The technique used to fill a VOA vial is at least as important a source of variance in VOC analysis as is well purging protocol or sampler design. The more the sample stream is agitated or exposed to the air during the transfer of sample from the bailer to the vial, the lower the concentration detected in the vial will be.
The greatest loss of VOC's occurs when the sample is simply poured into the vial through the top of the bailer. Bottom emptying bailers with too rapid a flow also cause major losses. SingleSample® VOC Removal Devices afford a superior method for getting the sample out of the bailer and into the vial without the loss of VOC's.