Agilent Technologies Using Software Tools to Improve the Detection of Impurities by LC/MShttp://www.manuallib.com/file/2652308
ManualLib.com collects and classifies the global product instrunction manuals to help users access anytime and anywhere, helping users make better use of products.
Home: http://www.manuallib.com/ Chinese: http://www.shuomingshuku.com/
This Manual: http://www.manuallib.com/file/2652308
Using Software Tools to Improve the Detection of Impurities by LC/MS
Christine MillerAgilent TechnologiesIntroduction Experimental
The analysis of raw materials and finished prod-
The analysis was performed using an Agilent 1100
ucts for minor impurities presents a challenge in
Series LC/MSD SL. A decomposed stock solution
many industries. Liquid chromatography/mass
of salbutamol sulfate (10 mg/ml) was diluted in
spectrometry (LC/MS) is often the technique of
water to 100 pg/µl and injected directly into the
choice because of its broad sample applicability,
LC/MSD. The sample was analyzed in positive
separating power, and ability to provide structural
electrospray ionization (ESI) mode. Data analysis
information. However, without advanced software
was performed using the LC/MSD ChemStation
tools, it is difficult to locate minor impurities in
the presence of chemical noise and high-levelcomponents. This application brief demonstratesthe use of the Agilent 1100 Series LC/MSD SLquadrupole mass spectrometer with ChemStationsoftware for the analysis of minor components ina partially decomposed sample of the broncho-dilator salbutamol.
This Manual: http://www.manuallib.com/file/2652308
Using Software Tools to Improve the Detection of Impurities
Results and Discussion LC/MS ANALYSIS METHOD
Figure 1A shows the total ion chromatogram (TIC)
Chromatographic Conditions
for the analysis of the decomposed salbutamol
sample. While there were hints of several peaks in
the 6.9 to 9.5 minute range, the impurities were
largely obscured in the chromatographic baseline.
A two-step ChemStation data analysis procedure
was used to extract meaningful information from
this chromatogram. The first step involved the
background subtract (BSB) routine, which sub-
tracts the selected background spectrum from
each point in the entire MS data set and saves the
results as a separate file so that the original data
MS Conditions
is always preserved. For this sample, an averaged
spectrum from near the apex of the salbutamol
peak was background subtracted resulting in
greatly enhanced visualization of the impurities
Second, the “Overlay base peak chromatogram”
(BPC) feature was used to further improve the
detection of impurities. The BPC is constructed
from the base peak abundance of each scan in theanalysis, where the base peak in a spectrum is theion with the maximum abundance. Creating theBPC of the background-subtracted data for thesalbutamol analysis revealed that there were eightor more impurities previously hidden in thechromatographic baseline (Figure 1C).
This Manual: http://www.manuallib.com/file/2652308
Using Software Tools to Improve the Detection of Impurities
A. Display TIC Possible impurities B. Subtract salbutamol spectrum from TIC C. Create base peak chromatogram from background-subtracted TIC Figure 1. Sequence of steps to extract impurity peaks from total
This Manual: http://www.manuallib.com/file/2652308
Using Software Tools to Improve the Detection of Impurities
Figure 2 shows the pseudomolecular ion for each
have been obtained by increasing the LC/MSD
chromatographic peak as well as spectra for some
fragmentor voltage to generate collision induced
of the impurities. While this analysis was suffi-
dissociation or by using the MS/MS capabilities of
cient to satisfy the immediate need, further
an Agilent 1100 Series LC/MSD Trap ion trap
structural information for the impurities could
m/z 224 m/z 461 Salbutamol m/z 238 m/z 240 m/z 210.1 m/z 282 m/z 134 m/z 226 m/z 431 m/z 238 Figure 2. Mass spectral information for salbutamol impurities
This Manual: http://www.manuallib.com/file/2652308
Using Software Tools to Improve the Detection of Impurities
Conclusions
This work demonstrates that the LC/MSD Chem-
Christine Miller is an applications chemist at
Station software is a powerful system for analysis
Agilent Technologies in Palo Alto, California
of sample impurities. The ChemStation software
provides useful tools for locating minor compo-nents previously hidden in the chromatographicbaseline. www.agilent.com/chem
Information, descriptions and specifications in this publication aresubject to change without notice. Agilent Technologies shall not be liablefor errors contained herein or for incidental or consequential damages inconnection with the furnishing, performance or use of this material.
All rights reserved. Reproduction, adaptation or translation without prior written permission is prohibited, except as allowed under thecopyright laws.
Printed in the U.S.A. August 16, 20025988-7611EN
This Manual: http://www.manuallib.com/file/2652308
NCMIR METHODS FOR 3D EM: A NEW PROTOCOL FOR PREPARATION OF BIOLOGICAL SPECIMENS FOR SERIAL BLOCK FACE SCANNING ELECTRON MICROSCOPY Thomas J. Deerinck, Eric A. Bushong, Andrea Thor and Mark H. Ellisman Center for Research in Biological Systems and the National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA Note: This protocol was desig
Feridun Zaimoglu Kiepenheuer Witsch Verlag München 2006 ISBN 3-462-03696-3 Feridun Zaimoglu Translated by Margot Bettauer Dembo That disgraced sect of troublemakers can’t get the better of me in every single competitive business deal, Halid says, They’ll come to a bad end. He loops his wavy-edged reversible silk tie around his neck and bends down to drink some wat