HPLC has made significant contributions in detection and quantitative estimation of organic compounds. In pharmaceutical analysis HPLC has been extensively used in assay of the active ingredient as well as related impurities which are present in formulations in very low concentrations. Estimation of related substances was not possible using other conventional analysis techniques. This unique ability of HPLC has been successfully exploited for validation of glassware cleaning before it can be put to use for making sensitive analytical determinations.
It is clear that glassware should be cleaned to your complete satisfaction so that you are confident of the results communicated by you. In case you lack confidence then you should be prepared for criticisms on your reports. Cleaning of laboratory glassware suggests cleaning practices for different types of glassware based on the analysis requirements.
Next the question will arise if you can rely on adequacy of your cleaning or further cleaning would be necessary. In other words cleaned glassware will require validation for cleanliness before use. Cleaning validation is a set of practices laid down to ensure the effectiveness and consistency of the cleaning method for removal of residues from earlier analysis, contaminants or even from the detergents used for cleaning. US FDA prescribed screening requirements under GMP through the standard 21 CFR 211.67 covering manufacture and testing of drugs. Click here to See the link.
Laboratory glassware cleaning involves repetitive rinses with deionised water or an organic solvent followed by drying in hot air oven. It is important to use water or solvent of high purity grade so that it does not contribute to the contamination of the glassware. During analysis using sophisticated analytical techniques such as HPLC you can come across a set of peaks (referred to as ghost peaks) whose presence cannot be explained. The first thing that can come to your mind could be that such peaks result from impurities present in available standards, blank solutions, reagents or even unclean samples. Such sources of contamination can be investigated independently but due consideration should be given to inadequate cleaning of the glassware before putting it to use.
The residues remaining after cleaning and levels of detergents used in the cleaning process or trace impurities present in de-ionized water or organic solvents necessitates use of a sensitive analytical technique. HPLC is a good choice as it offers a large number of possibilities due to selection from a range of columns and detectors. Generally HPLC systems with a UV detector, photodiode array detector and a C-18 column in reverse phase mode is adequate for the purpose. HPLC offers high sensitivity and detection limits besides providing advanced automation features that can contribute to large scale studies on cleanliness validation of volumetric glassware items as per requirements mandated by the standard.