CC1-FINALS-READING CHROMATOGRAPHY AND MASS SPECTROMETRY

Question 1

has long been considered the gold standard for most testing due to its high sensitivity and specificity

Answer 1

Liquid or gas chromatography (GC) coupled to mass spectrometry (MS)

Question 2

Refers to the group of techniques used to separate complex mixtures on the basis of different physical interactions between the individual compounds and the stationary phase of the system.

Answer 2

CHROMATOGRAPHY

Question 3

Basic Components of CHROMATOGRAPHY

Answer 3

o Mobile phase
o Stationary phase
o Columns
o Separated components (eluate)

Question 4

types of MODES OF SEPARATION

Answer 4

• Adsorption
• Partition
• Steric Exclusion
• Ion-Exchange Chromatography

Question 5

Also known as liquid–solid chromatography, is based on the competition between the sample and the mobile phase for adsorptive sites on the solid stationary phase.

Answer 5

Adsorption

Question 6

Not widely used in the lab because of technical problems with the preparation of stationary phase that has homogenous distribution of absorption sites

Answer 6

Adsorption

Question 7

The molecules that are most soluble in the mobile phase move fastest; the least soluble move slowest.

Answer 7

Adsorption

Question 8

can be acidic polar, basic polar or nonpolar

Answer 8

Stationary phase

Question 9

can be a single solvent or mixture of two or more solvents, depending on the analytes to be desorbed

Answer 9

Mobile phase

Question 10

Also referred to as liquid–liquid chromatography. Separation of solute is based on relative solubility in an organic (nonpolar) solvent and an aqueous (polar) solvent.

Answer 10

Partition

Question 11

o Applicable to any substance that may be distributed between two liquid phases but works best with nonionic compound
o In its simplest form, partition (extraction) is performed in a separatory funnel.

Answer 11

Partition

Question 12

In Partition, ______ molecules remain in the aqueous solvent; __________ molecules are extracted in the organic solvent.

Answer 12

Polar; nonpolar

Question 13

uses pseudo-liquid stationary phases that are chemically bonded to the support or high-molecular-weight polymers that are insoluble in the mobile phase

Answer 13

Modern partition chromatography

Question 14

o Variation of liquid–solid chromatography, is used to separate solute molecules on the basis of size and shape.
o A sample containing different-sized molecules moves down the column dissolved in the mobile solvent

Answer 14

Steric Exclusion

Question 15

enter the pores in the packing and are momentarily trapped

Answer 15

Small molecules

Question 16

excluded from the small pores and so move quickly between the particles

Answer 16

Large molecules

Question 17

partially restricted from entering the pores and therefore, move through the column at and intermediate rate

Answer 17

Intermediate-sized molecules

Question 18

Uses hydrophilic beads of cross-linked dextran, polyacrylamide or agarose → forms gel when soaked in water

Answer 18

Gel filtration

Question 19

similar separation process using hydrophobic gel beads of polystyrene with a nonaqueous mobile phase

Answer 19

Gel permeation chromatography

Question 20

o Solute mixtures are separated by virtue of the magnitude and charge of ionic species

Answer 20

Ion-Exchange Chromatography

Question 21

o Anion-exchange resins are made with exchangeable hydroxyl ions such as the

Answer 21

diethylamine functional group

Question 22

o Stationary phase is a resin, consisting of large polymers of substituted benzene, silicates, or cellulose derivatives, with charged functional groups

o used to remove interfering substances from a solution, to concentrate dilute ion solutions, and to separate mixtures of charged molecules, such as amino acid

Answer 22

Ion-exchange chromatography

Question 23

variant of column chromatography. A thin layer of sorbent, such as alumina, silica gel, cellulose, or cross-linked dextran, is uniformly coated on a glass or plastic plate

Answer 23

Thin Layer Chromatography

Question 24

• Mobile phase (solvent) is usually placed in a closed container until the atmosphere is saturated with solvent vapor
• The solvent migrates up the thin layer by capillary action, dissolving and carrying sample molecules.

Answer 24

Thin Layer Chromatography

Question 25

• most commonly used as a semiquantitative screening test
• Plates prepared with uniform sorbent thickness, finer particles, and new solvent systems have resulted in the technique of high-performance thin layer chromatography (HPTLC)

Answer 25

Thin Layer Chromatography