On-line pretreatment using methylcellulose-immobilized cation-exchange restricted access media for direct liquid chromatography/mass spectrometric determination of basic drugs in plasma.
A novel methylcellulose-immobilized restricted access media column with strong cation-exchange groups on an internal surface (MC-SCX) was evaluated for the direct injection analysis of basic polar drugs in plasma by column-switching liquid chromatography/mass spectrometry (LC/MS). Analytical conditions, including an automated pretreatment step and MS detection, were optimized for a series of basic drugs (doxepin, desipramine, imipramine, nortriptyline, amitriptyline, clomipramine). On-line pretreatment with the MC-SCX column followed by fast gradient analysis using a C18 column resulted in a total analysis cycle time of 7 min for each spiked plasma sample. More than 150 plasma samples spiked with target compounds were measured without compromising MS detection (relative standard deviations less than 11% for all compounds, and regression coefficients greater than 0.99).
Kawano
Shin-ichi
S
Analytical Applications Department, Shimadzu Corporation, 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto 604-8511, Japan. kawashin@shimadzu.co.jp
Takahashi
Masatoshi
M
Hine
Takashi
T
Yamamoto
Eiichi
E
Asakawa
Naoki
N
D000818:Animals; D001774:Blood Chemical Analysis / Q000379:methods*; D002411:Cation Exchange Resins / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D008747:Methylcellulose / Q000737:chemistry*; D009862:Online Systems; D004364:Pharmaceutical Preparations / Q000097:blood*; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D002411:Cation Exchange Resins; D004364:Pharmaceutical Preparations; D012996:Solutions; D008747:Methylcellulose