Metrohm has introduced the Metrosep A Supp 16 range of high-capacity anion exchange columns with an inner diameter of 2mm for clinical, pharmaceutical, toxicological and environmental samples.
The microbore columns are said to offer better mass sensitivity, less eluent consumption, smaller sample amounts, better hyphenation and less impact on the environment.
Assuming identical sample amounts, microbore-based separations show a better mass sensitivity (peak heights and peak areas) than standard bore separations.
Changing from a 4mm to a 2mm inner diameter column will reduce eluent consumption to about a quarter.
This is said to be highly favourable for the operation of ion chromatographs in nuclear power plants that run round the clock and where incoming and outgoing goods pass laborious inspections and should therefore be minimised.
Small-diameter columns provide an increased absolute mass sensitivity and are mainly used for clinical, pharmaceutical, toxicological and environmental samples with limited sample amounts.
By reducing the column diameter to half, a four-fold decrease in column volume and therefore a lower flow rate is achieved.
The challenge in coupling IC to MS consists in adjusting the generally higher column flow rate to the required flow rate for the ion source of the MS.
Due to their reduced flow rate, microbore columns can be directly interfaced with online electrospray mass spectrometers.
Reduced eluent consumption and smaller amounts of samples required mean that microbore-based IC leaves a smaller environmental footprint.