Low bleed columns are essential for the integrity of analytical results. The amplitude of baseline noise associated with column bleed is indicative of stationary phase stability. A low bleed, stable column produces consistent results, and the low baseline noise enables improved limits of detection with enhanced resolution of low level analytes. Column bleed also contributes to contamination of the MS; minimizing column bleed extends the interval between scheduled maintenance, leading to higher productivity. This test focuses on the high temperature range close to the operating limits of the columns used, where column bleed is most observable. Columns are held at 325°C for 5 minutes and then the temperature is ramped to 350°C were it is held for another 5 minutes. It can be seen from Figure 1 that the TraceGOLD TG-5MS GC column offers the lowest column bleed of the five columns tested, particularly at the higher temperature of 350°C.