Abstract An improved technique is demonstrated for the accurate collection of TO-15 compounds over 1-7 days. Constant sampling rates and good recoveries of a l l TO15 compounds are demonstrated, using very low sampling rates that could potentially result in target compound losses and carryover if exposed filters and surfaces are not properly passivated. Consistent sampling rates and analyte recoveries are demonstrated using 3 Silonite coated and 2 uncoated CS1200E5 samplers as collected into 5 different Silonite coated canisters. Sampling rates were below 1cc/min to simulate the sampling rates used for collecting one week samples into 6L canisters. Five CS1200E5 samplers were also connected to 6L canisters and allowed to sample for 1 week to demonstrate consistent target compound recovery, and consistent final fill pressures using an updated flow control design which improves consistency for 1 week sampling.