Supelco's new Low Adsorption (LA) vials are manufactured using a process that decreases the number of hydroxyl groups on the vial's glass surface, significantly reducing surface activity while improving analytical quantitation and minimizing pH shifts in the sample. This same process also removes unwanted surface metals such as sodium and boron that can contaminate samples and interfere with trace analysis. Unlike other methods used to decrease vial surface activity, the elimination of surface activity in LA vials is integral to the manufacturing process and is not a chemical surface treatment.These vials and closures are designed, engineered, and manufactured for optimum performance in HPLC, GC/MS, and LC/MS applications. All of the parts of the vial system (vial, cap, and septum) can come into contact with the sample and are critical to the outcome of the analysis. We recommend using LA vials with MSQ polypropylene cap/PTFE silicone septa. This cap and septa combination was purposely designed for use with mass spectrometry. It shows little to no background contamination when compared to other cap and septa products in the marketplace.