Food Analysis: Test #1 Tables!

Technique

Chromatography

Output (i.e., signal v. time graph)

Chromatogram

Description of column and peak width produced

Efficiency

Narrow peak means

High efficiency

Broad peak means

Low efficiency

The thing doing the elution

Eluent

The thing removing analyte from column

Elution

Two analytes come off column and form overlapping peaks

Coellution

Change in relative concentration of solvent mixture over time

Gradient

Typically used with solid-phase technique (switch beakers)

Step gradient

Continual change in ratio of solvents over time

Continuous gradient

Unchanging ratio of solvents over time

Isocratic gradient

Time between sample injection and analyte/peak appearance

Retention time (tR)

Separation of two peaks (1.5 minimum for baseline resolution)

Resolution (Rs)

Signal between peaks drops to baseline

Baseline resolution

The ability of the column and mobile phase to separate a pair of analytes

Selectivity

Ability to measure only the analyte of interest

Specificity

What is the mobile phase for gas-liquid chromatography?

Gas

What is the stationary phase for gas-liquid chromatography?

Liquid

What is the mobile phase in gas-solid chromatography?

Gas

What is the stationary phase in gas-solid chromatography?

Solid

What is the mobile phase in reversed-phase chromatography?

Polar liquid

What is the stationary phase in reversed-phase chromatography?

Nonpolar liquid or solid

What is the mobile phase in normal phase chromatography?

Nonpolar liquid

What is the stationary phase in normal-phase chromatography?

More polar liquid or solid

What is the mobile phase in HILIC?

Less polar liquid

What is the stationary phase in HILIC?

More polar liquid or solid

What is the mobile phase in IEC?

Polar liquid

What is the stationary phase in IEC?

Ionic solid

What is the mobile phase in HIC?

Polar liquid

What is the stationary phase in HIC?

Nonpolar liquid or solid

What is the mobile phase in affinity chromatography?

Water

What is the stationary phase in affinity chromatography?

Binding sites

What is the mobile phase in SEC?

Liquid

What is the stationary phase of SEC?

Solid

What is the stationary phase in gas partition chromatography?

Polarity varies

What is the mobile phase in gas partition chromatography?

Gas

What is the gradient in gas partition chromatography?

Temperature

What is gas chromatography best for?

Volatile analytes

What is the stationary phase of NPLC?

Polar

What is the mobile phase of NPLC?

Nonpolar

What is the gradient in NPLC?

Nonpolar to polar

What is NPLC best for?

Very polar analytes

What is the stationary phase for RPLC?

Nonpolar

What is the mobile phase for RPLC?

Polar

What is the gradient in RPLC?

Polar to nonpolar

What is RPLC best for?

Nonpolar and moderately polar analytes

What is the mobile phase in adsorption chromatography?

Gas or liquid

What is the stationary phase in adsorption chromatography?

Solid

What is the amount of analyte stuck to the column in adsorption chromatography?

Fixed number of analytes stick

What is the analyte concentration dependency in adsorption chromatography?

Concentration dependent

What are the types of adsorption chromatography?

Normal phase only

What is the mobile phase in partition chromatography?

Gas or liquid

What is the stationary phase in partition chromatography?

Liquid

What is the amount of analyte stuck to column in partition chromatography?

Fixed percentage sticks

What is the analyte concentration dependency in partition chromatography?

Concentration independent

What are the types of partition chromatography?

Normal and reverse phase

What is the stationary phase charge of a cation exchanger?

-

What is the counter ion charge in cation exchanger?

+

What binds/retain (molec. charge) in cation exchanger?

+

What “exchanges” in cation exchanger?

Cations

What is the stationary phase charge in anion exchanger?

+

What is the counter ion charge in anion exchanger?

-

What binds/retains (molec. charge) in anion exchanger?

-

What “exchanges” in anion exchanger?

Anions

What is the mobile phase in NPLC?

Nonpolar

What is the stationary phase in NPLC?

Polar liquid

What is the gradient in NPLC?

Increasing polarity

What is the mobile phase in RPLC?

Polar

What is the stationary phase in RPLC?

Nonpolar liquid

What is the gradient in RPLC?

Decreasing polarity

What is the mobile phase in SEC?

Aqueous solvent

What is the stationary phase in SEC?

Porous particles

What is the gradient in SEC?

N/A

What is the mobile phase in IEC?

Aqueous solvent

What is the stationary phase in IEC?

+/- charged functional groups, coated with counter-ions

What is the gradient in IEC?

Change pH or increasing counter ion concentration

What is the mobile phase in HIC?

Salt buffer

What is the stationary phase in HIC?

Hydrophobic molecule bound to solid support

What is the gradient in HIC?

Decreasing salt concentration

What is the mobile phase in affinity?

Aqueous solvent

What is the stationary phase in affinity?

Ligand bound to silica

What is the gradient in affinity?

Change pH/ionic strength/temperature

What is the most common LC technique?

Reverse-phase (partition) chromatography

What is the transition measured in AAS?

Electronic

Is AAS molecular or atomic?

Atomic

Is AAS absorbance or emission?

Absorbance

What is being measured in AAS?

Light absorbed by atoms at a specific wavelength

What is the transition measured in AES?

Electronic

Is AES molecular or atomic?

Atomic

Is AES absorbance or emission?

Emission

What is being measured in AES?

Light emitted by excited atoms at a specific wavelength

What is the transition measured in fluorescence?

Electronic

Is fluorescence molecular or atomic?

Molecular

Is fluorescence absorbance or emission?

Emission

What is being measured in fluorescence?

Light emitted by molecules after they absorb light

What is the transition measured in Mid-IR?

Vibrational

Is Mid-IR molecular or atomic?

Molecular

Is Mid-IR absorbance or emission?

Absorbance

What is being measured in Mid-IR?

Light absorbed by molecules as their bonds undergo vibrations