tag:blogger.com,1999:blog-9209375845415652006.post3796201274680028935..comments2024-01-24T09:56:18.495-05:00Comments on HPLC CHROMATOGRAPHY HINTS and TIPS FOR CHROMATOGRAPHERS [HPLC TRAINING ARTICLES] : PEAK PURITY Determination by HPLC Diode Array Chromatography Software (UV/VIS): Limitations and UsesHPLC EXPERThttp://www.blogger.com/profile/04810178046245936465noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-9209375845415652006.post-89103703464199425962017-01-27T12:15:21.659-05:002017-01-27T12:15:21.659-05:00One of the most fundamental guidelines of chromato...One of the most fundamental guidelines of chromatography is to have reproducible retention times. You indicate that your sample elutes at different retention times during the method. This indicates that your method is not reproducible. You should not use a special feature or tool such as 'Peak Purity' unless you have excellent, reproducible results. This should be demonstrated statistically by making several runs and calculating the results. Your results are only as good as the method you use. You must first improve the method. <br /><br />Here is a link to an article, "HPLC Retention Time Drift, Change, Variability or Poor Reproducibility. Common Reasons for it" which may help you troubleshoot the reason for the variation in retention time [http://hplctips.blogspot.com/2015/11/hplc-retention-time-drift-change.html]HPLC EXPERThttps://www.blogger.com/profile/04810178046245936465noreply@blogger.comtag:blogger.com,1999:blog-9209375845415652006.post-15984701626760153832017-01-27T12:07:29.987-05:002017-01-27T12:07:29.987-05:00We are getting different purity values for the sam...We are getting different purity values for the same sample using the same method. Our retention times also change for each run. 12.1 minutes, then 12.9 minutes and later each time. The earlest one had the highest purity. What are possible reasons for this?Anonymousnoreply@blogger.com