Micro liquid chromatography—mass spectrometry with direct liquid introduction used for separation and quantitation of all-trans- and 13-cis-retinoic acids and their 4-oxo metabolites in human plasma

Retinoid quantification by HPLC/MSn

“…Sensitivity is severely decreased for other isomers, however, and reagents that are toxic to the cells cannot be used (6). Other HPLC/MS procedures (44)(45)(46) do not provide the specificity of MS n techniques. This HPLC/MS n procedure provides both quantitative measurement and a high degree of specificity for multiple retinoids.…”

A sensitive and specific method for measurement of multiple retinoids in human serum with UHPLC-MS/MS

“…A lack of analytical separation power may have confounded individual isomer detection, whereas a lack of good MS/MS sensitivity has prevented selective quantifi cation of individual retinoids. Previous methods have been developed using LC-MS/MS ( 9,(16)(17)(18)(19)(20)(21), GC/MS ( 22 ), and LC/diode array detector-atmospheric pressure chemical ionization/MS/MS ( 23 ). However, none of these methods has incorporated measurement of hydroxylated RA metabolites at endogenous levels in serum.…”

Methods for detecting and identifying retinoids in tissue

“…Historically only a handful of articles have described the use of LC-MS for the determination of retinoids in biological samples (Eckhoff et al, 1990;Fayer et al, 1991;Ranalder et al, 1993;Bempong et al, 1995). During the last decade however, modern soft atmospheric pressure ionization techniques like electrospray (ESI) and atmospheric pressure chemical ionization (APCI) have been explored for retinoid analysis.…”