Simultaneous determination of pancuronium, vecuronium and their related compounds using LC-ESI-MS.

A simultaneous determination method of quaternary amino steroidal muscle relaxants, pancuronium (PAN), vecuronium (VEC), and 17-monodesacetyl pancuronium (17-OH-PAN), 3,17-bisdesacetyl pancuronium (3,17-OH-PAN), 3-monodesacetyl vecuronium (3-OH-VEC), 3,17-bisdesacetyl vecuronium (3,17-OH-VEC) in human serum was developed using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). The weak cation exchange cartridge was useful for the extraction of these compounds. Under optimized LC-ESI-MS conditions, these compounds were almost fully separated within 6.5 min. Linear responses over the concentration range 0.25-50.0 ng/mL were demonstrated for each compound. The developed method successfully detected VEC, 3-OH-VEC and 3,17-OH-VEC in serum intravenously administered with VEC. The level of 3-OH-VEC was higher than other compounds. This suggested that 3-OH-VEC was useful as a forensic probe in VEC administration.