Which of the statements is correct? Gas chromatography is used to analyse gases, solutions and solids All of these Gas chromatography is used to analyse gases Gas chromatography is used to analyse solids TRUE ANSWER : ? YOUR ANSWER : ?
Which of these effects result from slow injection of a large sample volume? Decreased resolution Non-linear detector response Constant resolution Increased resolution TRUE ANSWER : ? YOUR ANSWER : ?
Headspace analysis is carried out in order to analyse the column contents ahead of the sample determine the psychological state of the tutor determine non-volatiles analyse volatile compounds from solid or liquid samples TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following detectors give concentration-dependent signals? Electron-capture detector All of these Thermal conductivity Infra-red detector TRUE ANSWER : ? YOUR ANSWER : ?
In column switching chromatography the flow to the column is switched on and off repeatedly any of the above compounds trapped on one column are eluted to another column one column is removed and replaced by another TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following gases is unsuitable for use as a GC carrier gas? Oxygen Nitrogen Helium All of these TRUE ANSWER : ? YOUR ANSWER : ?
What useful information can be found from a Van Deemter plot? Optimum column temperature The selectivity factor Optimum column length Optimum mobile phase flow rate TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following detectors give mass flow-dependent signals? All of these Thermal conductivity detector Electron capture detector Field ionisation detector TRUE ANSWER : ? YOUR ANSWER : ?
Column bleeding occurs when traces of the stationary phase are eluted elution of the analyte is extended over time the column is cracked and stationary phase leaks out the column breaks during installation and causes personal injury TRUE ANSWER : ? YOUR ANSWER : ?
The column is heated to all of these control elution of the different analytes prevent analyte condensation within the column reduce band broadening to get sharper peaks TRUE ANSWER : ? YOUR ANSWER : ?