Biomedical Engineering Reference
In-Depth Information
Selected for Extraction
1400000
1200000
1000000
800000
600000
400000
200000
0
Fig. 3
Amoeba sample screening preparation of Guanfacine. Three extraction techniques (PPE,
SLE, and SPE) and twenty-six different conditions were tested simultaneously
extraction. Because there is high recovery under MCX A/B condition but no recov-
ery under MCX A/N condition, it suggested that mechanism of guanfacine using
MCX plate is true ion exchange mechanism and 100 % organic solvent under neu-
tral condition can be used for the second wash solvent to provide much cleaner
extracts. Although SLE provided the highest recovery, in order to achieve the target
LLOQ at 50.0 pg/mL, MCX extraction was ultimately selected due to large sample
volume required.
3
Chromatography Development
Method development for mass spectrometry portion of LC-MS/MS assay is rela-
tively simple and straightforward. For an experienced method development (MD)
scientist, the optimization typically takes only hours to complete. In contrast,
method development for optimal liquid chromatography conditions can be one
of the most challenging tasks. Chromatography development can be very time-
consuming. The task is further complicated by the nearly infinite choices in chro-
matography options such as vendor, sorbent, solvent selection, particle size, and
column dimensions.
