I am looking for a procedure (reference) for the cleaning of glassware used in the analysis of nitrosamines by LC-MS/MS. Considering that using detergents with LC-MS/MS isn’t a good idea. I will be very grateful for any insights on this.
This is my practice - in active use, glad to share, but not to be used as a standard!
Avoid Contaminants:
As a first step, clean all glassware using general detergents at high heat and water pressure when contamination is severe
Then, avoid general detergents during regular cleaning.
Do not use HPLC-grade solvents (e.g., water, MeOH, MeCN).
Water Selection:
Evaluate and test water sources, especially those labelled LC-MS-grade water.
MilliQ water may not be sufficiently clean; assess multiple vendors for optimal purity.
Pipette Tips:
Evaluate different brands and rinse pipette tips to minimize among other things, phthalates contamination.
Use the best water from an evaluated source for rinsing.
Occasional Heavy Cleaning:
Periodically clean all glassware using general detergents at high heat and water pressure when contamination is severe.
Ensure the drying process is fast and done at a high temperature.
Pre-Use Rinsing:
After heavy cleaning, thoroughly rinse glassware with clean water or methanol (that will be used during the analysis), in other words as a second step, hand wash/rinse.
Drying:
Air dry the rinsed glassware in a functioning fume hood, ensuring minimal handling to prevent recontamination.
Caution: not all gloves used in the lab are safe for nitrosamines’ analysis. Data shows gloves can be a source for nitrosamines too. [William J. Gee, 2023]