Drug Screening Analyser
In October 2002, ESR's WDT laboratory commissioned a new state-of-the-art drug screening analyser to accommodate our increasing workloads. This Dimension RXL analyser continues to use the high quality Emit 11 Plus and Cedia immunoassay reagents. Significant efficiency improvements have been achieved by barcoding sample tubes and interfacing the analyser directly to our laboratory computer system.
Gas Chromatography-Mass Spectrometry
Gas Chromatography - Mass Spectrometry (GC-MS) is the technique used by ESR to 'confirm' the exact identity and concentration of drug metabolites in urine. The majority of drugs analysed for in Workplace Drug Testing samples (cannabis, opiates, amphetamines, cocaine ) are confirmed using this technique.
Confirmation of a drug metabolite is critical to give the client confidence that the laboratory result is specific, reliable and will stand up to legal scrutiny. GC-MS combines the separation of a drug from everything else in the urine and identification of the drug's characteristic molecular structure.
Drug metabolites are extracted from the urine into an organic solvent which is injected into the Gas Chromatograph where it is vapourised. A 'carrier gas' carries this vapour through a coiled chromatography column situated in a temperature-controlled oven. The column, often ten metres or more in length, allows different drug metabolites to pass through at different rates of travel.
At the end of the column, the now individually separated metabolites pass through the MS Detector where they are broken down into fragments depending on their chemical structure. This provides a specific fingerprint of the drug metabolite and allows the amount present to be measured. A positive or negative result is then reported.
Note:
Some confirmation testing is carried out using Liquid Chromatography-Mass Spectrometry (LCMS)