HPLC Systems and Components Introduced at Pittcon 2010: A Brief Review

May 01, 2010
Volume 28, Issue 5, pg 376–385

Michael Swartz
Many high performance liquid chromatography (HPLC) vendors have for years coordinated their new product development cycle around the Pittcon schedule, planning to introduce new technology at the conference for the first time. Although the proliferation of additional, specialized conferences has altered this approach somewhat in recent years (for example, many new mass spectrometry [MS] new product introductions are now made at ASMS), Pittcon still remains a real must-go-to meeting to see the latest and greatest in HPLC and related technology. Because Pittcon attracts nearly 20,000 attendees from industry, academia, and government from over 90 countries worldwide, the conference provides a great opportunity for vendors to expose new HPLC products to both new and existing customers. For the attendees, the conference provides a venue to evaluate the latest instrumentation, compare vendors, participate in product demonstrations, and to speak with technical staff to resolve problems or investigate potential applications.

Table I: Summary of systems and components reviewed in this column
At this year's Pittcon, held February 28–March 5 in Orlando, Florida, several vendors introduced new systems and components, as well as product line extensions. In this installment of "Innovations in HPLC," I'll review some of the new HPLC instrument technology shown at the conference; new column and sample preparation technology will be reviewed by Ron Majors in his "Column Watch" column. The information in this review is partially based upon manufacturers' responses to a preconference questionnaire mailed in late 2009. I have used the information received in the questionnaires that were returned, as well as information from personal visits to as many vendors as I could during the conference to try to make this review as comprehensive as possible. But keep in mind that due to the fact that some manufacturers did not respond to the questionnaire, or do not release preshow information — and because of the the sheer size of the conference — this report cannot be considered an exhaustive listing of all new products that were introduced in Orlando. I'm bound to have missed a few items or details, so I'll apologize in advance for any omissions. Table I lists the product introductions reviewed in this column.

UHPLC Systems

HPLC is a proven technique that has been used in laboratories worldwide over the past 30-plus years. One of the primary drivers for the growth of this technique has been the evolution of packing materials used to effect the separation. As the column particle size decreases to less than 2.5 μm, not only is there a significant gain in efficiency, but the efficiency does not diminish at increased flow rates or linear velocities. By using smaller particles, speed and peak capacity (number of peaks resolved per unit time) can be extended to new limits. This technique is referred to as ultrahigh-pressure liquid chromatography (UHPLC) (1,2). UHPLC takes full advantage of chromatographic principles to run separations using higher flow rates and columns packed with smaller particles for increased speed and superior resolution and sensitivity. UHPLC was first introduced at Pittcon 2004 in Chicago, with the introduction of the Waters Acquity UPLC system (Waters Corp., Milford, Massachusetts) and reports claim that UHPLC systems will exceed 50% of the market by the year 2013. Several manufacturers have introduced UHPLC systems of their own in the years since 2004. This year in Orlando was no exception, where new systems, system variations, and components were introduced.

Figure 1
Building upon the success of the Prominence LC-20A Series, Shimadzu Scientific Instruments (Columbia, Maryland) introduced the Nexera UHPLC system, billed as an all-around HPLC system that enables various types of analysis including conventional HPLC, ultrafast LC, and UHPLC at pressures up to 19,000 psi, at flow rates ranging from 100 nL/min to 5 mL/min. The binary pump uses microsapphire plunger-driven pistons (10-μL pump head volume) in a parallel design, with mixing accomplished in an innovative low delay volume, ultrahigh-speed microreactor design, called the MiRC, as shown in the schematic in Figure 1. The XYZ-style injector features a through needle design with a fixed-loop option for fast analyses, with an injection cycle as short as 10 s, and injection volumes of 0.1–50 μL. To reduce the delay volume in the injector, an omega-shaped rotor design is used that reduces tubing lengths and the number of connections required. Up to three rinse liquids can be programmed to rinse the inside and the outside of the needle, as well as the injection port to minimize carryover. In pretreatment mode, the autosampler is also capable of performing precolumn derivatizations, additions of internal standards, and dilutions. The Nexera Rack Changer has temperature control (4–40 °C) and a capacity of up to 12 sample plates for a total of up to 4608 samples. The column oven can go up to 150 °C (nice for "green" 100% water mobile phase use), and has a two-column capacity. It incorporates a solvent preheater (referred to as the Intelligent Heat Balancer-IHB) that adjusts and balances the mobile phase temperature according to the flow rate and the column set temperature to minimize the affect of frictional heating at the head of the column. The total system delay volume is less than 42 μL with the ultra-low volume (20 μL) mixer, optional loop injection kit with 5-μL loop and microvolume preheater. Absorbance, fluorescence, and MS detector applications were shown.

Following in the footsteps of the innovative Acquity UPLC System, Waters (Milford, Massachusetts) introduced its next generation UHPLC instrument called the ACQUITY UPLC H-Class system. The H-Class system combines the flexibility of quaternary solvent blending and a flow-through-needle injector to bring the features of the original UPLC instrument to a wider HPLC audience. The ACQUITY UPLC H-Class was designed to allow organizations to standardize their approach to LC with a common technology platform that makes the future transition from HPLC to UPLC sub-2-μm technology-based methods straightforward and practical. The H-Class quaternary low-pressure mixing system uses a separate gradient proportioning valve for each solvent and a five-chamber integrated vacuum degassing system — four for the solvent lines, one dedicated to the injector needle wash for added precision. Flow can be programmed from 0.010 to 2.000 mL/min, in 0.001-mL/min increments, with a maximum operating pressure of 15,000 psi up to 1 mL/min, or 9000 psi up to 2 mL/min, with a total system volume of under 400 μL. For method development, the H-Class Quaternary Solvent Manager (QSM) can be used to prepare mobile phases on the fly, or "Autoblend," a technique that has been used in HPLC for many years. Premixing solvents during method development can be wasteful, as mobile phase combinations are tried that ultimately might not be used in the final method. Autoblend avoids having to discard unused mobile phase as individual neat solvents are used, making it easier to maintain pH and ionic strength and resulting in more robust methods. In addition, optional, integrated software-controlled solvent select valves increases to nine the number of solvents that can be evaluated during method development, and with the addition of column switching valves, the number of discreet methods that can be run on one system.

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