Rapid on-line extraction and quantification of escitalopram from urine using sol-gel columns and mass spectrometric detection.
A fast and easy way to quantify escitalopram in urine has been developed. A capillary with a silica based monolithic bed inside is used to extract escitalopram from urine and the for mass spectrometry detrimental matrix is washed away by applied pressure. The analyte is eluted by a solution containing organic modifier and directly electrosprayed into a time-of-flight mass spectrometer, ESI-TOF-MS. This method makes it possible to load large volumes of sample onto the column and preconcentrate escitalopram on-line before detection. Standard addition of escitalopram to the urine sample gave a linear calibration curve (R(2)=0.988). The analyzed sample was found to contain an escitalopram concentration of 0.62 ng/ml, well in line with earlier publications. The calculated LOD was 10 pg/ml and LOQ was 34 pg/ml as compared to earlier reports with a LLOQ of 1 ng/ml. The intra day variation of the escitalopram peak area is less than 6.3%.
Johannesson
Nina
N
Analytical Chemistry, Department of Physical and Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden.
Bergquist
Jonas
J
D000928:Antidepressive Agents / Q000652:urine*; D002138:Calibration; D053801:Capillary Electrochromatography; D015283:Citalopram / Q000652:urine*; D006801:Humans; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D012015:Reference Standards; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization
D000928:Antidepressive Agents; D007202:Indicators and Reagents; D012996:Solutions; D015283:Citalopram