seperation tqncs.. (pg. 1&2)

chromatography

separation of a mixture on the basis of specific differences of the physical-chemical characteristics of the different components on a supporting medium called adsorbent or sorbent

adsorbent/sorbent

is the medium that separates the analyte

chromatography

technique used to separate the analyte from the sample matrix before it can be analyzed

chromatography

the constituents of the mixture are separated by a continuous redistribution between 2 phases

stationary phase

where constituents are immobile or standing

mobile phase

which is also known as the eluent or carrier fluid

paper chromatography

a spot of the substance to be fractioned is placed on the paper just about the solvent level

paper chromatography

the organic solvent moves up through the paper by capillary action and various fractions in the sample move at different rates

moving phase

in paper chromatography the solvent is what?

stationary phase

in paper chromatography the paper is what?

paper chromatography

special grade filter paper acts as the sorbent

paper chromatography

used in the fractionation of sugar, amino acid, and barbiturates

gel permeation, size exclusion, molecular sieve, gel filtration, molecular exclusion

what are the other terms for gel chromatography ?

gel chromatography

a mixture of small and large molecules is allowed to pass over small particles or pores in a column

larger molecules

they tend to pair rapidly in the column, appearing in the eluate first

smaller molecules

they diffuse into the gel

gel chromatography

uses gels with pores of accurately controlled size as the sorbent

hydrophilic gels

are used in the separation of aqueous medium such as enzymes, antibodies, and other proteins

hydrophobic gels

are used in the separation of solute soluble only in organic solvents such as triglycerides and fatty acids

ion exchange chromatography

substances to be separated are passed on the ion exchange column

ion exchange chromatography

depending on the net charge and pH of the solution, the substance is absorbed from solution in the ion-charge resin

ion exchange chromatography

ions with greatest charge densities will be held most strongly on the ion-exchange material

ion exchange chromatography

sorbents include anion or cation resin with functional group

positive ions

will be trapped on the cation resin

negative resin

will be trapped on the anion resin

ion exchange chromatography

the basis of separation is the differences in sign and ionic charge densities

ion exchange chromatography

used for the separation of unwanted substances present in a solution mixture

ion exchange chromatography

concentration of solute of interest is suspended in highly diluted samples can be determined using this method

ion exchange chromatography

examples include the natural purification of water as it percolates through soil

thin layer chromatography

used for semiquantitive screening tests for drug screening

thin layer chromatography

sample components are identified by comparison with standards on the same plate

thin layer chromatography

when all drug spots, including the standards, have migrated with the solvent front, it is caused by using the incorrect aqueous to nonaqueous solvent mixture

thin layer chromatography

biological samples that can be used for the test include blood, urine, and gastric fluid

thin layer chromatography

sorbents used are thin plastic plates impregnated to a layer of silica gel, alumina, polyacrylamide gel, or starch gel

liquid liquid chromatography

follows the "like dissolves like" principle

like dissolves like principle

A highly polar substance tends to be more soluble in a highly polar solvent, like water

liquid liquid chromatography

basis of separation is the difference in solubility between two liquid phases,

liquid liquid chromatography

used for the fractionation of barbiturates and lipid studies

column chromatography

basis of separation include differences in pH, polarity of solvent

column chromatography

used in the fractionation of sugars

gas chromatography

capable of separating and measuring nanogram and picogram amounts of volatile substances

gas solid chromatography

uses a solid of large surface as the sorbent

gas liquid chromatography

uses nonvolatile liquids as the sorbent

gas chromatography

basis of separation include sample volatility, rate of diffusion into liquid layer of the column, packing, and solubility of sample gas in the liquid layer

gas chromatography

when coupled with mass spectrophotometry will be the confirmatory test for drugs

gas chromatography

used in drug screening and drug analysis

gas chromatography

also used in the fractionation of steroids, lipids, barbiturates, blood, alcohol, and other toxicology substances

high performance liquid chromatography

follows the concept of selective adsorption

high performance liquid chromatography

applies 4,000 to 10,000 lbs/in' pressure for the rapid identification and separation of high molecular weight components and many labile biologic compounds such as peptides, drugs, hormones, barbiturates, lipids, steroids, and antibiotics