Urine Drug Test Types : Immunoassay & (GC/MS)

In today’s world, no one can hide anything. This is why it is advised to be a nice person inside out. If you are subjected to any malpractice or bad habit, it is going to come out someday. Hence, it is better to be truthful and stay away from such practices. A simple medical test today can bring out any secret of your body if you feel like you can hide it. So is the case with the use of drugs. Drug test through urine is the easiest way to look for drug traces in someone’s body. Even when the effect of drugs fades away, traces can still be found in urine.

Urine Drug Test Types

The two standard Urine Drug Tests include the Immunoassay and Gas Chromatography/Mass Spectrometry (GC/MS). Both are performed by laboratories worldwide. Their features are as follows-


It is the preferred initial test for urine drug screening. Positive results from an immunoassay test should be followed by gas chromatography/mass spectrometry or high-performance liquid chromatography. An extended opiate panel is needed to detect commonly used narcotics, including fentanyl (Duragesic), hydrocodone (Hycodan), methadone, oxycodone (Roxicodone, Oxycontin), buprenorphine, and tramadol(Ultram). Appropriate collection techniques and tests of specimen integrity can reduce the risk of tampering. 


  • Fast-  Unlike (GC/MS) immunoassay can give results in less time. We are saving one from a long wait for results and a course of treatment.
  • Inexpensive-  drug testing and medication can be expensive and can drain the family’s wealth real quick. Affordable immunoassay testing provides relief on the one hand.
  • Detects- This method reliably detects morphine, codeine, and heroin; however, it often does not see other opioids such as hydrocodone, oxycodone, methadone, fentanyl, buprenorphine, and tramadol.


  1. Test results can be false-positive and are found to be in several cases.

Chromatography/Mass Spectrometry (GC/MS)

Appropriate gas chromatography/mass spectrometry (GC/MS) analytical techniques can provide conclusive confirmatory evidence for the presence of drugs and metabolites in forensic urine drug testing. GC/MS is an instrumental technique rather than a specific methodology; many variations and instrumental configurations are possible. Knowledge of the advantages and pitfalls of different types of GC/MS systems and additional ionization and detection modes helps maximize accuracy and avoid false-positive and false-negative results.


  • Accuracy- GC/MS is the urine forensic drug test preferred for accuracy; even after performing immunoassay, samples are sent for this testing.
  • Determination- By this urine drug test, the exact percentage of different drugs present in the sample can be determined.
  • Detects- GS/MS detect drugs like hydrocodone, oxycodone, methadone, fentanyl, buprenorphine, tramadol, morphine, codeine, and heroin.


  • Expensive- Unlike immunoassay, GS/MS urine drug test is more accurate; hence it takes more time and, in comparison, is more costly.

Urine drug testing is the most painless method to detect drug percentage present inside the human body. Although it is time-taking at the end of the day, it is the most comfortable option available. Somebody’s drug addiction can be cured if tested at the right time, and those who come forward to get treated are the braves—cheers to their courage.

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