Drug testing

• What samples can be taken for drug testing

  Hair.

  Blood.

  Urine.

  Saliva.
• What are the pros and cons of blood for drug testing.

  It is invasive. But it is difficult to add adulterants.
• What are the pros and cons of Urine for drug testing.

  It is non-invasive.

  And adulterants can easily be added to invalidate the test.
• What are the pros and cons of Saliva for drug testing.

  It is non-invasive.

  Only a limited number of analytes will accumulate in the saliva.
• What are the pros and cons of Hair for drug testing.

  It is non-invasive. But a limited number of analytes accumulate in the hair.
• What is an adulterant

  A substance which can be mixed with the sample and invalidate the result.
• what is DOA testing

  Testing for drugs of abuse.
• What are the steps in DOA testing

  1. Sample
  2. On-site testing
  3. Confirmatory analysis
• Describe on-site testing

  It is an immunoassay based test.

  Only gives you the class of drug with certainty.

  Adulterants can obsucre the result.
• Briefly describe confirmatory analysis

  Uses chromatography to separate compounds.

  Spectroscopy is used to confirm the identity of the substance.
• What is the other name for on-site testing

  Point of care screening
• What are the main differences between screening and confirmatory tests

  Screening tests can be done on-site, whereas confirmatory tests can only be done in a lab. And so screening tests are quicker and cheaper.

  Confirmatory tests give you a definitive identity whereas screening tests only tell you the class of drug.

  Both tests are sensitive; however, screening tests lack specificity due to adulterants.

  Both tests are qualitative but screening tests are only semi-quantitative.
• Which test has a higher cut-off limit

  Screening test
• What is a cut off limit in drug testing

  The amount of a substance that can be detected.
• How is the identity of a drug identified

  Using Mass spectroscopy, Chromatography or spectroscopy with infrared.
• What types of chromatography are used in drug identification

  GC - MS, HPLC - MS.
• How is the abundance of a drug identified

  Using chromatography and spectroscopy using UV and visible light.
• What type of drug testing is lateral flow technology used for

  On-site testing
• Describe the structure of a biochip for DOA testing

  Each biochip contains an array of discrete test regions (DTRs) which have a different analyte test.

  Each chip can produce 49 tests.
• Describe how the biochip is used for DOA testing

  The discrete test regions have an antibody which binds the analyte.

  An enzyme-labelled antibody will bind to the analyte.

  This produces light and the intensity is measured to quantify the amount of the drug present.
• What causes cross-reactivity in DOA testing


  When two different drugs have a similar epitope to the antibody.
• Which drugs produce cross-reactivity with 6-MAM

  Morphine.

  Heroin.

  Codeine.
• Define chromatography

  Separation of substances based on affinity for the mobile phase versus the stationary phase.
• What is the solute in chromatography

  The sample
• What is the solvent in chromatography

  The mobile phase
• What is the stationary phae

  The phase which does not move
• What is the mobile phase

  The phase which moves it can be liquid or gas. The sample is dissolved in this phase.
• What are the main types of chromatography

  Gas.

  High-performance liquid.

  Thin layer / Planar.

  Affinity.

  Ion exchange.
• What type of chromatography is this?

  Thin layer, which may be known as a planar.

  A) Origin

  B) Mobile phase

  C) Thin layer plate

  D) Thin layer tank

  E) Lid

  F) Solvent front

  
• How is TLC used in DOA testing

  Spray reagents are used to produce different colours for the analytes.
• How long is heroine in the urine for

  less than 30 minutes
• How long is 6-MAM in the urine for

  24 hours
• How long is morphine in your urine for

  5 days
• What is the additional ingredient in Nurofen plus

  Codeine.
• What is codeine metabolised into

  Morphine
• How does infrared spectroscopy identify drugs

  The wavenumber from the peaks is related to the groups within the drug.