Improving the performance of narrow-bore HPLC columns using active flow technology

Active flow technology (AFT) columns are designed to remove inefficient flow processes associated with the column wall and radial heterogeneity. This study is the first to explore AFT on a 2.1 mm internal diameter (i.d.) column, emulating a 1.0 mm i.d. column. The performance of the AFT column was compared to a conventional 1.0 mm i.d. column; at the highest linear velocities tested it was observed that the AFT column functioning as a virtual 1.0 mm i.d. column had an efficiency gain that was 58% compared to the conventional 1 mm i.d. column. The performance of the AFT column was also compared to a conventional column of the same physical dimensions and smaller particles; at the highest velocity tested for the conventional 3 μm column, the AFT virtual 1.0 mm i.d. column had a 20% efficiency with half of the backpressure. These comparative gains in efficiency at high flow rates demonstrate the advantage of using AFT 2.1 mm i.d. columns with a virtual 1 mm i.d., for high throughput analyses and low volume detection methods; additionally, a sensitivity gain of 45% was observed.