Simultaneous determination of beclomethasone, beclomethasone monopropionate and beclomethasone dipropionate in biological fluids using a particle beam interface for combining liquid chromatography with negative-ion chemical ionization mass spectrometry.
A new simple and sensitive assay has been developed for the simultaneous quantitative measurement of beclomethasone dipropionate and its hydrolysis products in human plasma and urine. Beclomethasone 17.21-dipropionate, beclomethasone 17-monopropionate, beclomethasone and the internal standard, dexamethasone 21-acetate, were measured by combined liquid chromatography and negative-ion chemical ionization mass spectrometry with methane as the reagent gas. A particle beam interface from Hewlett Packard was used. Under mild operating conditions, abundant and stable characteristic high-mass ions were generated in the ion source of the mass spectrometer by a resonance electron-capture mechanism. The fast extraction procedure requires 1 ml of plasma or urine, and the quantification limit of the method is 1 ng ml-1 for the three tested compounds.
Girault
J
J
CEMAF s.a., Poitiers, France.
Istin
B
B
Malgouyat
J M
JM
Brisson
A M
AM
Fourtillan
J B
JB
D000328:Adult; D001507:Beclomethasone / Q000031:analogs & derivatives* / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D011786:Quality Control
C065857:beclomethasone 17-monopropionate; D001507:Beclomethasone