Page 61 - LC-SFC_Pharma_Brochure

C191-E044

(3) To Avoid Recognizing Long-Period Undulations as Peaks
[Maximum Half Width]
The maximum half width, which is the opposite of the minimum half
width, is a parameter that can be specified to ignore larger peaks as
baseline undulations. For example, Fig. 10 shows baseline drift ap- Technical A New Peak Integration Algorithm for
pearing as a large baseline bulge that could be recognized as a peak.
This undulation can be removed by specifying a maximum FWHM. Report LabSolutions

0.95 1.00 min 0.95 1.00 min
[Unify Peaks by Shoulder Ratio] Not conÿgured [Unify Peaks by Shoulder Ratio] = 0.01 (%)
Yusuke Osaka , Shinji Kanazawa , Hiroaki Kozawa , Etsuho Kamata 1
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Fig. 12 Example of Setting a Threshold for Recognizing Shoulder Peaks
4. Customizable Default Values
4. Customizable Default V alues
0.0 5.0 min 0.0 5.0 min Abstract:
[Maximum Half Width] Not conÿgured [Maximum Half Width] = 20 (sec) The i-PeakFinder parameters can be configured as the default values
Fig. 10 Example Con guration of Maximum FWHM of methods. For example, if a user decides to use vertical division as The time required to analyze large quantities of data obtained from the increasingly quick analyses and increasingly prevalent simultaneous
the peak-baseline type, specifying vertical division as the default set- multicomponent analyses in recent years has become a challenging issue. In addition, the strengthening of regulations associated with data
(4) To Unify Fused Peaks into a Single Peak ting can omit the effort involved in adjusting the parameter for each integrity has given rise to demands for automated and simpliÿed manual methods for integrating the areas of problematic chromatogram
[Unify Peaks by Separation Width] new analysis. LabSolutions is an integrated workstation capable of peaks. Herein, we introduce a new peak integration algorithm for LabSolutions, i-PeakFinder, which is designed to resolve these issues.
The minimum half width setting is used to avoid mistakenly recogniz- controlling a range of different instrument models. However, the
ing noise as peaks, while unifying peaks by separation factor is used HPLC and GC systems occasionally require different default peak in- Keywords: Data processing, peak integration, algorithm
to combine fused peaks into a single peak. Fig. 11 shows three fused tegration settings. Accordingly, default settings can be specified for
peaks. Configuring this setting will unify the two side peaks into the each type of instrument (Fig. 13).
larger peak. Note that this setting is only effective for baseline inter-
vals containing fused peak.
1. Introduction der and main peaks using traditional peak integration methods, i-Peak-
oduction
Intr
1.
Finder can automatically detect shoulder peaks while maintaining con-
i-PeakFinder, a new peak integration algorithm for LabSolutions, is a sistent peak detection sensitivity throughout the entire chromatogram.
completely automated integration function that can detect peaks with In general, it is difÿcult to automatically detect considerably small shoul-
high levels of accuracy without requiring special parameter adjust- der peaks, as shown in Fig. 2; however, i-PeakFinder can even detect
ments. In addition, this algorithm has adjustable parameters that such peaks automatically based on the threshold judgment.
allow the integration function to be applied to a wide range of com-
plex chromatogram patterns. Furthermore, the adjustable parameters
allow to output highly accurate peak integration results from large
quantities of data, even for batch analysis.
2. Features of i-PeakFinder
8.1 9.0 min 8.1 9.0 min 2. Featur es of i-PeakFinder
[Unify Peaks by Separation Width] Not conÿgured [Unify Peaks by Separation Width] = 2
With Shimadzu's traditional peak integration methods or competitor
Fig. 11 Example of Unifying Unresolved Peaks
Fig. 13 The Default Settings Window methods, some complex chromatograms require time programming in
(5) To Decide Whether to Recognize Shoulder Peaks addition to the typical parameter adjustments for peak integration.
[Unify Peaks by Shoulder Ratio] However, i-PeakFinder can perform peak integration of these chro- Highly accurate detection of shoulder peaks
5. Summary
When impurities were fused as shoulder peaks at the base of a main 5. Summary matograms just with simple parameter adjustments. This peak inte-
component peak, the traditional peak integration method required gration function has the following features:
time programming or manual peak integration to detect the shoulder i-PeakFinder, a new peak integration algorithm developed by Shi-
peak. i-PeakFinder allows easy detection of shoulder peaks and also madzu, can perform either automated peak integration or peak inte- • Highly accurate detection of shoulder peaks
allows the user to decide whether to recognize (or not) impurity peaks gration with simple settings adjustments, even for cases in which the • Simple adjustment of peak-baseline processing
based on a threshold ratio of the main component peak height to the traditional peak integration method requires time programming or • Improved peak-baseline positioning that results in improved reproducibility
shoulder peak tangential height. Fig. 12 shows an example of shoul- manual peak integration for individual data sets. i-PeakFinder also • Performing accurate peak integration even with variabilities caused
der peak detection implemented without time programming or allows the user to easily configure the peak-baseline type and per- by baseline drift
manual peak integration and an example of using the threshold value form accurate peak integration of small peaks. Peak detection at low S/N levels Automatic determination of
to unify the shoulder peak with the main component peak. Configur- Furthermore, i-PeakFinder can quickly and easily process large quanti- Shimadzu also emphasizes on compatibility, so LabSolutions can also baseline undulation and drift
ing a threshold value can also be used as a condition for deciding ties of data without errors and improve the efficacy and reliability of be used with the traditional peak integration methods (Chromatopac
whether to recognize impurity peaks. analytical operations. mode). Switching between the traditional peak integration and
i-PeakFinder methods during analysis is easy, allowing the user to
First Edition: July, 2017 select an appropriate peak integration method for the circumstances.
This includes selecting a traditional method for compatibility with
past data. Fig. 1 shows examples of using the completely automated
integration function to analyze typical peaks.
2-1. Highly Accurate Detection of Automatic tracking of peak Automatic tracking of noise
Shoulder Peaks width variation intensity changes

i-PeakFinder can accurately detect shoulder peaks. In cases wherein Fig. 1 i-PeakFinder's Completely Automated Integration Function
manual peak integration is required to distinguish and detect the shoul-

© Shimadzu Corporation, 2017 1 Analytical & Measuring Instruments Division 1