Reference no: EM133027367
Forensic Chemistry Assignment - Caffeine analysis by GCMS
Objectives -
1. Extract caffeine, theophylline and theobrominefrom equine urine.
2. Indentify caffeine, theophylline and theobromine in the equine urine extract.
3. Quantify the levels of caffeine, theophylline and theobromine in the equine urine extract.
4. Make a deduction as to whether the case is an intentional use or unintentional use
PROCEDURE - Solvent Extraction
1. Pipette 5mL each of sample urine and negative control urine in numbered 16 x 125mm test tube. Prepare appropriate positive control.
2. Add 2mL of pH 6 buffer.
3. Add 5mL of Dichloromethane:Isopropanol (DCM:IPA) (3:1).
4. Rotorack slowly for 5 minutes, centrifuge 10-15 minutes, aspirate top aqueous layer
5. Transfer to clean disposable culture tubes.
6. Evaporate each sample to dryness (650C concentrator) under a gentle stream of Nitrogen gas.
7. Reconstituted with methanol and analysed by GC-MS using HP 5MS column.
Calibration Standards - Prepare calibration solutions in the range 1 - 100 ppm from a stock solution of 1000 ppm caffeine standard.
Control sample - Perform extraction and GC analysis on control sample.
Recovery Analysis - Determine recovery by spiking control sample with 200uL of 10ppm standard, extract and run on GC.
Blank - Select a suitable blank and extract and analyse by GCMS.
Attachment:- Caffeine Analysis Assignment File.rar