Focus GC as juniors! The reason is that they are affordable. That's a price-to-value ratio that you can't turn down." McNair also had kind words for software maker Nelson Analytical: "That's fantastic, what's going on there, that growth! Why is that? Be cause [Nelson software] does some simple things at a reasonable cost in a very straightforward fashion."
• · Do you want to inject chicken fat into your LC column? Try it on an HPTLC plate first. You can throw that away. % ·
LC "Was that a gimmick from PerkinElmer (PE) two years ago?" asked McNair in reference to the fast liquid chromatography (LC) columns (3 cm long, filled with 3-μηι particles) intro duced by the company at that time. "Nobody's doing fast LC per se—five peaks in six seconds—but the idea was revolutionary: short columns, small particles, fast analysis. That is a major trend; you will see more of these systems." McNair pointed out that fast LC systems can provide a large number of theoretical plates along with the additional advantages of fast er analyses, lower solvent consump tion, and smaller pressure drops across the column. Perhaps his most controversial statement of the morning involved mi-
crobore LC (5), a technology that LC manufacturers have embraced every bit as warmly as the consumer prod ucts companies have embraced soft chocolate chip cookies. Of course, some of the new soft chocolate chip cookies taste worse than the old hard cookies, and McNair feels the same way about microbore vs. conventional LC: "For me, [microbore] is a very small segment—I think it's more fad than fact. People do like the lower sol vent consumption. OK, use the 2-mm," said McNair, referring to the 2-mm-i.d. microbore columns that can be used on conventional LC equip ment. (Microbore columns of 1-mm i.d. and less require specially modified
chromatographs to obtain optimum resolution and sensitivity.) "Unfortunately," said McNair later, "some of the manufacturers have tout ed microbore as being higher in sensi tivity and better in resolution, which is not true in all situations. The true advantages of microbore are solvent savings and for use with very limited amounts of sample. For unlimited samples, larger masses can be applied to regular columns, resulting in com parable sensitivity to that obtained with microbore columns." People do like the interface possi bilities of microbore LC, but hyphen ated techniques such as LC-mass spectrometry (LC/MS), LC-nuclear magnetic resonance spectrometry (LC/NMR), and LC-Fourier trans form infrared spectrometry (LC/FTIR) are not dependent on microbore technology, according to McNair. "It's not just the column technology, it's a little more complicated," he ex plained. "We're looking at the com patibility of two different instru ments, including the compatibility of solvent systems used in LC with spec troscopic systems. Microbore is not proving to be a true quantum leap over regular columns in terms of inter:§**·•
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ANALYTICAL CHEMISTRY, VOL. 57, NO. 6, MAY 1985 · 667 A
