logojp2.gif (10048 bytes)















































































































































1


                                           

    Terminologies

Because of the complex nature of Toxicology, we have included a terminology section that would help you understand the process of drug testing, methods, etc. We will try to cover the most common terms that are used in dealing with drug testing. If there are particular terms that are not included in this section, or if you have any questions please call us.

1. Adulterants - these are substances that alter the nature of the sample (urine) to give a false negative result. The most common substance is Zydot solution, which is taken internally. It works by covering or masking the drug to avoid detection, thus resulting in a false negative drug test result. Zydot and similar detoxifying solutions consist of sugars, starches, other ingredients. In order to be effective, a person would drink the Zydot solution and allow at least one hour for the solution to circulate the system. Thereafter, he or she must submit to a drug test within four hours to ensure false negative results. Other substances that has the same effect as Zydot is Klear, Whizzies, and Detoxify.

Testing for the presence of adulterants can be an expensive process. Most labs test for the presence of adulterants by testing for nitrites in the urine. A positive Nitrite test can indicate possible use of an adulterant. However, Nitrites are naturally occurring substances. In order to confirm drug use or abuse, a confirmation method must be done for each Controlled Substances. This is costly and time consuming, and laboratories doing the test are not apt to run several confirmation, especially if they are only charging $10.00 per sample.

2. AlphaTox Method - This is a method that was developed at Toxicology Associates, Inc. as a counteractive measure against adulterant, and a way to eliminate false negative and positive drug test results that are often seen in the Immunoassay method. For more details, please see Beating the Drug Testing System section.

3. Classes of Drugs - Drugs are classified depending on their action. For example, the drug Acetaminophen (Tylenol) relieves pain. Therefore, Acetaminophen belongs to a Class of Drugs called Analgesics. Other classes of drugs include Barbiturates, Benzodiazepines, Opiates, etc.

4. Confirmation - A process in which a positive drug test on the initial method must be confirmed by another method. For example, an initial method would be Immunoassay and a confirmation method is by Gas Chromatograph Mass Spectrometry (GC/MS). Confirmation assures 100 % confidence in results. STATE OF OHIO LAW REQUIRES CONFIRMATION ON ANY POSITIVE DEA CONTROLLED SUBSTANCES.

5. Controlled Substances - These are drugs that are classified by US Drug Enforcement Agency (DEA) as illegal substances, and are the most common drugs that are screened for employment/pre-employment, etc. It includes Amphetamines, Barbiturates, Benzodiazepines, Cannabinoids, Cocaine, Meperidine, Methadone, Opiates, Phencyclidine (PCP), and Propoxyphene.

6. Concentration - The amount of substance in a given volume of a sample. This can be expressed in different forms such as nanograms per milliter (ng/ml), micrograms per milliliter (ug/ml), etc. As an example, if the urine drug screen revealed a positive result for Cocaine the level would be indicated by "Positive Cocaine at level of 200 ng/ml". In other words, there are 200 ng of Cocaine substance in one milliliter of liquid (blood, urine).

7. Cut - Off Levels (Limit of Sensitivity) - The lowest concentration of a substance that an instrument is capable of detecting. This varies depending on the type of drug and the method of detection. A drug level below the Cut-Off limit is considered Non-Detect. Likewise, drug level above the Cut-Off limit is a positive result. For example, if the Cut-Off limit for Cocaine is 300 ng/ml, result below the Cut-Off limit is Non-detect, and above the limit is a positive result.

The more sensitive the instrument the better, because it is the only way to determine whether or not there is a drug used. This is very important, especially if a drug has been consumed several days ago where the concentrations of the drug has declined significantly. Indeed, excellent sensitivity can only be achieved through instruments of Gas Chromatography and Gas Chromatography Mass Spectrometer (GC/MS).

8. False Negative Result - A result in which the drug(s) of interest, if present, is either altered or covered to avoid detection. Adulterant is a good example of causing a false negative result.

9. False Positive Result - An interaction in which drugs or other substances can interfere with other drugs or substances, to yield a false positive result. As an example, if a person is taking multiple drugs simultaneously can possibly cause interference to give a false positive drug test result. Generally, false positive results are more prominent in methods of Immunoassay. (See Immunoassay section).

10. Gas Chromatography (GC) - A method for analyzing drugs. This is very accurate and has an excellent sensitivity of detecting drugs next to Gas Chromatography Mass Spectrometry (GC/MS). The main advantage of the GC is its superb immunity to adulterants and multiple presence of drugs that can potentially cause a false negative and false positive results, respectively.

11. Gas Chromatography/Mass Spectrometry (GC/MS) - This the latest, most advanced, and sophisticated analytical instrument today. GC/MS's superior accuracy and sensitivity is unmatched by all other scientific instruments. Additionally, GC/MS is the only federally approved form of confirmation of drugs. Therefore, it is highly recognized and respected in any court system including the United States Supreme Court.

Why is GC/MS such a superb instrument? Recall that analyzation of drugs, especially using the Immunoassay method does not guarantee an accurate result at all times, because of adulterants, and multiple presence of drugs and/or other substances. GC/MS can identify with superb accuracy the type of drug(s) in a sample. Think of GC/MS as looking at someone's face. The face you are looking at is exactly what it looks like, as opposed to a description of what the face looks like.

It is highly recommended that a laboratory doing drug testing confirms a positive drug results at least by GC/MS. Beware of laboratories that only use the Immunoassay method without the GC/MS confirmatory method.

11. Immunoassay Method (IA) - This method is an inexpensive, quick, and simple way of analyzing drugs in the system. It can analyze several samples at the same time, as many as 600 samples per hour compared to the GC which can only analyze one sample at a time. For these reason, most labs that do drug screening use the IA method. Unfortunately, the IA lacks accuracy and sensitivity that can only be achieved through GC and GC/MS. Above all, the IA is prone to false negative and positive results, a problem that is inherent with this method. The following will help identify the area of troubles.

NEXTarrowsrt.gif (3348 bytes)

 

 

 


Copyright 1999 [Toxicology Associates, Inc.]. All rights reserved.
Revised: January 13, 2010