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What methods do we use?

What methods do we use?

We offer our clients testing service options according to their unique and specific needs by including immunoassays as well as LC-MS/MS technology. We are continuously researching the drug of abuse market to keep abreast of the latest technology in drug of abuse testing. We are the first laboratory in South Africa that implemented a newly developed LC-MS/MS based drug of abuse testing system, setting new levels of sample throughput, sensitivity, specificity and flexibility. While GC-MS has been widely recognised as the “gold standard” in forensic testing, LC-MS/MS is now an established technique for screening and confirmation analysis and widely accepted in forensic toxicology laboratories for quantitative and confirmatory testing. 

LC-MS/MS benefits in comparison to GC-MS.

GC-MS Our LC-MS/MS assay
Sample preparationSamples need to undergo chemical derivatisation, increasing the risks for errors and prone to uncertainties such as reagent quality, presence of interferences and variable lab conditions -No derivatisation required
-Quicker and less extensive extraction procedures
-Ideal for polar and non-volatile molecules such as those analysed in drug of abuse testing
-Ability to identify a broader range of compounds
In the human body many drugs undergo glucuronidation requiring enzymatic or acidic hydrolysis of a sample before analysis. Hydrolysis varies in its effectiveness with the increased risk of false-positive or false-negative results.-The method we use involves an enzymatic hydrolysing process effective for hydrolysing all glucuronides within 2 hours
Sample preparation time6 hours daily (excluding hydrolysis) 2 hours daily
Sample volume1000 – 5000 µl 50 µl

In summary, with our LC-MS/MS method we offer:

  • Analyses of 109 drug of abuse metabolites in one run
  • Reliable hydrolysis
  • Simple sample preparation combined with high selectivity and sensitivity
  • Run times of 12 minutes
  • Inclusion of internal standards for 98 analytes with each run
  • Standardised and CE-IVD certified

We also included the Syva EMIT (enzyme multiplied immunoassay) technique within our testing scope as:

  • One of the most widely used and extensively validated in the industry
  • Medium cost instrument-based assay for high throughput with short analysis producing semi-quantitative results
  •  Appellate courts in the U.S. have recognized the scientific validity of the EMIT for analyzing urine, including with GC/MS and LC/MS/MS

Quality Assurance

Our methods are fully validated and verified within our own laboratory setting for meeting specific performance criteria. We take part in proficiency test schemes to independently assess our ability to accurately detect the drugs of interest.  Calibrators at 6 different levels, internal standards as well as quality control standards at three different levels, each with known target values for all the drug of abuse metabolites we test for and that need to comply with specified performance criteria, are included with each sample batch tested.