Quick Review Cards for Medical Laboratory Science

Chromatography* Clinical Chemistry Review 77

TYPE COMPONENTS USE OTHER

Thin-layer chromatography

(TLC)

High-performance liquid

chromatography

(HPLC)

Gas chromatography

(GC)

Sorbent-coated glass or plastic

plate, closed container, solvent

Solvent, pump, injection port,

column, detector, recorder

Gas, injection port, column,

oven, detector, recorder

Screening test for drugs of

abuse in urine

Separation of thermolabile

compounds

Separation of volatile com-

pounds or compounds that

can be made volatile, e.g.,

therapeutic & toxic drugs

Substances identified by Rfvalue

(distance traveled by compound/

distance traveled by solvent).

Concentration determined by

peak height ratio (height of

analyte peak/height of internal

standard peak). Mass spectrome-

try (MS) can be used as detector

for definitive ID (LC/MS).

Compounds identified by reten-

tion time. Area of peak is propor-

tional to concentration. MS can

be used as detector for definitive

ID (GC/MS).

*Separation of compounds based on differential distribution between mobile phase & stationary phase.