Glossary

Based on the most recent recommendations of the International Union of Pure and Applied Chemistry (IUPAC), which appeared in Pure and Applied Chemistry 65: 819-872 (1993). A Eddy diffusion, or packing factor term of the van

Deemter (packed column) equation. « Separation factor; the adjusted retention time of the more retained solute relative to that of the less retained solute.

B Longitudinal diffusion term of the van Deemter and Golay equations.

P Column phase ratio. The column volume occupied by mobile (gas) phase relative to the volume occupied by stationary phase. In open-tubular columns:

cM, cS Solute concentrations in mobile and stationary phases, respectively.

C Resistance to mass transfer (or mass transfer) in the van Deemter (or Golay) equations; Cm and CS denote mass transfer from mobile to stationary and from stationary to mobile phases, respectively.

dc Inner diameter of the column. Both mm and |im are commonly used. The latter, while consistent with the units used for df, implies three significant figures, which is rarely true.

df Thickness of the stationary phase film, usually in | m.

D Diffusivity; DM and DS denote solute diffusivities in the mobile and stationary phases, respectively; usually given in cm2 s_1.

F Volumetric flow of the mobile phase, usually in cm3 min-1. Many practical chromatographers assume equivalency with (and hence employ) mL min-1.

FID Flame ionization detector.

GC-MS The combination of gas chromatography and mass spectrometry, usually a single integrated unit in which fractions separated by GC are sequentially introduced to the MS.

H Length equivalent to one theoretical plate (height equivalent to a theoretical plate): H = L/N. When measured at uopt, the result is termed Hmin.

k Solute retention factor (formerly partition ratio). Ratio of the amounts of a solute (or time spent) in stationary and mobile phases, respectively. Because all solutes spend tM time in the mobile phase, k = [tR- tM]/tM, and k = tR/tM.

Kc Distribution constant. Formerly KD. Ratio of solute concentrations in stationary and mobile phases, respectively: Kc = cS/cM.

P. Husek, Institute of Endocrinology, Prague, Czech Republic

Copyright © 2000 Academic Press

Solar Panel Basics

Solar Panel Basics

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