High-Speed, High-Resolution Analysis of Components in Foods Using a Nexera X2 Ultra High Performance Liquid Chromatograph

What was the background, motivation, and key selection criteria for purchasing the Nexera X2 ultra high performance liquid chromatograph for food analysis?

Well, we needed an LC system able to achieve high resolution. Because our samples come from nature, they contain large amounts of contaminant components, in addition to the principal components. Therefore, we need to separate the principal components with high reproducibility. For example, in some cases, we need to separate a specific component from 1000 other components contained in the sample. Consequently, the most important criteria were high sensitivity and high resolution.

The ability to analyze samples with high resolution is more important than that with ultra-high speed. Is that right?

Yes, we use an ultra-high-speed resolution column with an analysis time of about 15 to 20 minutes and then try to determine the analytical conditions that maximize resolution. Consequently, our analysis is not ultrafast, but the ability to reduce the analysis time from one hour using a regular HPLC system to less than half the time using the Nexera X2 is a huge benefit.

I suppose that approach also provides higher resolution, doesn't it?

Yes. Of course, reducing the analysis time is important. Given the rapid pace of changes in the food industry, we often have only a week or two available to establish methods for everything from pretreatment of new ingredients to analysis. That's why we need a UHPLC system that can evaluate a large number of analytical conditions within as short a time as possible.
UHPLC systems tend to have a reputation for only being suitable for experts. However, due to the high basic performance of the Nexera X2, I think it is well suited to even inexperienced operators. That's because it simultaneously offers both high speed and high reproducibility.

For what types of work do you use the Shimadzu HPLC system?

To start, we use it in raw material development and product development work. That involves quantitatively analyzing indicator components contained in the raw ingredients of food products and evaluating variations in components after processing the raw ingredients. We also use the HPLC system to evaluate whether or not the quantity of active ingredients decreased after conversion to a powder or drug product and for dissolution testing of drug products. Then there is also absorption testing. Absorption tests evaluate the quantity of active ingredients absorbed by the body and the changes in that quantity over time. Furthermore, we use the HPLC system for quality control, to evaluate the stability of components in accelerated testing.

In actual practice, what types of samples do you typically analyze?

Typically, we analyze bee products, such as royal jelly, propolis, honey, and bee pollen, or compounds with low or high molecular weight contained in general food ingredients.
In terms of the form of samples, we test liquid ingredients, freeze-dried and other powdered ingredients, soft and hard capsule formulations, drink formulations, and so on.

What is your impression of the Nexera X2 system after using it in actual operations?

As anticipated, it has allowed us to perform high-speed analysis with high resolution.
We can now obtain chromatograms comparable to those from existing HPLC systems in one fourth the time. We use it for about 3000 to 4000 injections per year, including for method scouting and routine analysis.
Due to the high reproducibility, we have been obtaining very reliable analytical results. Day-to-day differences in retention times and quantitation values from quantitative analysis have been within 1 %. This has been especially beneficial for gel permeation chromatography (GPC) analysis, where a 0.01 minute retention time difference can have a major effect on molecular weight. Consequently, we are able to prepare reports with confidence.
In addition, the baseline is very stable, especially for analysis at high wavelengths. We also often analyze pigments; the Nexera X2 provides a more stable baseline and higher sensitivity in the 400 to 800 nm wavelength range than LC products from other companies. The difference from competing products is especially apparent during absorption testing, when sensitivity is particularly crucial.
The large column oven accommodates a wide range of column sizes, heats up quickly, and maintains very stable temperatures.

So you say that columns are easy to install and that the oven provides a sense of security that columns won't leak during analysis?

Yes. Though a wrench is used to tighten column connections, it is easy to do once you get the hang of it. Also, there is no worry of leakage, which is especially helpful for gradient analysis. That's because, even if a column does not leak when installed, columns are prone to leak when the pressure increases during gradient analysis. If you fail to notice the leakage, then you end up having to repeat the analysis.

The Nexera X2 uses only about a third of the solvent used by regular LC systems. We appreciate the reduction in cost and trouble that has resulted from purchasing solvents and preparing mobile phases less often. That is also important in terms of protecting the environment.

If you use the system daily, as you say, then product robustness is also important, isn't it? 

For our company, which must perform a wide variety of analyses, from analyzing raw ingredients for foods to absorption testing, we operate our LC systems every single day. Given our situation, losing even one day of analysis due to a breakdown or repair is the one thing we want to avoid the most. Therefore, product robustness is extremely important.
When we were considering whether to purchase the Nexera X2 system, the distributor strongly recommended it. Also, the feedback from other sites with the Nexera X2 was that it does not break down and that service support is excellent. Another big factor was that our Shimadzu Prominence system has not failed in over ten years.

What do you think about the service support we have provided since you purchased the system?

We feel the support from Shimadzu has been good. We also felt the explanation of maintenance requirements when the system was installed was easy to understand. We were able to understand how to check functionality after replacing parts, such as checking the gradient and reproducibility using a standard sample (caffeine). With competing products, a representative only explained how to replace parts, and an actual sample was not used to check functionality. Also, Shimadzu has responded quickly to any problems by coming the same day, which is very reassuring.

Do you have any comments or requests regarding the Nexera X2 that you'd like to share?

We do not need faster speed or higher pressure capacity than it currently has. In fact, many people that have used both existing and ultra-fast LC models feel that analysis would be preferable at an intermediate point on the time axis. The Nexera X2 offers good broad applicability as a UHPLC system able to perform analysis at either high or low speeds and either high or low pressures.
In terms of our requests for the product, we would prefer that the system had a pH resistance up to pH 12. In actual practice, it is extremely rare for us to use highly alkaline mobile phases, but it would be nice if the system could be rinsed with an alkaline solution after protein-based analysis.
We also wish you would develop a column with a good S/N ratio, and we want a column that retains water-soluble components, such as organic acids and amino acids.
Column performance is still important for obtaining beautiful chromatograms with clearly separated target components. I am hoping Shimadzu will develop a resolution column based on the ghost trap technology they recommended.

Do you have any particular expectations for Shimadzu products?

We expect using the Shimadzu GC-MS system will allow us to expand our options for analysis. We would like to use the system for identifying unknown components and analyzing lipophilic components, once acquired. We also want to analyze metabolites using the system.

Thank you for providing your valuable time with us today.