Question 19N.3.hl.TZ0.b
| Date | November 2019 | Marks available | [Maximum mark: 3] | Reference code | 19N.3.hl.TZ0.b |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Describe | Question number | b | Adapted from | N/A |
Steroids are lipids with a steroidal backbone. The structure of cholesterol is shown in section 34 of the data booklet.
Describe a technique for the detection of steroids in blood and urine.
[3]
Any three of:
sample/liquids vaporized «in oven/at high temperature»
OR
sample injected into mobile phase/inert gas
OR
nitrogen/helium/inert gas acts as mobile phase
OR
sample carried by inert gas «through column» ✔
NOTE: Award [1 max] for identifying suitable technique (eg GC-MS etc.).
Do not accept just “gas”.
Accept description of HPLC using liquid mobile phase.
stationary phase consists of a packed column
OR
packing/solid support acts as stationary phase ✔
NOTE: Accept named stationary phase, such as «long-chain» hydrocarbon/polysiloxane/silica.
components separated by partition «between mobile phase and stationary phase»
OR
gases/liquids/components have different retention times/Rf
OR
gases/liquids/components move through tube/column at different speeds/rates ✔
detector/mass spectrometer/MS «at end of column»
OR
databases/library of known fragmentation patterns can be used ✔
NOTE: Accept “area under peak proportional to quantity/amount/concentration of component present «in mixture»”.
