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level: Level 4

Questions and Answers List

LC AND HPLC

level questions: Level 4

QuestionAnswer
STATIONARY PHASE: packing material MOBILE PHASE : liquid simple, versatile, high resolution separationsLIQUID CHROMATOGRAPHY (LC)
LIQUID CHROMATOGRAPHY (LC) can be performed using either of 2 METHODS:1 Open column chromatography 2 HPLC
mobile phase is allowed to flow thru packed column under influence of gravityOpen column chromatography
– under high pressure - 1000 to 3000 psi required(High-performance liquid chromatography) HPLC
ADSORPTION CHROMATOGRAPHY 1 MOST COMMONLY used adsorbents for Thin-layer chromatographysilica gel and alumina
reverse phase is most frequently used method in HPLCPartition chromatography
HPLC Solvent reservoirs1 Glass or stainless container 2 Solvent w/ highest purity 3 Contain the mobile phase 4 Mobile phase should be filtered, degassed using vacuum and sonication
Straight length of stainless tubing 5 to 25 cm in length 2 to 4.6 mm in diameter C8 (Octyl) and C18 (Octadecyl) modified adsorbents – most popular, almost 80% HPLC operations have been developed w/ these adsorbents THE HEART of HPLC separation processAnalytical Column
most popular, almost 80% HPLC operations have been developed w/ these adsorbentsC8 (Octyl) and C18 (Octadecyl) modified adsorbents
detectors used in HPLC: Optical detectors:1 UV/VIS 2 IR/ raman 3 Optical activity 4 refractive index 5 Luminescent 6 Fluorescence
Mass Spectrometry detectors:1 Fourier Transform Ion Cyclotron Resonance 2 Mass spectrometry (FT-MS)
Elemental Detectors:1 AA/ Emission (Atomic absorption) 2 ICP-MS (Inductively coupled plasma mass spectrometry)
for oxidizable or reducible compound (catecholamines)Electrochemical Detectors
Electrochemical Detectors1 Conductivity 2 Coulometry 3 Polarography