Getting Started in HPLC

Section 0. The Language of HPLC: M

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

   
MAIN COLUMN: See Analytical Column.


 
MEGAPASCAL (MPa): a unit of pressure; one MPa equals about 10 bar (atmospheres) or 150 pounds per square inch (psi).


 
METHANOL: one of three organic solvents commonly used (with water) to prepare reversed-phase mobile phases (see also ACETONITRILE and TETRAHYDROFURAN).


 
MICROGRAM (g): a unit of mass, equal to one millionth of a gram. See Section 4B for the relationship to other units of mass.


 
MICROLITER (L): a unit of volume, equal to 0.001 milliliter. See Section 4B for the relationship to other volume units.


 
MICRON (m): a thousandth of a millimeter or millionth of a meter; particles used as HPLC column packings have diameters of 3 to 10 microns (0.0001-0.0003 inches) for analytical columns.


 
MILLIGRAM (mg): a unit of mass, equal to 0.001 gram. See Section 4B for the relationship to other units of mass


 
MILLILITER (mL): a unit of volume, equal to 0.001 liters. See Section 4B for the relationship to other volume units.


 
MISCIBLE: two solvents are miscible if they combine with each other in all proportions to form a single phase; water and methanol are miscible, hexane and water are not miscible.


 
MOBILE PHASE: the liquid that flows through the LC system and column; it carries the sample from the column inlet to the detector. The mobile phase is usually a mixture of two or more solvents.


 
MOBILE PHASE STRENGTH: determines how fast the sample moves through the column; a STRONG MOBILE PHASE results in sample bands coming out fast, and a WEAK MOBILE PHASE gives longer retention times for each band. In the reversed-phase example shown below, 40% methanol/water is a stronger mobile phase than 30% methanol/water.
 

 
   
MODULE: a sub-unit of an HPLC system. The pump, injector and detector are all modules.


 
   
 

 


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Last revised: April 02, 2001.