Rapid determination of water-soluble B group vitamins in urine by gradient LC/MS with a disposable home-made microcolumn

摘要

A rapid and simple analytical method without pretreatment, based on gradient LC/MS with a disposable microcolumn, has been developed to determine B group vitamins in urine. Urine samples were directly injected to the disposable home-made microcolumn. A 5 cm silica capillary with a sintered silica frit was placed in the microcolumn outlet. A 1/32 inch coupling union with graphite Vespel ferrules was used to give a safe and void volume free connection between the 5 cm capillary and a long capillary to the electrospray interface. The microcolumn can be emptied after being used for a series of urine samples, and repacked with fresh stationary phase. Healthy volunteers swallowed an overdose of vitamin pills, and the urine samples were collected 1,2,3,5, and 8 hours after swallowing. Vitamins immediately showed up in urine, hit the maximum, and disappeared swiftly. This technique is expected to have some application for clinical purposes.