HPLC (High Performance Liquid Chromatography), GC (Gas Chromatography), and TLC (Thin Layer Chromatography) are a tandem of powerful analytical tool used to solve almost all separation activities in the laboratory.
In our first blog article on increasing the sensitivity in case of limit of detection (LOD) / limit of quantitation (LOQ) problems in HPLC methods, we addressed the increase in sensitivity primarily by reducing baseline noise. Now we will look on the same topic from another perspective – with the eyes of “method optimization”. What can be optimized to increase the peak size and thus the overall signal to noise ratio (S/R)?
During validation of purity testing methods of drugs or their active ingredients, sooner or later a point comes when the detection and quantification limits are needed to be determined. The limit of detection or LOD is defined as the lowest amount of an analyte in a sample that can still be detected. This is different from quantification - since the limit of quantitation (LOQ) is the lowest amount of an analyte in a sample that can still be reliably quantified.
HPLC methods are often part of routine analysis of drugs or drug substances in pharmaceutical QC laboratories under GMP conditions.
The shape of the peak of a HPLC chromatogram is extremely critical for its evaluation. Subtle changes in the shape during a quantitative measurement can lead to misleading results and in turn can ruin the entire measurements obtained throughout the experiment. Therefore, it is important to keep a watchful eye on the “peak shape”.