on this NACE-ESI-MS method may be developed for the analysis of the alkaloids in biological sample matrices (plasma, urine, etc.) after effective ion removal.

Quality control of herbal medicines by capillary electrophoresis: Potential, requirements and applications

“…By using an acidic phosphate buffer at pH 2.5, which contained 1% HP-X-CD and 3.3% isopropanol, and an internal standard (scopolamine butylbromide), the accurate quantitative determination of all major alkaloids in plant material was feasible in 15 min. In other reports the separation of four quinolizidine alkaloids (sophocarpine, sophoridine, matrine and oxymatrine) in an alkaline (60 mM borate at pH 8.5; [23]) buffer or by NACE is described [24]. The non-aqueous buffer contained 50 mM ammonium acetate, 0.5% acetic acid and 30% ACN in methanol; for analysis samples were injected by applying 26 kV for 20 s. By using this field applied samples stacking procedure a 100-fold increase in sensitivity was noticed compared with regular hydrodynamic injection.…”

Nonaqueous CE ESI‐IT‐MS analysis of Amaryllidaceae alkaloids

“…When CE is coupled to MS via an ESI interface, SL is usually used to ensure the electrical connection of CE outlet and MS and a stable electrospray . The SL can affect the analytes transferring from the liquid phase into the gas phase.…”

A Non-Biological Method for Screening Active Components against Influenza Virus from Traditional Chinese Medicine by Coupling a LC Column with Oseltamivir Molecularly Imprinted Polymers

“…Their chemical structures and oxides are shown in Figure 1. The contents of these two alkaloids are much more than those of other stereoisomers in Sophorae Flavescentis Radix [37]. …”