Technical data

Agilent 1290 Infinity LC System Manual and Quick Reference 53

Optimization of the Agilent 1290 Infinity LC System

How to Achieve High Throughput

Some laboratories operate in a high throughput (HT) environment where the

workload requires sequences of hundreds or even thousands of injections to

be made to complete a body of work. In these situations it is highly desirable to

minimize the cycle times as even a few seconds saved per injection will reduce

the overall time to complete the work by a significant and useful amount. The

key steps to achieving fast cycle times and high throughput operation are:

• Using fast separations

• Overlapping injections

• Minimizing equilibration time

• Alternating column regeneration

The first step to achieving high throughput operation is to ensure that the

methods used have short cycle times, i.e., they are fast chromatography

methods. The use of short columns with 1.8 µm particle size packing is ideal

for this purpose because of the high efficiency available in a short column. If

the methods involve isocratic separation this allows for the fastest cycle times

because no column equilibration is required between runs. However, most

often gradient methods are employed due to the range or complexity of the

samples. In developing the method the gradient range should be kept to the

minimum required to achieve the separation. In many “open access” systems

gradients running from 5 % to 95 % organic solvent are used for the greatest

flexibility to deal with a range of unknown compounds. In the high throughput

situation it should be considered whether a shorter range will suffice on the

basis that the expected range of compounds for analysis is reduced and this

will not only allow the run time to be reduced but will also shorten the

equilibration time between runs.

The cycle time is made up of a number of parts: Cycle time = injection +

separation + equilibration + data processing.

With a large number of samples to process even a small reduction in cycle time

can add up to a large reduction in the overall time to complete the work. For

this reason the data processing can be taken off-line to allow the system to

focus on running the samples and collecting data.