Page 9 - Shimadzu Co-Sense Series

Analyzing Ultra-Trace Impurities Using Co-Sense for Impurities

Analyzing ultra-trace impurities requires both increased sensitivity and reliable separation of impurities from primary components.
Concentrating the sample or injecting large volumes of samples in an attempt to improve sensitivity can cause difficulties with
achieving both solubility and separation. However, Co-Sense for Impurities is able to achieve both increased sensitivity and reliable
separation by trapping and concentrating target impurities after large-volume injections and then separating them with second
dimension separation.

Higher Sensitivity Using Co-Sense for Impurities

Even in cases where increasing sensitivity is difficult with normal one-dimensional separation, Co-Sense for Impurities is able to
increase sensitivity by approximately 40 times by combining a semi-preparative scale for first dimension separation and ultra-fast
separation after trap concentration. This achieves high-sensitivity analysis with absorbance detection at a low operation cost.

mAU
Example of Analyzing 0.0002 % Impurities in Imipramine
4.0
In the first dimension separation, the 0.015 mAU peak was trap
concentrated and then eluted as sharp peaks using a high-speed
high-separation column. This resulted in increasing the sensitivity by
2.0
Impurity approximately 40 times to 0.56 mAU. Also, increasing the sensitivity
(trap)
resulted in a good peak area repeatability of 1.08 %RSD, even for the
ultra-trace impurity concentration of 0.0002 %.
First dimension
0.0
Second dimension
Impurity
0.0 5.0 10.0 15.0 20.0 min

Analyzing Impurities Using Co-Sense for Impurities in Combination with LC/MS

Even if a non-volatile buffer solution is used as the mobile phase for the first dimension, Co-Sense for Impurities is able to desalt the
solution by trap concentration. Consequently, it can be used in combination with LC/MS regardless of the separation conditions,
which means impurities can be analyzed in more detail by LC/MS. Using LC/MS allows analyzing MS spectra and checking the
specificity of peaks in MS chromatograms.

Example of Analyzing Impurities in Rabeprazole
<First Dimension>
Phosphate buffer solution
as mobile phase LC/MS analysis that was independent of the mobile phase conditions was
UV 290 nm
accomplished by trap concentrating and desalting impurities detected by
Impurity
(trap) separation in a phosphate buffer solution, then delivering them with an
LC/MS mobile phase to the second dimension. In addition, LC/MS allowed
detecting the peak separation that could not be adequately verified
0.0 5.0 10.0 15.0 min based on UV detection.
<Second Dimension>
Ammonium formate as
mobile phase IM1
LC/MS
394.05(+)
IM2
508.15(+)
IM3
569.25(+)

0.0 5.0 10.0 15.0 min

Co-Sense Series
High Performance Liquid Chromatograph 9