Measurement of Total Organic Carbon (TOC) in ultra-pure water is required in pharmaceutical, electronics and semiconductor industries. Typically, the water sample is collected into clean glass containers and analysed directly to minimise contamination. The USP 643 procedure mentions that containers must have been scrupulously cleaned of organic residues as this could result in higher TOC values. Hence, it is critical to ensure that these glass sampling containers have low organic residues. Organic carbon residues in glass containers can be checked by gas chromatography - mass spectrometry following EPA Drinking Water Method 524.2. Organic residues can also be measured by a TOC analyzer. However, there are no international standard methods to evaluate TOC in glass containers. Here, we describe a method to measure TOC content in glass containers using Shimadzu TOC-VWP TOC analyzer. The TOC-VWP, with a detection limit of 0.5 ppb uses the wet-oxidation method which combines ultra-violet (UV) irradiation, persulfate reagents and heating at 80 °C.