Solvent front position extraction procedure with thin-layer chromatography as a mode of multicomponent sample preparation for quantitative analysis by instrumental technique

Solvent front position extraction with semi-automatic device as a powerful sample preparation procedure to quantitatitation of tryptophan in human plasma

“…SFPE procedure optimization. As it was presented in our previous papers [30][31][32]35 the precision and accuracy of the SFPE technique are based on the premise that both sample components and the internal standard after chromatogram developments were evenly distributed in the focused common zone of the final solvent front position. The obtaining of the final solvent front position was preceded by additional chromatogram development which allowed cleaning the sample solution from matrix components showing weaker and stronger retention than the solutes of interest.…”

“…Before chromatogram development the plates were washed in methanol for 1 min. Next, the plates were dried in the air and activated in an oven at 105–110 ◦ C for 15 min 31 – 33 , 35 .…”

“…F = 3000 mm/min, the efficiency of the mobile phase solution delivery to the adsorbent layer: 6 mL/h. The last stage brought the substance zones to a common place in the solvent front position 30 , 31 , 35 .…”

“…In our previous papers we proposed the modern approach to sample preparation procedure, especially for biological samples 30 – 32 . The procedure is named as the Solvent Front Position Extraction (SFPE) 31 and is based on the following steps 30 – 32 : (a) the internal standard (IS) is added to the sample, (b) a drop of the sample solution is applied on the chromatographic plate, (c) the chromatogram is developed to locate the substance/s of interest and internal standard/s zones at the final solvent front position, (d) the substance/s and internal standard are extracted from this zone (or its part) and transferred to the instrumental device for quantitation. The procedure was tested, with very satisfactory results, for preparation of samples of serum matrix, which was fortified with the solute of interest (acetaminophen) and internal standard (acetanilide) 30 .…”

“…The procedure was tested, with very satisfactory results, for preparation of samples of serum matrix, which was fortified with the solute of interest (acetaminophen) and internal standard (acetanilide) 30 . Next, the analogous procedure was tested to a more complex sample containing 8 substances characterized by different properties 31 . By finding the appropriate chromatographic system during screening tests and overcoming the problem of the radial chromatography at the stage of application of the sample, all substances of interest were successfully determined with an error of less than 5% 33 .…”