LCGC North America-12-01-2007

For the last six months, "LC Troubleshooting" has been concentrating on the process for the development of isocratic methods (those for which the mobile phase composition is constant throughout the run). The use of a gradient scouting run to speed isocratic method development is the subject of this month?s "LC Troubleshooting."

Millipore Corporation (Billerica, Massachusetts) announced the availability of the new Milli-Q Integral water purification system, which uses tap water to supply constant-quality Type II (pure) and Type I (ultrapure) water from a single water production unit.

This installment of "Validation Viewpoint" column addresses, in the hopes of clarifying what the biopharmaceutical industry is required to do today to identify and quantify impurities in their biotech, proteinaceous products.

Nearly a dozen incipient technologies have appeared in recent years. Which will survive? Which will find extensive, robust usage as did electrospray ionization? Which are fated to become footnotes in mass spectrometry practice?

Thin layer chromatography (TLC) is a planar chromatographic technique introduced in the 1950s as a fast, easy, and inexpensive method for qualitative analysis. Just as with column chromatography, the chemistry and size of the particles (as well as the thickness of the layer) affects the speed and nature of the separations that are possible.

In this month?s installment, columnist Ron Majors covers the field of immunoextraction, a technique that employs immobilized antibodies to selectively capture specific analytes using molecular recognition via antibody?antigen interactions. Recently, the introduction of commercial products for specific high-volume environmental and food safety applications has spurred further applications of this technique.