Helmut Schulenberg-Schel, Ph.D., HPLC marketing manager at Agilent (www.agilent.com), sees productivity as the most significant economic driver for HPLC. Users want to streamline their workflow by spending less time on an experiment or getting more or better results using the same resources.
Globalization has accelerated standardization of HPLC methods, especially for organizations and collaborators that share information or protocols among multiple sites. Based on these needs, end-users now choose suppliers with the full range of hardware, software, instrument, and service capabilities.
Although speed and productivity matter to everyone, the omics disciplines are forcing users to dig more deeply into samples as well. It all depends on where the customer fits into the value chain, says Dr. Schulenberg-Schel. In many applications, for example in quality labs, standardization and methods optimization are everything. In QA you know what the goal is, but in research one must remove the onion skin one layer at a time.
While customers value bells and whistles, they also appreciate backward compatibility to help protect their instrument investment. Agilents 1200 Series LC is a case in point. The 1200 builds on the 1100 series model, which has sold 60,000 units worldwide. Customers can combine modules from both systems and continue to use methods developed on the 1100 without revalidation or retraining.
Agilent offers more than 60 instrument modules with the 1200, including a new rapid-resolution format as well as prep-scale, standard, narrow, capillary, nanoflow, and chip-based microfluidic HPLC. Agilent offers chips for small molecules as well as genes and proteins. According to Dr. Shculenberg-Schel, his companys nanospray HPLC-Chip/MS technology provides sensitivity gains 1,000-fold higher compared with conventional LC/MS.
Building on the success of the Zorbax Rapid Resolution High Throughput (RRHT) columns introduced three years ago, Agilent plans to debut 70 new advanced RRHT columns ranging from 1-mm to 4.6-mm internal diameter and from 20- to 150-mm length, with bonded phase particle sizes of 5, 3.5, and 1.8 mm.
Rising interest in sub 2-micron particles in solid phases allows a wider range of chromatography options, including greater efficiency over a wider linear dynamic range of flowrates. We see that across the board, whether its for standalone HPLC systems, LC/MS, or LC/MS/MS in front of triple quads or linear ion trap detectors, says Chris Loran, LC and LC/MS business director for Thermo Electron (www.thermo.com). The companys 1.9-m Hypersil GOLD columns, installed into Thermos Surveyor HPLC system, minimizes delay volumes to get the gradient from the pump, onto the column, and into the detector in less time, translating to shorter runs, according to Loran. Users can gain the advantages of small particles in a conventional system.
HPLC hardware and software continue to evolve toward greater simplicity and standardization. All Thermo systems use standard or open-source software, which Thermo says enables even novices to get up and running with a minimal learning curve.
As vendors strive to simplify HPLC operations, instruments IT requirements have become more demanding. Early HPLC instruments consisted of a pump, autosampler, column, injector, and UV detector. Todays photodiode array and MS detectors churn out more data than anyone can process by hand. A computer is essential for working with data from both types of detector, says Eksigent Technologies (www.eksigent.com) senior product manager Phil Deland. Temperature control is also becoming de rigueur, as peak widths of one to two seconds are susceptible to temperature artifacts. We dont see 20-second peaks any more, says Deland.
Waters (www.waters.com) continues to innovate on its UPLC (Ultra Performance LC) family of products. Introduced in 2004, UPLC features small stationary-phase particle sizes, and with smaller particles very high pressureup to 15,000 PSI. To achieve the higher resolution and efficiency of smaller particles you need higher pressure, says Jeffrey Mazzeo, Ph.D., director of applied technology. Thats UPLC.
UPLC was originally based on reverse-phase C18 chemistry, but in 2005 Waters debuted a C8 phase, phenyl, and what it terms shield chemistry or embedded polar phase, a variant of C18 featuring a carbamate group that provides unique selectivity. The company also introduced, for its Acuity UPLC product line, next-generation ultraviolet detectors with lower noise levels than traditional UV cells.
Normally, smaller particle size stationary phases require not just high pressure but minimal volume in the fluid path. Otherwise you get band broadening, losing all the benefits of the small particles, Dr. Mazzeo explains. Flow cell design must therefore trade off between an illumination volume large enough for stable detection, but not so large that it affects chromatographic behavior. Waters uses total internal reflectance to maximize the amount of sample the detector sees, while keeping the absolute volume low, in the hundreds of nanoliters.