The “official minimum shelf-life” per column is 10 kits. However, most column vendors expect a minimum average shelf-life of 1,500 injections per column. This is between 5 – 10 kits. Each column may last for at least 10 kits but even after 5 – 7 kit runs a new column may be required. For calculating the required number of columns, consider the following example:

Due to the shelf-life range of columns, when running between 6 – 20 kits at least one spare column should be included in the calculations.