Working under Ultra High Pressure
Mikhail S. Tswett, a Russian Botanist used a solvent for extracting compounds from leafs in the early 19th century. For the separation of the compounds he packed open glass columns with alumina or powdered chalk particles and loaded the leaf extract on the top of the columns. Then he added pure solvent and observed a separation of the compounds according to their and the columns materials physical and chemical properties. Liquid chromatography (LC) was born. Tswett called his development chromatography from the greek words "chroma" for color and "graph" for writing. Maybe the naming was not a coincidence since Tswett is the Russian word for color.
If one simply uses gravity as driving force, the particles in the columns must be relatively large, resulting in a small surface and a poorer separation. If particle size is minimized you need a bigger force to press the solvent through the column. The Hungarian-American chemical engineer Csaba Horváth coined the acronym HPLC for using a pump to produce a force for faster and smaller particles. The pressure used in HPLC increased from 35 bar in the late 60s to 400 bar in the early 70s.
At this year's Pittcon in Orlando Shimadzu presented their new Nexera UHPLC system working with pressures up to 1,300 bar and columns with sub-2 µm particles.
G.I.T. Laboratory Journal Europe talked to Dr. Masayuki Nishimura, Senior Global Marketing Manager to find out about Shimadzus' latest technical innovation.
G.I.T. Laboratory Journal Europe: Dr. Masayuki Nishimura, Shimadzu chose a new marketing strategy for Nexera by using Pittcon and Analytica for the first official launches in the USA and Europe. Is this a signal for a more international marketing orientation of your company?
Dr. Masayuki Nishimura: In the past, both trade shows have always been important events for Shimadzu, and we have launched our new products there meeting highly specialized audiences from all over the world. This will continue in the future. Regarding our international marketing orientation: we have restructured our international marketing teams in order to better meet the needs of international players in pharmaceutical, chemical and food industry - just to mention a few.
They work pan-continental. Nevertheless, Shimadzu is flexible enough to well serve regional-oriented or medium-sized companies in the same quality as ever.
Shimadzu has been doing business in US and Europe for over 40 years and our presence in these markets has dramatically improved in the last years, especially since we introduced the HPLC prominence series. We have sold more than 50,000 prominence pumps worldwide and are confident that the introduction of Nexera will boost our business expansion in the markets. In this context, a successful introduction at Pittcon and Analytica is critical to our future business.
With this new UHPLC system Shimadzu expands its product portfolio in the range of extreme performance and very high pressure systems. Please describe the most important features and capabilities of this instrument.
Dr. Masayuki Nishimura: Just two years ago, we introduced an UHPLC system providing 660 bar. Now, the new LC-30A Nexera is capable of providing a pressure of 1,300 bar up to 3 mL/min. We have almost doubled the pressure rating. This high pressure/flow rate range enables users to apply any existing and new methods. But pressure alone is not the decisive feature. In general, higher pressure rating provides more freedom in analysis, and high pressure can be responsible for higher productivity and throughput. However, the LC-30A represents highest performance without sacrificing other important features. It is a flexible system serving established and new methods. The system is the cleanest and fastest ever to date. Low carry-over, precise flow rates, ruggedness, long-term stability and high quality data are some of the outstanding features highlighting the performance. A new micro-reactor based mixer, fully developed components, best materials and technologies and new columns are important from the hardware side driving the performance. The users profit from the productivity and efficiency. The LC-30A is an easy-to-use system which can be directly applied by the user without unnecessary loss of time considering the application.
What kind of industry and markets do you wish to address and what will be its main fields of application?
Dr. Masayuki Nishimura: LC-30A Nexera meets the expectations of the most demanding markets such as pharmaceutical industry and its contract laboratories. Pharmaceutical industry is very demanding, not only because they have to run many samples, but also because they require the highest data quality since their products are used for the human body. Where human health is concerned, product safety, efficacy and availability are the key issues: people apply medical products to their skin, they inhale medicine or swallow pills. But we also have recognized the food industry as another important market. On one hand, the convenience food industry is a growth market in industrialized countries, and the monitoring of food quality and safety is important. On the other hand, we face a growing population on the Earth, and food safety will be a key and growing challenge in the future. In a nutshell: the Nexera system is a versatile tool for a multitude of different applications. It is the ultimate all-round LC.
Is the integration into an existing workflow possible at both software and mechanical end? For example, the coupling to high end mass spectrometers and sample preparation systems.
Dr. Masayuki Nishimura: The flexible modular design allows users to configure the system for virtually any applications. HPLC prominence series systems have been accepted by many customers as being the best MS frontend due to their high performance, flexibility and dependability. Nexera probably better fits the application because of its higher pressure tolerance, lower delay volume and even lower carryover. Its autosampler can be used with the rackchanger which accepts any type of micro titre plates (MTPs) with 96 or 384 wells which are commonly used with robotic systems in the lab, so that human intervention and thus human error can be minimized. The maximum number of samples which can be sent to the system is more than 4,600. The instrument is designed for real high throughput, meaning high speed and capacity.
What kinds of detector are available, and are they fully capable of extreme fast and short signals peaks?
Dr. Masayuki Nishimura: The well-established UV and PDA detectors of the prominence LC-20A series are available. Furthermore, the brand-new and worldwide most sensitive and fastest RF-20A/20AXS fluorescence detectors can be applied. Both series can be equipped with 100 Hz data acquisition rate. The temperature controlled flow cells guarantee a good signal to noise ratio and stable baseline for high-sensitive detection. MS respectively MS/MS detectors are preferred options which combine an increased separation capacity with adequate sensitivity.
Nexera has been designed for very high pressures. How did Shimadzu solve the typical problems such as leakages in valves and outlets, limited life spans of pumps and fittings or large dead volumes?
Dr. Masayuki Nishimura: Shimadzu has reviewed all the parts design and material. We have many different business groups such as Medical Systems, Aircraft and Industrial Machinery. We utilized our expertise in these fields to make Nexera rugged and reliable. We did not want to make UHPLC requiring special care and frequent maintenance. The fact that we continue to make all the key components such as injection valves, needle seals and pump heads also allows us to control the quality without compromise.
The new UHPLC comes with a new 1.6µm ODS column. What are the highest velocities and resolutions the user can obtain? What is your opinion in the general discussion on sub-2 µm-particles?
Dr. Masayuki Nishimura: We have developed Nexera to accommodate all existing and future methods by having highest pressure tolerance at high flow rate range. Users can use virtually any HPLC, UFLC and UHPLC methods. The system can be used with different particle columns such as sub-2 µm, sub-3 µm and fused core as well as traditional 3-5 µm columns.
We introduce a new XR-ODS series column with 2.2 µm particles (Shim-pack XR-ODS3) along with Nexera. XR-ODS3 is designed to be used under 1,000 bar to generate superior resolution. We believe that 2.2 µm particles are a good selection to maximize the productivity meaning resolution and speed.
Chromatography has become a routine method in all kinds of laboratories but has also reached its physical limits in many respects. In future, what would be necessary to bring this technology to a new level?
Dr. Masayuki Nishimura: Pressure is one parameter of future and better systems, but not the only one. We think multi-dimensional separation systems which drastically increase peak capacity will be more widely used. Sample pretreatment including dilution, reagent/standard addition and labeling will also be useful in reducing operators' workload. Higher productivity and lower maintenance will become standard in the near future as well as ready-to-use systems for immediate data acquisition. We will see wide-application universal systems, being at the same time environmentally friendly. In our eyes, this will take UHPLC technology to the next quality level, not just raising the bar through new levels of pressure.