With today’s analytical and contract labs under pressure to enhance productivity and minimize downtime, it may no longer be enough to base a purchasing decision on the product features and capabilities alone. Knowing that your analytical instruments will need to operate reliably day after day, consideration must be given as to how they can work to minimize the cost of operation.
Cost of Ownership and Lab Productivity
Three factors that contribute to total cost of ownership are the process, product, and productivity. The productivity factor is often overlooked because it is the most difficult to measure and quantify. It is also the most important factor of the three as it determines how well products (e.g., instruments and equipment) are being managed with respect to the process.
There are different approaches for quantifying productivity. One approach is to establish a benchmark that allows a comparison with industry averages. Another approach is to consider the product features and capabilities that may directly provide labor and resource cost savings.
Lab Productivity and Eluent Generation (EG). What is it and how does it work?
An example of feature-based cost savings is eluent generation (EG) used in ion chromatography (IC). EG electrolytically produces high purity eluents for anion and cation exchange chromatography.
Figure 1 illustrates how anion exchange eluent generation operates. It starts with a stream of high purity DI water being pumped into the KOH eluent generator. A pair of electrodes is positioned on either end of the cartridge with an ion exchange membrane separating them. When a current is applied to the electrodes, electrolysis of water generates hydroxide at the cathode. The ion exchange membrane prevents the species from recombining into water, and allows a counter-ion from the Eluent Generation Cartridge to migrate across the membrane to combine with hydroxide ions and form the KOH. The eluent concentration is varied by changing the applied current to the electrodes; making the eluent concentration variable throughout a single IC run and ideally suited for gradient separations.
What are the benefits of EG?
The benefits of EG include the following;
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- Increased sensitivity using hydroxide eluents which can be fully suppressed to water
- Improved run-to-run, week-to-week method reproducibility
- Eliminates manual preparation error
- Enables longer lasting pumps because they encounter DI water only
- Compatibility with isocratic and gradient separations
What are the cost savings of EG?
To estimate productivity cost savings, Thermo Scientific developed an IC/SP (sample preparation) on-line cost of ownership calculator. Figure 2 provides a depiction of Thermo Scientifics Cost Saving Calculator’s menu with results comparing automated on-line EG with manual eluent preparation. The example parameters, which can be easily modified to your own situation, include the following:
- EG cartridge price of $1000
- Flow rate of 0.25 mL/min (typical for a microbore 2 x 250 mm column)
- Labor rate of $40/hour
Results show a cost savings of $784 per year for EG. For more details behind the workings of the cost saving estimate, an Assumptions Tab includes a list of any additional assumptions and equations used in the calculations.
What other cost savings features are available?
While the example centers on EG for IC only, the Cost of Savings Calculator also considers columns, suppressors, as well as warranty.
In addition, the program provides the capability to factor in cost savings for Solid Phase (liquid – liquid) Extraction, Sample Preparation (solid – liquid extraction) and Filtration (syringe, in-line, and caps). Combining products, components, and service provides a more complete estimate on total cost savings.
After deciding on a particular analytical instrument based on the features, specs, and capabilities that satisfy your application needs, be sure to ask if that is enough. You may want to consider additional attributes such as robustness and cost of ownership. Because at the end of the day, your analytical instrument should be working with you and not against you.
To learn more about EG and our other cost of ownership calculators such as GC and Virtuoso vial identification systems, please click on the following links: